Re: [MBZ] Glow Plug Testing
AH HA! Stop the presses. A success story from me! Replaced the last/front glow plug, still no go 0v on it. So I cleaned up the ground from the last/front glow plug. Turned the key and had a glow light and all the schmutz on the toaster wire and the two new glow plugs instantly started smoking. Then she started right up like nothing ever happened. Thanks for your patience and good explanations, Jim. If you were closer I'd buy you an adult beverage or a cup of Joe. Bob R -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Cathey Sent: Friday, November 28, 2008 10:32 AM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing > Been messing with the glow plugs again. When I turn the key, I show > 12v at > the goes-in of the 50 amp fuse, 12v at the goes-out of the fuse and > 12v at > each of the glow plugs except the one at the front of the engine which > shows > 0v (the plug that goes to ground). > Does that tell me anything? It tells you that you have an open circuit. The series glow plugs (and toaster racks) are the rungs on a ladder stretching between 12V and ground. (Think roof and ground.) What do you have to do in order to get the bottom rung of the ladder on the ground, and all the rest at roof level? Cut the ladder and flip the top part up horizontally, that's what. (Now, how well does this modified ladder work for climbing? Not at all.) Open circuit, in other words. You have a break in between the last part at 12V and the first part at 0V. The initial suspicion is a burned-out glow plug on #2, but a very bad connection to #2 (either one) could do it. The toaster racks are unlikely to be bad, certainly not without being visibly so. It is usually sufficient, and usually easier, to use the voltmeter to verify that the first glow plug (from the fuse) is getting 12V measured to ground. Thereafter you measure _across_ the two terminals of each glow plug, nominal is about 1V each. Any plug that shows more than 1V across it is bad, and will imply that at least one other plug will have less because of the 'theft'. (If you had a shorted plug, which is a lot rarer, you'd see 0V across that plug and all the others at 1.3V or so. That's the exception to the >1V == bad rule.) I've seen cases where one plug has 2V or so on it, and others have less than 1V. The 2V plug had internal corrosion on it, stealing voltage (if you will) from the others. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Been messing with the glow plugs again. When I turn the key, I show 12v at the goes-in of the 50 amp fuse, 12v at the goes-out of the fuse and 12v at each of the glow plugs except the one at the front of the engine which shows 0v (the plug that goes to ground). Does that tell me anything? It tells you that you have an open circuit. The series glow plugs (and toaster racks) are the rungs on a ladder stretching between 12V and ground. (Think roof and ground.) What do you have to do in order to get the bottom rung of the ladder on the ground, and all the rest at roof level? Cut the ladder and flip the top part up horizontally, that's what. (Now, how well does this modified ladder work for climbing? Not at all.) Open circuit, in other words. You have a break in between the last part at 12V and the first part at 0V. The initial suspicion is a burned-out glow plug on #2, but a very bad connection to #2 (either one) could do it. The toaster racks are unlikely to be bad, certainly not without being visibly so. It is usually sufficient, and usually easier, to use the voltmeter to verify that the first glow plug (from the fuse) is getting 12V measured to ground. Thereafter you measure _across_ the two terminals of each glow plug, nominal is about 1V each. Any plug that shows more than 1V across it is bad, and will imply that at least one other plug will have less because of the 'theft'. (If you had a shorted plug, which is a lot rarer, you'd see 0V across that plug and all the others at 1.3V or so. That's the exception to the >1V == bad rule.) I've seen cases where one plug has 2V or so on it, and others have less than 1V. The 2V plug had internal corrosion on it, stealing voltage (if you will) from the others. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Been messing with the glow plugs again. When I turn the key, I show 12v at the goes-in of the 50 amp fuse, 12v at the goes-out of the fuse and 12v at each of the glow plugs except the one at the front of the engine which shows 0v (the plug that goes to ground). Does that tell me anything? Bob R '77 300D 196K -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Cathey Sent: Monday, November 24, 2008 11:34 PM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing > So I finally tested the glow plugs. > The readings, from back to front, were as follows: > 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash > What does that mean? Time to replace glow plugs? The 2V one is probably corroded inside, and will probably need to be replaced. The 0V one is shorted, but it's possible that you have something wrong with the external wiring to it. Give that a once-over carefully. Else, replace it too. The lamp is lit by the relay, which senses the current to the string. Looks to me like your two non-functioning plugs cancel each other out, current-draw-wise, so shouldn't be responsible for the lamp not lighting. Is the bulb good? These relays also use a head temperature sensor to tell them how long to glow the light. Maybe it is 'full hot', open or shorted, whichever that would be, and thus doesn't run the light. Otherwise, once the glow plugs themselves are sorted out, it's got to be the relay itself. