The BMW UUC Digest Volume 3 : Issue 510 : "text" Format Messages in this Issue: M50B25TU knocking Re: M50B25TU knocking Re: M50B25TU knocking Re: M50B25TU knocking Re: M50B25TU knocking Re: [bimmerheads] Re: M50B25TU knocking Re: M50B25TU knocking Re: M50B25TU knocking Kollidge Kar (?? WOB??) Re: Kollidge Kar (?? WOB??) Re: Kollidge Kar (?? WOB??)
---------------------------------------------------------------------- Date: Fri, 22 Jun 2007 12:50:13 -0700 From: Bob Sutterfield <[EMAIL PROTECTED]> To: [email protected], [EMAIL PROTECTED] Subject: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> My new-to-me 95 525i (146K miles) has a rattle that sounds like preignition. It happens at low-to-mid RPMs (2K-3K) with partial to full throttle, as when accelerating in 2nd gear in city traffic. At full throttle in the upper register (3K-redline) the rattle isn't evident, but maybe it's just harder to hear over the engine music. I ran a couple tanks of 89 octane, then another tank of 89 with BG44K, with no change. Switching to 91 octane reduced the rattle a lot, but there's still a hint persisting. I use only Top Tier(tm) gas, Chevron or Shell. It just had a fresh Inspection-II (post-purchase maintenance baseline) so it has fresh fluids and filters and the plugs looked healthy. Also it easily passed California's tougher smog check. The intake tract looks nearly new, no signs of cracks that could admit unmetered air. The seller kept the car entirely stock, so it should have the stock chip. I'll install a JC or EAT chip eventually but I'd like to make sure the engine is in healthy tune first. Any suggestions? What should I check next? -- Bob Sutterfield 95 525i BMW CCA #169277 Golden Gate Chapter ------------------------------ Date: Fri, 22 Jun 2007 15:56:08 -0400 From: "Gary Derian" <[EMAIL PROTECTED]> To: "Bob Sutterfield" <[EMAIL PROTECTED]>, <[email protected]> Subject: Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> Knock sensors. I think it is common for the M50tu to have failed knock sensors. There are two of them. Gary Derian > My new-to-me 95 525i (146K miles) has a rattle that sounds like > preignition. It happens at low-to-mid RPMs (2K-3K) with partial to > full throttle, as when accelerating in 2nd gear in city traffic. At > full throttle in the upper register (3K-redline) the rattle isn't > evident, but maybe it's just harder to hear over the engine music. I > ran a couple tanks of 89 octane, then another tank of 89 with BG44K, > with no change. Switching to 91 octane reduced the rattle a lot, but > there's still a hint persisting. I use only Top Tier(tm) gas, Chevron > or Shell. > > It just had a fresh Inspection-II (post-purchase maintenance baseline) > so it has fresh fluids and filters and the plugs looked healthy. Also > it easily passed California's tougher smog check. The intake tract > looks nearly new, no signs of cracks that could admit unmetered air. > > The seller kept the car entirely stock, so it should have the stock > chip. I'll install a JC or EAT chip eventually but I'd like to make > sure the engine is in healthy tune first. > > Any suggestions? What should I check next? > -- > Bob Sutterfield > 95 525i > BMW CCA #169277 Golden Gate Chapter > Search the ARCHIVES:http://www.mail-archive.com/[email protected] > > > __________________________________________________________________________ > In memory of Michel Potheau - friend, enthusiast, founder of the BMW CCA. > > UUC Motorwerks - BMW Performance Fine-tuning and home of the Ultimate > Short Shifter - accept no substitutes! > 908-874-9092 . http://www.uucmotorwerks.com ------------------------------ Date: Fri, 22 Jun 2007 13:37:53 -0700 From: Bob Sutterfield <[EMAIL PROTECTED]> To: [email protected], [EMAIL PROTECTED] Subject: Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> Gary Derian <[EMAIL PROTECTED]> wrote: > Knock sensors. I think it is common for the M50tu to have > failed knock sensors. There are two of them. Yeah, I was surprised to hear (what I thought sounded like) knocking, but this is my first car with those newfangled knock sensor thingies so I don't know what to expect of them. The car is so new that its Bentley hasn't arrived yet. It's not throwing any codes, and the Check Engine light is off. Is there a simple test? B Barry <[EMAIL PROTECTED]> wrote: > Might it be Vanos or injector noise? I need to listen to a car with Vanos problems and see if the sound is similar. This is far louder than the injector noise I remember from listening to an M20 or M30 at idle. Jim Bassett <[EMAIL PROTECTED]> wrote: > - Avoid low-RPM, high-load situations; this has been the most effective > solution for me, although my avoidance-factor is less than 100% :-); I understand this, but mid-throttle 2K-3K acceleration isn't usually low-RPM or high-load enough to set an engine knocking. Thus I wondered if something was wrong other than technique. > Also, make sure you have new knock sensors, but I'm not sure that will fix > the issue. It's really more due to the sorry excuse for gas we have :-) OK, that's two votes for the knock sensors. Scott Miller <[EMAIL PROTECTED]> wrote: > Charlotte's '93 525iA pinging stopped after we had > the knock-knock sensors replaced... it is possible > that it was not bad knock sensors. All right, I'll look into the knock sensors as soon as my Bentley arrives. > 1. The owner's manual for our '93 specifies 91 octane gas, not 89. > I don't know if the '95 is the same, but I bet it is. The 95 owner's manual chart says 89 AKI or 95 RON, with a footnote "Unleaded gasoline with an AKI of 89 is recommended. Unleaded gasolines of 87 AKI or 91 RON may also be used due to BMW's anti-knock-control [SIC]. In this case, a slight influence on engine efficiency can be expected." > 2. If the VANOS were not working properly, there could be times > when the timing is more advanced than it is supposed to be, which > could also result in some pinging. But usually when the VANOS fails, > it makes that marbles in a can sound, so you'd probably know > if this were the case. That's what I was thinking (and hoping) too. Thanks for all the suggestions! ------------------------------ Date: Fri, 22 Jun 2007 13:49:24 -0700 (PDT) From: Tammer Farid <[EMAIL PROTECTED]> To: [email protected] Subject: Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> --- Bob Sutterfield <[EMAIL PROTECTED]> wrote: > I need to listen to a car with Vanos problems and see if > the sound is > similar. This is far louder than the injector noise I > remember from > listening to an M20 or M30 at idle. Having both an M30 and an M50, I can assure you the injectors of the latter should be much quieter than those of the former. Here's a question for you, Bob: Does the car seem down on power? As in, it revs willingly but the pull isn't quite what you think it should be? -tammer ____________________________________________________________________________________ Get the free Yahoo! toolbar and rest assured with the added security of spyware protection. http://new.toolbar.yahoo.com/toolbar/features/norton/index.php ------------------------------ Date: Fri, 22 Jun 2007 16:44:59 -0400 From: "Gary Derian" <[EMAIL PROTECTED]> To: "Bob Sutterfield" <[EMAIL PROTECTED]>, <[email protected]>, <[EMAIL PROTECTED]> Subject: Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> In the old days, one would hit the engine with a hammer while watching the timing mark with a timing light. Its rather difficult to attach a timing light to an M50. Since your noise diminished greatly with higher octane fuel, I'd strongly suspect the knock sensors, not the VaNoS. Try a few gallons of unleaded racing fuel and see if the noise disappears completely. Mid throttle and mid rpm is prime knock territory as timing is advanced to maximize fuel economy, and there is ample time for knock to develop at the lower rpm. Gary Derian > Check Engine light is off. Is there a simple test? ------------------------------ Date: Fri, 22 Jun 2007 13:53:37 -0700 (PDT) From: "Jim Bassett" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Cc: [email protected] Subject: Re: [bimmerheads] Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> On Fri, June 22, 2007 1:37 pm, Bob Sutterfield wrote: > Jim Bassett <[EMAIL PROTECTED]> wrote: >> - Avoid low-RPM, high-load situations; this has been the most effective >> solution for me, although my avoidance-factor is less than 100% :-); > > I understand this, but mid-throttle 2K-3K acceleration isn't usually > low-RPM or high-load enough to set an engine knocking. But that's the point, it IS when running CA gas. > OK, that's two votes for the knock sensors. Well, one-and-a-half :-) It was more of an afterthought than thinking it was the cause of the "problem". Replacing them isn't a bad idea (they are a bit of a PITA to do, however), but you will still experience the knocking in certain situations on CA gas. Jim Bassett ------------------------------ Date: Fri, 22 Jun 2007 13:09:43 -0700 (PDT) From: "Jim Bassett" <[EMAIL PROTECTED]> To: [email protected] Cc: [EMAIL PROTECTED] Subject: Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> On Fri, June 22, 2007 12:50 pm, Bob Sutterfield wrote: > Any suggestions? What should I check next? Welcome to California, home of crap-tacular gasoline! :-) Seriously, our "91" isn't really. I guess you could: - Add in a couple of gallons of 100 to each tank-full to raise the octane level (race car gets this treatment at the track, and no issues); not sure how practical this is, however; - Avoid low-RPM, high-load situations; this has been the most effective solution for me, although my avoidance-factor is less than 100% :-); - Move to a state that has *real* gasoline :-) Also, make sure you have new knock sensors, but I'm not sure that will fix the issue. It's really more due to the sorry excuse for gas we have :-) Cheers, Jim Bassett 1998 M3/4 1993 325is #44 JP ------------------------------ Date: Fri, 22 Jun 2007 20:21:17 +0000 From: [EMAIL PROTECTED] To: [email protected] Subject: Re: M50B25TU knocking Message-ID: <[EMAIL PROTECTED]> Bob, we had a similar pinging problem with Charlotte's '93 525iA (currently about 130K miles). The pinging stopped after we had the knock-knock sensors replaced. We had this done at the same time that the