.
Last edited by SGs54MC; 06-27-2013 at 02:54 PM.
Were the misfires occurring on only one cylinder bank or both?
Also, could you clarify on your RPM range?
idle-2500 = random misfires. Meaning 2500-redline = working normal?
Lucky Me! I get to maintain the best Driving ///Machine and Flying Machine in the world.
Before spending the hundreds of dollars on replacing O2s, I would find someone with a MODUS, SOLUS scanner from snapon or any other type of graphing scanner and watch for erroneous faults or strange readings. If nothing comes of that I would check your fuel pressure under 2500 and over 2500.
Lucky Me! I get to maintain the best Driving ///Machine and Flying Machine in the world.
What kind of coils are you running?
There was an SB for Bremi coils requiring complete replacement.
BMW Special Tools: RTAB, FCAB, Shim Kit & Tool, Cam Holder, and Flywheel Lock
i had the same prob where id get the cel mad random for fuel adaption or randomn misfire every 6 months but the car always ran fine. then 2 months ago the car was misfiing outta blue and wouldnt run eventually. replaced three coils and all is well. i dont think switchin it around helps too much as i think when the coils act kinda funny its hard for the ecu to detect exactly where its coming from. mine was saying cyl 2 and 4(they fire toghehter) so i replaced coils 234 just to be safe and all was well.
just re read it if you reversed the coil order that rreally wont help you as those cyls fire at the same time so when one is of the other "fine" cyl is likely to be affected possibly throwing it off and miisfire possibly detected there.
this is the logic i used worked for me but i might have got lucky lol
Last edited by turbospool; 11-11-2010 at 12:04 PM. Reason: Automerged Doublepost
The coils might be a good cheap diagnostic, but at some point I'd be ready to pay a tech the $80 or $150 to diagnose the problem.
With a scan tool they can track a lot of stuff that's going on real-time...
Since it's RPM dependent I would consider the VANOS, but the coils have been a constant PITA on these cars too.
I have an intermittent miss, or at least it feels like I do, but it's not thowing a mis-fire code so I don't know what the deal is-
-Aaron
2004 M3 - Coupe, 6spd, Silver Grey on Black
| RAC RG63, PSS, ZCP Brakes, aFe, SS (V1, Res. X-pipe, Street Muffler), Epic Alpha-N, 319whp |
2006 Jetta TDI/DSG, Pkg 2, Silver on Black - Sold
2004 M3 SMG - Silver Grey on Black, Convertible - RIP
1995 525I 5spd - Black on Black -Sold
2004 X3 3.0i AT- Blue on Tan - For the wife....
Multiple/random misfires often indicate a simple bad ground connection. Have you looked into this?
-Peter
Current toy: none
Past cars: 88 M3, 99 M3 x2, 04 M3, 91 NSX, 06 S2000, 01 911TT, 06 Exige, 00 NSX, 04 GT3
I thought the same but he said he'd switch the coils with different cyl. and same result. i agree if the oe coils are the bremi, i'd switch to the bosch. if they are the bosch and are recent coils then i'd concentrate on the O2s. get someone with the autoingenuity software to see what codes are stored OR take it to the dealer and spend the $100+ so they can tell you for sure what they think is the cure.
ESS 625RAGE AGAINST THE MACHINE
Take it an auto parts store that can scan the codes, it can help narrow it down. Also when was that las time you replaced the Fuel filter?
Mods: Shark Injector, Sprint Booster, AFE Intake Scoop, AFE Intake Elbow, K&N pannel Filter, Eibach PRO-PLUS, PRO-KIT Springs & ANTI-ROLL-KIT Sway Bars, Bilstien HD Shocks and Struts, Powerflex RTAB, UUC Stanless Steel Break lines, UUC Shock mount Kit, Drilled and Slotted Front & Rear Breaks, *LED Angel Eyes, HID Driving Light, Front and Side Blackout grills, Smoked Side turn signals, LED Side Turn Signals, Painted Front Reflectors, Interior LED Lights, VMR VB3 18" staggered CLS Style Wheels,
last time i replaced coils as a preventative maintenance, my car didn't like Bosch and Bosch plugs..
installed Bremi coils and NGK plugs and problems solved...
however it sounds you might have some issues with Vanos. maybe bolts are messed up, maybe gear.
when was the last Valve adjustment?
"Only after disaster can we be resurrected.", Tyler Durden, Fight Club.
------------------
CURRENT
2002 M3 conv - '07; 2006 k1200s - '09; 1998 M3 CB coupe - '10; 2004 X3 - '13
not a genious here, but have done a lot of auto work and had some training. have to agree with you, about fuel/air mix. randome misfires scream lean mixture...... if you can get a vacuum haned pump, attach it to the EGR vaolve and see if it is hoolding.
Last edited by Boomer M3; 11-25-2010 at 12:11 AM. Reason: add to my orig thot
I would suggest just pulling the O2 sensors out to see how dirty they are. Sometimes a wire brush to clean them off does it just fine. Replacements is at 100k by the book, but if you do alot of city driving, they can get "dirty" quicker
I just went to the TIS and followed the trbl shooting guide for misfires, poor ops under full load, poor ops at idle, poor ops when cold, poor ops when warm.... you get the idea. all these send you to a fuel pressure check. its the only thing suggested.....
ops= operation
No, I agree with your logic on the fuel demand.