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Can you tell me where that temp sensor is located? Screws into the middle of the head, near the glow plugs. There is more than one, so be sure you're looking at the right one. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Jim C told me: "These relays also use a head temperature sensor to tell them how long to glow the light. Maybe it is 'full hot', open or shorted, whichever that would be, and thus doesn't run the light." Can you tell me where that temp sensor is located? Going to replace the glow plugs while making pumpkin pies. Bob R ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
I've forgotten, what car is this in? The W115 300D does not use current draw to turn the GP lamp on, it's on a separate temperature sensor that screws into the head and operates pretty much by heat from the coolant and theoretically from the current heating a bimetallic spring. It's a temperature dependent timer only, and quite often the contacts in the sensor fuse and it stays on until you crank the engine whether or not the GPs are energized. It will come on even if the glow plugs are disconnected or open, unlike the later "smart" relays, were the lamp will not light if there isn't enough current draw. I've not played with one of these yet. My 115 200D has the knob. The only key-start series system I've played with was the Albatross, a 123 240D. I had to work on its relay, so I remember how it's built inside. If you care about the details, see: http://userweb.windwireless.net/~jimc/mb240d.html#10Mar2006 -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
It's the W123 300D -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Peter Frederick Sent: Monday, November 24, 2008 11:56 PM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing I've forgotten, what car is this in? The W115 300D does not use current draw to turn the GP lamp on, it's on a separate temperature sensor that screws into the head and operates pretty much by heat from the coolant and theoretically from the current heating a bimetallic spring. It's a temperature dependent timer only, and quite often the contacts in the sensor fuse and it stays on until you crank the engine whether or not the GPs are energized. It will come on even if the glow plugs are disconnected or open, unlike the later "smart" relays, were the lamp will not light if there isn't enough current draw. Peter On Nov 25, 2008, at 12:34 AM, Jim Cathey wrote: >> So I finally tested the glow plugs. >> The readings, from back to front, were as follows: >> 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash >> What does that mean? Time to replace glow plugs? > > The 2V one is probably corroded inside, and will > probably need to be replaced. The 0V one is shorted, > but it's possible that you have something wrong with > the external wiring to it. Give that a once-over > carefully. Else, replace it too. > > The lamp is lit by the relay, which senses the current > to the string. Looks to me like your two non-functioning > plugs cancel each other out, current-draw-wise, so shouldn't > be responsible for the lamp not lighting. > > Is the bulb good? These relays also use a head temperature > sensor to tell them how long to glow the light. Maybe it is > 'full hot', open or shorted, whichever that would be, and thus > doesn't run the light. > > Otherwise, once the glow plugs themselves are sorted out, > it's got to be the relay itself. > > -- Jim > > > > ___ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Thanks Jim. Good explanation. Now all I need is a day off to mess with it. I'll be busy making electricity while yous guys are dining with your families. Eat like mad. Bob R -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Cathey Sent: Monday, November 24, 2008 11:34 PM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing > So I finally tested the glow plugs. > The readings, from back to front, were as follows: > 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash > What does that mean? Time to replace glow plugs? The 2V one is probably corroded inside, and will probably need to be replaced. The 0V one is shorted, but it's possible that you have something wrong with the external wiring to it. Give that a once-over carefully. Else, replace it too. The lamp is lit by the relay, which senses the current to the string. Looks to me like your two non-functioning plugs cancel each other out, current-draw-wise, so shouldn't be responsible for the lamp not lighting. Is the bulb good? These relays also use a head temperature sensor to tell them how long to glow the light. Maybe it is 'full hot', open or shorted, whichever that would be, and thus doesn't run the light. Otherwise, once the glow plugs themselves are sorted out, it's got to be the relay itself. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
