Re: [MBZ] Testing OM603 head for cracks
Aye! On March 1, 2014 10:30:53 PM EST, Mountain Man maontin@gmail.com wrote: Max wrote: Dieselvolk, Max is back!! mao -- Max Dillon Charleston, SC ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Max Welcome back. I was just wondering what happened to you a few days ago. I have never pressure checked a head, so I don't know the procedure. 15 psi sounds about right to me, so a wood plate may work, especially if you have a non-porous wood like birch or had maple. I'd not worry too much about sealing the valves, the point would be to look for bubbles coming out of unexpected places. I made my own form of cyl leakdown test years ago. the question was not is there a leak,? but Is there any leak that is different for one cyl? for that test. I used full pressure from the air compressor for that. I think you could tell bubbles coming from a valve vs bubbles coming from a coolant passage whiile underwater. You might ask around auto machine shops to see if anyone can test the head and is willing to let you watch. Around here, many will let you watch. HTH Dieselvolk, A new chapter has begun in the never-ending saga of the head replacement on my '87 wagon. I finally removed the first replacement head, #20 casting, because of a problem with a hydraulic lifter bore and because the cooling system would remain pressurized overnight, following the rare occasions when I drove the car. This head was supposedly tested for cracks by our best local machine shop. I was really hoping to find evidence that the head gasket had failed, but to my inexperienced eye, it looks fine. So I'm thinking of ways to test the head for cracks. If there is a crack which allows exhaust gas into the cooling system, then if I pressurized the exhaust manifold and immersed the head in water, bubbles from any cooling passage would indicate a crack, no? How much pressure will the exhaust valves hold? Any clever ideas for sealing them closed? I was thinking of using wax, but the melting point is too low. The factory test requires a special plate bolted to the block side of the head, and then the cooling passages are pressurized to 15 psi and the head is immersed in water heated to 80 degrees C. I've also thought about fabricating my own plate from wood. -- Max Dillon Charleston, SC ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Did you re-use the headbolts when replacing that head? Not a good idea as they usually fail to keep the head gasket sealed. The other symptom of a cracked head is excessive water smoke when cold and coolant loss, although if you have a pressurized cooling system you should be able have someone check for exhaust gas in the coolant, Peter ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Head bolts were new. Only drove the car a few hundred miles with the 20 head. Cooling system started leaking from a hose as well, so I can't tell if it was burning coolant, but I think not as all the parts of the head exposed to combustion have equal build up of carbon. In other words, none look steam cleaned. On March 2, 2014 10:37:20 AM EST, Peter Frederick psf...@earthlink.net wrote: Did you re-use the headbolts when replacing that head? Not a good idea as they usually fail to keep the head gasket sealed. The other symptom of a cracked head is excessive water smoke when cold and coolant loss, although if you have a pressurized cooling system you should be able have someone check for exhaust gas in the coolant, Peter ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com -- Max Dillon Charleston, SC ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Yeah, that shiny piston head is a clue! Any cylinder head repair facility can check for cracks, but you can do the air hose test yoursefl -- use a parts blower nozzle on an air hose and blow laterally across the top of the combustion chambers. Cracks usually cause a shriek, and in some cases are clearly visible. The bad ones are between the valves and between the valves and the pre- chamber. Not repairable so far as I know. Peter ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Nothing visible with the valves still installed. I'll clean off the carbon... On March 2, 2014 4:08:32 PM EST, Peter Frederick psf...@earthlink.net wrote: Yeah, that shiny piston head is a clue! Any cylinder head repair facility can check for cracks, but you can do the air hose test yoursefl -- use a parts blower nozzle on an air hose and blow laterally across the top of the combustion chambers. Cracks usually cause a shriek, and in some cases are clearly visible. The bad ones are between the valves and between the valves and the pre- chamber. Not repairable so far as I know. Peter -- Max Dillon Charleston, SC ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Yeah, that shiny piston head is a clue! Any cylinder head repair facility can check for cracks, but you can do the air hose test yoursefl -- use a parts blower nozzle on an air hose and blow laterally across the top of the combustion chambers. Cracks usually cause a shriek, and in some cases are clearly visible. The bad ones are between the valves and between the valves and the pre-chamber. Not repairable so far as I know. Peter I have a 14 head that shows no cracks, but leaks oil into #1 AFTER being refurb. I suspect the crack is deep in the intake valve passages. I suspect Max's head also has a crack deep inside where it is not visible. On Iron heads, the usual cracks were as Peter describes, between the valves and between one valve and the prechamber. In every case, these were clearly visible, and these cracks were allowed if less than 10 MM long. (on iron heads) ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Oil leaks into #1 is a head gasket failure for the most part -- later heads and later gaskets have a better oil passage there (it's the one going to the cam, I think). Very common failure point, and warpage could make the head fail to seal there without any cracks. The cracks that cause all the trouble are in the combustion chamber and extend to the cooling passages, are hard to find, and impossible to repair -- I suspect because they propagate too far to weld up and probably welding just causes more to form adjacent. No one has repaired on that I know of. Peter ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Oil leaks into #1 is a head gasket failure for the most part -- later heads and later gaskets have a better oil passage there (it's the one going to the cam, I think). Very common failure point, and warpage could make the head fail to seal there without any cracks. The cracks that cause all the trouble are in the combustion chamber and extend to the cooling passages, are hard to find, and impossible to repair -- I suspect because they propagate too far to weld up and probably welding just causes more to form adjacent. No one has repaired on that I know of. Peter Head surface was flat, new head gasket, new headbolts. Leaked oil into #1 before (original Head gasket blown, probably due to excess oil in cyl) Leaks oil the same into #1 after going through the head shop. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
I suppose it could be a bad block surface, but sure does sound like a bad head. That oil passage is a weak spot, and there is no reason why it wouldn't crack through. New heads are expensive. Peter ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
[MBZ] Testing OM603 head for cracks
Dieselvolk, A new chapter has begun in the never-ending saga of the head replacement on my '87 wagon. I finally removed the first replacement head, #20 casting, because of a problem with a hydraulic lifter bore and because the cooling system would remain pressurized overnight, following the rare occasions when I drove the car. This head was supposedly tested for cracks by our best local machine shop. I was really hoping to find evidence that the head gasket had failed, but to my inexperienced eye, it looks fine. So I'm thinking of ways to test the head for cracks. If there is a crack which allows exhaust gas into the cooling system, then if I pressurized the exhaust manifold and immersed the head in water, bubbles from any cooling passage would indicate a crack, no? How much pressure will the exhaust valves hold? Any clever ideas for sealing them closed? I was thinking of using wax, but the melting point is too low. The factory test requires a special plate bolted to the block side of the head, and then the cooling passages are pressurized to 15 psi and the head is immersed in water heated to 80 degrees C. I've also thought about fabricating my own plate from wood. -- Max Dillon Charleston, SC ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
From:Max DillonSent:Saturday, March 1, 2014 8:18 PMTo:Mercedes Discussion ListReply To:Mercedes Discussion ListSubject:[MBZ] Testing OM603 head for cracksWho's the new guy? :-) Welcome back Max. Rick Sent from my BlackBerry 10 smartphone. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Thanks Rick, I'm looking forward to being part of this fold again. Also REALLY looking forward to getting my wagon back on the road. On March 1, 2014 9:23:26 PM EST, Rick Knoble rickkno...@hotmail.com wrote: Who's the new guy? :-) Welcome back Max. -- Max Dillon Charleston, SC ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing OM603 head for cracks
Max wrote: Dieselvolk, Max is back!! mao ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