Damn, now I'm hooked.
I believe these cars have an idle air control valve. Might want to check that. if its staying wide open for some reason you will probably get a lean misfire.... particularly at lower power settings.
If the EGR is vacuum operated, you can use a hand-held vac pump and gauge to see if it holds vac. The diaphrams in all vac motors, switches, etc get brittle after lots of heat which the EGR deals with all the time.
You can use a bottle of propane... I think it is propane that is used for soldering copper water pipes.... to test for vac leaks. Put the control valve on the bottle after removing the tip from it. Get a piece of vacuum line (3 ft or so) and stick on the end after removing the tip. KEEPING THE BOTTLE UPRIGHT, turn on just enough flow to be able to feel it as a slight breeze coming out of the end of the hose. Run that end along the different vac lines and components WHILE THE ENGINE IS RUNNING. If a leak is encounterred, a slight rise in RPMs will be heard. WARNING! I probably don't have to tell you that this operation could be a bit dangerous if not performed carefully. Well ventalated area etc. You must have 2 people! Have someone holding the bottle and watching that the hose doesn't get into something spinning or onto something HOT.
I will take another look at the TIS..... might have to dig out my old school books!~ lol!
Last edited by Boomer M3; 01-14-2011 at 12:55 PM.
My friend's brother owns a 2008 645. He was experiencing the same exact issues with misfires, etc as you have explained. He traced the problem to a crankshaft position sensor. I checked Bavauto.com and they list the part number as Part # : 12 14 1 744 492 for the 2001 M3. Price is $95. I hope this is the culprit. Good luck.
Yeah, I am always a little reluctant to pass that one on. But it pulled my a** out of the hotseat a few times. Vehicles used to have a lot more vacuum lines and components than they do now. I added the part about having someone else hold the bottle and mind the hose, as that is the only problem I have ever had with it. With the engine running there is usually enough air movng to keep the propane from accumulating, but that sometimes makes it more difficult because the gas gets blown off target.
Check if you have any holes/cracks in the airbox or tubing to intake manifold. Sounds like the symptoms of two cars I worked on.
[2.25" Magnaflow][3.38 LSD][GC Track/School][3.5" HFM][Cosmos V2 + Tuning][UUC Sway Bars][UUC Subframe Bushings, RTAB, RSM w/ Plates, Trans. Mounts][X-Brace][Brembos]
Hey did you ever figure this out?
Here's what I've done to mine:
Coils
Plugs
all filters
O2 sensors
I experience the same issues as you.
Cold start cycle = fine
Warm start cycle = random misfires. It does not happen if I turn off the engine and restart it, only if the vehicle has been sitting for longer periods (like 10minutes or more) and I restart it again. Keep in mind that this only happens during te "warm-up" warm start cycle, if this make sense. Once the cycle is complete, it idles like a dream (or cream?)
Car otherwise runs normally and no loss of power. My BAV tool doesn't indicate anything out of the ordinary when I scroll through the logs in "real-time." No CEL light, no hidden codes for anything. I'm leaning towards a bad TPS (the one under the intake manifold)
Last edited by BMW Loe; 03-25-2011 at 09:38 PM.
-Loe- 2004 M3/2000 328Ci (some mods)
Seems like we're a good way into making up a checklist for the S54... My little intermittent miss is bugging the hell out of me!
-Aaron
2004 M3 - Coupe, 6spd, Silver Grey on Black
| RAC RG63, PSS, ZCP Brakes, aFe, SS (V1, Res. X-pipe, Street Muffler), Epic Alpha-N, 319whp |
2006 Jetta TDI/DSG, Pkg 2, Silver on Black - Sold
2004 M3 SMG - Silver Grey on Black, Convertible - RIP
1995 525I 5spd - Black on Black -Sold
2004 X3 3.0i AT- Blue on Tan - For the wife....
Have looked to see which coil packs you have?Originally Posted by abakos
Bremi are known to have been a problem. The Bosch packs are the ones BMW is replacing under a recall letter
Mods: Shark Injector, Sprint Booster, AFE Intake Scoop, AFE Intake Elbow, K&N pannel Filter, Eibach PRO-PLUS, PRO-KIT Springs & ANTI-ROLL-KIT Sway Bars, Bilstien HD Shocks and Struts, Powerflex RTAB, UUC Stanless Steel Break lines, UUC Shock mount Kit, Drilled and Slotted Front & Rear Breaks, *LED Angel Eyes, HID Driving Light, Front and Side Blackout grills, Smoked Side turn signals, LED Side Turn Signals, Painted Front Reflectors, Interior LED Lights, VMR VB3 18" staggered CLS Style Wheels,
replace the MAF-just bc its "clean" doesnt mean its any good...would also explain why cold start your fine...
did anyone ever figure this out? I am having similar issues:
http://www.m3forum.net/m3forum/showthread.php?t=406481
-Aaron
2004 M3 - Coupe, 6spd, Silver Grey on Black
| RAC RG63, PSS, ZCP Brakes, aFe, SS (V1, Res. X-pipe, Street Muffler), Epic Alpha-N, 319whp |
2006 Jetta TDI/DSG, Pkg 2, Silver on Black - Sold
2004 M3 SMG - Silver Grey on Black, Convertible - RIP
1995 525I 5spd - Black on Black -Sold
2004 X3 3.0i AT- Blue on Tan - For the wife....
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