I've forgotten, what car is this in? The W115 300D does not use current draw to turn the GP lamp on, it's on a separate temperature sensor that screws into the head and operates pretty much by heat from the coolant and theoretically from the current heating a bimetallic spring. It's a temperature dependent timer only, and quite often the contacts in the sensor fuse and it stays on until you crank the engine whether or not the GPs are energized. It will come on even if the glow plugs are disconnected or open, unlike the later "smart" relays, were the lamp will not light if there isn't enough current draw. Peter On Nov 25, 2008, at 12:34 AM, Jim Cathey wrote: So I finally tested the glow plugs. The readings, from back to front, were as follows: 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash What does that mean? Time to replace glow plugs? The 2V one is probably corroded inside, and will probably need to be replaced. The 0V one is shorted, but it's possible that you have something wrong with the external wiring to it. Give that a once-over carefully. Else, replace it too. The lamp is lit by the relay, which senses the current to the string. Looks to me like your two non-functioning plugs cancel each other out, current-draw-wise, so shouldn't be responsible for the lamp not lighting. Is the bulb good? These relays also use a head temperature sensor to tell them how long to glow the light. Maybe it is 'full hot', open or shorted, whichever that would be, and thus doesn't run the light. Otherwise, once the glow plugs themselves are sorted out, it's got to be the relay itself. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
So I finally tested the glow plugs. The readings, from back to front, were as follows: 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash What does that mean? Time to replace glow plugs? The 2V one is probably corroded inside, and will probably need to be replaced. The 0V one is shorted, but it's possible that you have something wrong with the external wiring to it. Give that a once-over carefully. Else, replace it too. The lamp is lit by the relay, which senses the current to the string. Looks to me like your two non-functioning plugs cancel each other out, current-draw-wise, so shouldn't be responsible for the lamp not lighting. Is the bulb good? These relays also use a head temperature sensor to tell them how long to glow the light. Maybe it is 'full hot', open or shorted, whichever that would be, and thus doesn't run the light. Otherwise, once the glow plugs themselves are sorted out, it's got to be the relay itself. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Very well. What about the no light on the dash when the key is turned? Would the two bad glow plugs cause that? Bob -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Loren Faeth Sent: Monday, November 24, 2008 7:37 PM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing Replace the second and 4th plugs in order of testing. At 08:30 PM 11/24/2008, you wrote: >So I finally tested the glow plugs. >The readings, from back to front, were as follows: >1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash >What does that mean? Time to replace glow plugs? > >Bob R >'77 300D > >-Original Message- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >On Behalf Of Jim Cathey >Sent: Saturday, November 22, 2008 10:54 PM >To: Mercedes Discussion List >Subject: Re: [MBZ] Glow Plug Testing > >Diagnosing a series glow plug system is very simple: >Take a voltmeter and measure voltage between the center >and ring terminals of the glow plug. While glowing, >each should show about 1V. More and you have a bad >glow plug (or connection thereto), the higher the voltage >the worse. 