head was off to replace a blown head gasket, so the job was a lot easier (so I'm told) than if you have to do it with everything still on the engine. Of course, we also had a complete valve job at the same time, so it is possible that it was not bad knock sensors. You pays your money and you takes your chances. Two other things to check: 1. The owner's manual for our '93 specifies 91 octane gas, not 89. I don't know if the '95 is the same, but I bet it is. 2. If the VANOS were not working properly, there could be times when the timing is more advanced than it is supposed to be, which could also result in some pinging. But usually when the VANOS fails, it makes that marbles in a can sound, so you'd probably know if this were the case. Scott Miller GGC BMW CCA ----- Original Message ----- From: "Bob Sutterfield" <[EMAIL PROTECTED]> To: <[email protected]>; <[EMAIL PROTECTED]> Sent: Friday, June 22, 2007 12:50 PM Subject: [bimmerheads] M50B25TU knocking > My new-to-me 95 525i (146K miles) has a rattle that sounds like > preignition. It happens at low-to-mid RPMs (2K-3K) with partial to > full throttle, as when accelerating in 2nd gear in city traffic. At > full throttle in the upper register (3K-redline) the rattle isn't > evident, but maybe it's just harder to hear over the engine music. I > ran a couple tanks of 89 octane, then another tank of 89 with BG44K, > with no change. Switching to 91 octane reduced the rattle a lot, but > there's still a hint persisting. I use only Top Tier(tm) gas, Chevron > or Shell. > > It just had a fresh Inspection-II (post-purchase maintenance baseline) > so it has fresh fluids and filters and the plugs looked healthy. Also > it easily passed California's tougher smog check. The intake tract > looks nearly new, no signs of cracks that could admit unmetered air. > > The seller kept the car entirely stock, so it should have the stock > chip. I'll install a JC or EAT chip eventually but I'd like to make > sure the engine is in healthy tune first. > > Any suggestions? What should I check next? > -- > Bob Sutterfield > 95 525i > BMW CCA #169277 Golden Gate Chapter ------------------------------ Date: Sat, 23 Jun 2007 06:28:45 -0500 From: "Bill Proud" <[EMAIL PROTECTED]> To: "Uucdigest" <[email protected]>, "Senior Digest" <[EMAIL PROTECTED]> Subject: Kollidge Kar (?? WOB??) Message-ID: <[EMAIL PROTECTED]> Any of you'se geeks need a nice clean '85 BMW 325e ? Perfek for sending kidz off to Kollidge ...prolly THE most reliable small BMW since the 2002 2-door , white , sunroof, manual trans and currently has 'bling-bling' wheels ......but owner has the original wheels too . Havent been to see it yet , but it looks good in the one photo I've seen ...at least it's sheen and cliny . Folkz I know who've had them claim up to low-thirties MPG driven normally . They make good beginning race-cars too ....lotsa torque outta corners . Located 70 mls south of Nashville (Nose-singing capital of the World ) ..where salt doesnt grow on winter roads . Easy in and out of the airport .....freeways to everywhere !! If you express interest privately I'll go look at it ........yours for circa $2.2K depending on how much messing about I have to do and on what it really looks like when I get close to it Bill Proud , 37 yrs messing with BMWs .. ------------------------------ Date: Sat, 23 Jun 2007 09:23:14 -0700 From: Bob Sutterfield <[EMAIL PROTECTED]> To: [email protected] Cc: "Senior Digest" <[EMAIL PROTECTED]> Subject: Re: Kollidge Kar (?? WOB??) Message-ID: <[EMAIL PROTECTED]> Great car for a new driver too. In a 325e [s]he won't be the first to the scene of the accident. ------------------------------ Date: Sat, 23 Jun 2007 12:40:50 -0700 From: "jchasd" <[EMAIL PROTECTED]> To: "'Bob Sutterfield'" <[EMAIL PROTECTED]>, <[email protected]> Cc: "'Senior Digest'" <[EMAIL PROTECTED]> Subject: Re: Kollidge Kar (?? WOB??) Message-ID: <[EMAIL PROTECTED]> Bought '86 325e for my daughter in 2002. We redid the brakes together and got it in shape for the 2500 mile drive. Made it in two days, sharing the driving. Solid car for her 3rd and 4th school years. 5-speed was the perfect choice. None of her friends could drive a stick, so she never had to lend it to anyone. She graduated, sold the car. She now lives in New York City where she is teaching her boyfriend to drive a stick (his new Aston Martin). Chas '83 633CSi '85 528e '01 740i Sport '03 525i -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bob Sutterfield Sent: Saturday, 23 June, 2007 09:23 To: [email protected] Cc: Senior Digest Subject: Re: [UUC] Kollidge Kar (?? WOB??) Great car for a new driver too. In a 325e [s]he won't be the first to the scene of the accident. Search the ARCHIVES:http://www.mail-archive.com/[email protected] __________________________________________________________________________ In memory of Michel Potheau - friend, enthusiast, founder of the BMW CCA. UUC Motorwerks - BMW Performance Fine-tuning and home of the Ultimate Short Shifter - accept no substitutes! 908-874-9092 . http://www.uucmotorwerks.com ------------------------------ End of [bmwuucdigest] digest(11 messages) **********