12V indicates a burnt-out plug. Less and >you probably have a problem elsewhere. Look for the >high voltage. Also ensure that the first plug is >getting around 12V to ground. Might be a bit less due >to the 'salt shaker'. > >-- Jim > > > >___ >http://www.okiebenz.com >For new parts see official list sponsor: http://www.buymbparts.com/ >For used parts email [EMAIL PROTECTED] > >To Unsubscribe or change delivery options go to: >http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > >___ >http://www.okiebenz.com >For new parts see official list sponsor: http://www.buymbparts.com/ >For used parts email [EMAIL PROTECTED] > >To Unsubscribe or change delivery options go to: >http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com Loren Faeth ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Replace the second and 4th plugs in order of testing. At 08:30 PM 11/24/2008, you wrote: So I finally tested the glow plugs. The readings, from back to front, were as follows: 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash What does that mean? Time to replace glow plugs? Bob R '77 300D -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Cathey Sent: Saturday, November 22, 2008 10:54 PM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing Diagnosing a series glow plug system is very simple: Take a voltmeter and measure voltage between the center and ring terminals of the glow plug. While glowing, each should show about 1V. More and you have a bad glow plug (or connection thereto), the higher the voltage the worse. 12V indicates a burnt-out plug. Less and you probably have a problem elsewhere. Look for the high voltage. Also ensure that the first plug is getting around 12V to ground. Might be a bit less due to the 'salt shaker'. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com Loren Faeth ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
So I finally tested the glow plugs. The readings, from back to front, were as follows: 1V, 0V, 1V, 2.0V 0.9V with still no glow plug light on the dash What does that mean? Time to replace glow plugs? Bob R '77 300D -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Cathey Sent: Saturday, November 22, 2008 10:54 PM To: Mercedes Discussion List Subject: Re: [MBZ] Glow Plug Testing Diagnosing a series glow plug system is very simple: Take a voltmeter and measure voltage between the center and ring terminals of the glow plug. While glowing, each should show about 1V. More and you have a bad glow plug (or connection thereto), the higher the voltage the worse. 12V indicates a burnt-out plug. Less and you probably have a problem elsewhere. Look for the high voltage. Also ensure that the first plug is getting around 12V to ground. Might be a bit less due to the 'salt shaker'. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Diagnosing a series glow plug system is very simple: Take a voltmeter and measure voltage between the center and ring terminals of the glow plug. While glowing, each should show about 1V. More and you have a bad glow plug (or connection thereto), the higher the voltage the worse. 12V indicates a burnt-out plug. Less and you probably have a problem elsewhere. Look for the high voltage. Also ensure that the first plug is getting around 12V to ground. Might be a bit less due to the 'salt shaker'. -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
On Sat, 22 Nov 2008 21:05:47 -0600 "OK Don" <[EMAIL PROTECTED]> wrote: > This is about the '77 300D, isn't it? Original glow plug type and > circuit? OOPS! The glow plug testing information I just gave is for PARALLEL glow plugs, not series glow plugs. If you remove the plugs and see a circular loop of wire, DO NOT use the advice I just gave! Craig ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
On Sat, 22 Nov 2008 19:29:06 -0700 "Robert Rentfro" <[EMAIL PROTECTED]> wrote: > * Checked continuity from ignition side of 50 amp fuse all the way > to last glow plug.all good. I presume this means you used an ohmmeter and put one probe on the 50 A fuse and the other probe on the glow plug's terminal. Correct? > Will I still have continuity if a glow plug is bad? If you did what I wrote above, yes. Do you have voltage (10 - 12 V) on each of the glow plugs' terminals when the plugs should be glowing? > What should I do next? If you have voltage, pull all of the glow plugs and, one by one, jumper them across the car's battery with some vice-grips and a 12 - 14 gauge wire. Grab the hex of the plug with the vice-grips and connect one end ot the wire to one battery terminal. Touch the vice-grips to the other battery terminal and the wire to the center post on the glow plug. The end of the plug should glow bright orange. Of course, I shouldn't have to say something glowing orange is very hot and can inflict serious burns even after it's stopped glowing orange. The vice-grips grabbing the hex of the glow plug is to keep you from getting burnt. Craig ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
This is about the '77 300D, isn't it? Original glow plug type and circuit? Not if the last glow plug is open (burnt). Measure resistance from it to ground (with it disconnected from the circuit). > > Will I still have continuity if a glow plug is bad? > > What should I do next? -- OK Don, KD5NRO Norman, OK "There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games." - Ernest Hemingway '90 300D (Rattled), '92 300D (Saber), ''97 Ply Grand Voyager (Vincent van-go) ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow plug testing
I don't think that plug is helping initiate combustion very much --- On Sun, Jun 1, 2008 at 2:15 AM, Peter Merle <[EMAIL PROTECTED]> wrote: > It's a Beru plug and glowing at the base of the tip and not the end - see > picture - so when you look down the injector hole you see no glowing tip. I > suspect its not effective anymore as the car suddenly battled to start . I > only visually checked glowplugs as I was about to reinsert the injectors > after having done a compression check. I also changed delivery valves on the > pump from another one as I thought perhaps they were leaking . > > > > http://s285.photobucket.com/albums/ll57/petermerle/?action=view¤t=IMG_3414.jpg > -- OK Don, KD5NRO Norman, OK "There are three kinds of lies: lies, damn lies, and statistics." -Benjamin Disraeli and/or Mark Twain '90 300D (Rattled), '92 300D (Saber), ' '81 240D (Gramps), '97 Ply Grand Voyager (Vincent van-go) ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow plug testing
It's a Beru plug and glowing at the base of the tip and not the end - see picture - so when you look down the injector hole you see no glowing tip. I suspect its not effective anymore as the car suddenly battled to start . I only visually checked glowplugs as I was about to reinsert the injectors after having done a compression check. I also changed delivery valves on the pump from another one as I thought perhaps they were leaking . http://s285.photobucket.com/albums/ll57/petermerle/?action=view¤t=IMG_3414.jpg Peter ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow plug testing
> Are you sure it's drawing only 17 A? If so, where is all that energy > going? ( 17 A x 11 V = 187 W ) The part that's supposed to glow is a lot thinner/less massy than the rest of it. If it's shorted in the body, I suppose eventually the whole thing would get red hot! (If it weren't screwed into the head.) -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow plug testing
On Sat, 31 May 2008 17:32:50 +0200 "Peter Merle" <[EMAIL PROTECTED]> wrote: > I discovered much to my amazement that one of my glow plugs measures OK > ( +- 1 ohm ) and draws 17 A from the battery yet does not glow! Has > anyone had this before ? No! Are you sure it's drawing only 17 A? If so, where is all that energy going? ( 17 A x 11 V = 187 W ) Craig ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow plug testing
The coil is broken inside the "finger" and is shorted to the side. You might find a small hole in the tip where the weld failed. Yeah, don't buy Champion glow plugs, they will do this in about 5000 miles. Peter ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
Just hook the amp meter in series with your cars battery positive connection. No need to buy an expensive DC amps accessory for your VOM. The expensive accessory also has other uses, such as (quickly) checking the output of your alternator, or determining starter current draw. It's a good tool to have for the serious DIY. Speaking of tools, the latest Harbor Freight flyer I got had non-contact thermometers for $10. Great for looking for cooling system problems. Not good for hotter exhaust manifold temps, but good for anything not too much hotter than boiling. -- Jim
Re: [MBZ] Glow Plug Testing
engine. Just disconnect the wire going to each glow plug. Connect a test light to the POSITIVE (+) battery terminal and touch the point of the test light to each glow plug terminal. If the light lights, it's good. If it doesn't, it's bad and needs to be replaced...So, my question is will this work as well as they say? No, that's little more than a continuity check. It'll catch better than half the glow plug failures out there. The common test light uses a 5W or 10W bulb, drawing at most maybe 1A. It'll light indistinguishably for a dead short all the way to a GP with 4x the resistance it ought to have. -- Jim
Re: [MBZ] Glow Plug Testing
In a message dated 11/22/2006 7:43:07 P.M. US Mountain Standard Time, [EMAIL PROTECTED] writes: I went to Sears, Radio Shack, Home Depot and Lowes looking for a multimeter that will test DC current to at least 30A. Autozone was clearing out some 30 amp ad on amp meters for $6 each. Normally they are about $10 each at any auto store, though 60 amp meters are more common. With some #10 wire and a pin adapters, you can really test a glow plug. Just hook the amp meter in series with your cars battery positive connection. No need to buy an expensive DC amps accessory for your VOM. Regards Jim Friesen Phoenix AZ 79 300SD, 264 K miles 98 ML 320, 146 K miles
Re: [MBZ] Glow Plug Testing
There are several failure modes on the pencil type plugs, which actually have a resistance heating element suspended inside the metal shell, attached at the tip and at the electrode in the base. They can indeed melt at the tip. They can fail at the weld in the tip (Champion "12V that really run at 50% duty cycle" GP will do this all the time), the internal resistance element can warp and weld to the sleeve, heating it white hot about half way back, or it can short to the shell too far up and cause the fuse to pop. All will draw current except the unwelded tip failure. Of course, the resistance element can break without shorting, too. The key to determining failure is resistance and current draw, but I use the simple method -- if they look fishy (hot spot half way down the sleeve, for instance) or one is failed open, I replace them all. If one dies, the rest aren't far behind, and on the 603 they are a royal PITA to replace. Peter
Re: [MBZ] Glow Plug Testing
A plug can (on a rare occasion) fail in a "shorted out" mode. The loop of wire that heats with current (glows) usually breaks to an "open circuit" condition. Sometimes more resistance develops in the plug (I don't know how), which reduces the current, keeping the plug from getting as hot as it should. The dead plugs that I've removed from my engines indicate that the wire loop melted - nice round balls on the open ends of the wire. One plug that I saw at my indie's shop had melted such that the end was shorted to the body of the plug, thus producing a short circuit. Current was flowing through the plug, but did not produce heat. A simple continuity test would show the plug as good. A resistance measurement (with sufficient accuracy and resolution) would tell you that it was bad. Measuring the current (again with the sensitivity to discern the differences) would also tell you that the plug is bad. I, however, use the "pull them and look at them, and if in doubt, replace all of them" method. It has worked every time. On 11/22/06, Mike Canfield <[EMAIL PROTECTED]> wrote: So basically it is a test of IF the glow plug will work at all but no indicator of the overall condition of the glowplug. Thanks MarshallMakes perfect sense to me. Mike -- OK Don, KD5NRO Norman, OK "The Americans will always do the right thing... after they've exhausted all the alternatives." Sir Winston Churchill '90 300D, '87 300SDL, '81 240D, '78 450SLC, '97 Ply Grand Voyager
Re: [MBZ] Glow Plug Testing
Not to argue but if the test light lights that seems to me to say that the glow plug is good due to the fact that the heat is created due to pwer being applied to the plug and then shorted to ground. If the light did not light that would indicate a broken circuit and therefore a bad plug. Just another way to measure continuity is all it is. Does continuity indicate a good MBZ glowplug? WOrks for Ford(Navistar) pencil type plugs. Mike(Who is waiting to be corrected by Herr Doktor) Mike - Original Message - From: "Marshall Booth" <[EMAIL PROTECTED]> To: "Mercedes Discussion List" Sent: Wednesday, November 22, 2006 10:11 PM Subject: Re: [MBZ] Glow Plug Testing LarryT wrote: Howdy All, I went to Sears, Radio Shack, Home Depot and Lowes looking for a multimeter that will test DC current to at least 30A. No luck - Sears was sold out and the rest don't carry them. So, I'll order a tester and will be able to test the GP's as Jim C. described. When I got home I did a Google for GP Testing - and got this: "Testing glow plugs is easy and can be done with them still installed in the engine. Just disconnect the wire going to each glow plug. Connect a test light to the POSITIVE (+) battery terminal and touch the point of the test light to each glow plug terminal. If the light lights, it's good. If it doesn't, it's bad and needs to be replaced. Do you replace just the bad one or all of them? My opinion is that if one went bad, then the rest are not too far behind. So I recommend replacing all of them at the same time. I would replace, at the very least, all of the glow plugs on the same side." It came from http://autorepair.about.com/od/enginerelateddiyjobs/l/aa081404c.htm which some may find interesting. So, my question for jim, etc is will this work as well as they say? It looks more like they're testing the engine for a good ground thru the GPs but perhaps it tells if the GPs are good also?? What's the concensus? Is this test as good as testing the DC current? NOT even close! Marshall -- Marshall Booth Ph.D. Ass't Prof. (ret.) Univ of Pittsburgh School of Medicine [EMAIL PROTECTED] ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Glow Plug Testing
LarryT wrote: Howdy All, I went to Sears, Radio Shack, Home Depot and Lowes looking for a multimeter that will test DC current to at least 30A. No luck - Sears was sold out and the rest don't carry them. So, I'll order a tester and will be able to test the GP's as Jim C. described. When I got home I did a Google for GP Testing - and got this: "Testing glow plugs is easy and can be done with them still installed in the engine. Just disconnect the wire going to each glow plug. Connect a test light to the POSITIVE (+) battery terminal and touch the point of the test light to each glow plug terminal. If the light lights, it's good. If it doesn't, it's bad and needs to be replaced. Do you replace just the bad one or all of them? My opinion is that if one went bad, then the rest are not too far behind. So I recommend replacing all of them at the same time. I would replace, at the very least, all of the glow plugs on the same side." It came from http://autorepair.about.com/od/enginerelateddiyjobs/l/aa081404c.htm which some may find interesting. So, my question for jim, etc is will this work as well as they say? It looks more like they're testing the engine for a good ground thru the GPs but perhaps it tells if the GPs are good also?? What's the concensus? Is this test as good as testing the DC current? NOT even close! Marshall -- Marshall Booth Ph.D. Ass't Prof. (ret.) Univ of Pittsburgh School of Medicine [EMAIL PROTECTED]
Re: [MBZ] Glow plug testing procedure and fuse question
J.B. Hebert wrote: Already planning on pulling the manifold. I don't really see any other way to get good access to them. :( Marshall had noted a value of .6 ohms as being nominal. I assume this is for any parallel plug, but I wasn't sure. Regarding the fuse, I'm sure the car has one, but it does not appear to be on the relay as with other MB diesels I've seen. I'll have to look again and see if I can track it down. I knew I had at least one (probably 2) glow plug dead for a while. The car still started OK, but was obviously missing on one more more cylinders until it warmed up for a bit. With another plug gone, the car still starts fine but misses BADLY one at least two cylinders and smokes pretty bad for a minute or two after cold startup. All of the '90s diesels have solid state overload protection for the preglow relay so no longer have a fuse. Marshall -- Marshall Booth (who doesn't respond to unsigned questions) "der Dieseling Doktor" [EMAIL PROTECTED] '87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0 159Kmi, '87 190D 2.5 turbo 234kmi
Re: [MBZ] Glow plug testing procedure and fuse question
Already planning on pulling the manifold. I don't really see any other way to get good access to them. :( Marshall had noted a value of .6 ohms as being nominal. I assume this is for any parallel plug, but I wasn't sure. Regarding the fuse, I'm sure the car has one, but it does not appear to be on the relay as with other MB diesels I've seen. I'll have to look again and see if I can track it down. I knew I had at least one (probably 2) glow plug dead for a while. The car still started OK, but was obviously missing on one more more cylinders until it warmed up for a bit. With another plug gone, the car still starts fine but misses BADLY one at least two cylinders and smokes pretty bad for a minute or two after cold startup. I'll check the plugs tomorrow while I've got the car in the garage to do the brakes. Thanks. J.B. At 04:17 PM 10/7/2005, you wrote: On Fri, Oct 07, 2005 at 12:22:50PM -0400, J.B. Hebert wrote: > Car is a '95 E300D. It appears that I've lost another glow > plug. Since I had been limping by with at least 1 or 2 plugs gone, > this puts me at 2 or 3 plugs gone and the weather is only getting > colder. I can't seem to find the acceptable resistance to ground > email that went around a while ago. Can someone resend it? I should > be able to test the plugs at the relay connector, correct? Also, is > there a GP fuse on later 124 chassis cars like mine? I popped the > cover off my GP relay and didn't see the familiar strip fuse like on > my 123 chassis car. Is it located elsewhere now? I'd like to pick > up some spares before winter if required. The testing procedure I use for any car to test if the glow plug is good or not is simple - measure the resistance through the plug. If the meter thinks that the plug is a dead short AND I haven't blown a fuse, it's fine. If the resistance is higher than a couple of ohms, it's on its way out. If the resistance is infinite, then the plug is definately dead. The only thing that this did not catch was carbon tracing playing with the resistance of one plug in a series plug setup (which you don't have). The plug with the carbon was fine, but the one after it wasn't getting enough juice to light up. Your car should have a strip fuse. Rusty's web page lists them for about a buck and a half. I don't know where it is located on a 124, should probably figure that out. For what it's worth, a six banger will start fine but idle rough on one plug as long as it's not too cold. If you lose two plugs, it'll take forever to start and smoke like a volcano when it does light off. While you're ordering parts, I am pretty sure your 606 has the plugs buried in the intake manifold like my 603s and 601, so you might want to just bite the bullet and yank the intake manifold to make things easier on yourself and your knuckles. Good luck... K -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.10/119 - Release Date: 10/4/2005 J.B. Hebert -- Current Vehicles: '76 Ford Bronco '78 Volvo 262C Bertone V8 '80 Alpina B7 Turbo Coupe '82 Mercedes 300CD (Deceased) '93 GMC Sierra 2500 '95 Mercedes E300D -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.10/119 - Release Date: 10/4/2005
