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Supreme Being
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Plugs have 10k on them. I inspected #6, the one that had a misfire on it and it was visually fine. I als switched the coil of #6 with one next to it and still the problem and no codes still. The low rpm studder continues!
Barry 214-215-7383
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Supreme Being
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Last Login: 9/21/2008 9:12:17 AM
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| I was thinking of getting one cam sensor and move it from side to side to see if the problem changes. MAF replacement; I have heard that there are either Rover or VM MAF's that are identical and lower cost; does anyone have part numbers for them that work on a 2000 540? Crank sensor; never heard of it die'ing. Note that this is just a low rpm stumble. Could a faulty Crank sensor cause this?
Barry 214-215-7383
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Supreme Being
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I had a 1998 540i-6spd and it had similar issues. This car only had one cam sensor (not dual Vanos) and it had that low rpm stutter as soon as I bought it. It went away after the sensor was replaced but came back later. Misfire on Peake. Leaking valve cover gasket was allowing oil to get into spark plug wells and they were soaked. Replace gasket + plugs and it seemed OK right up until I sold it at 129K miles.
Terry Fair - www.vorshlag.com & www.ast-usa.com
"Alpha" E36-LS1 (XPrepared/G Class "No Class") '97 M3 (STU/F Class), '91 318is (STS/C Class)
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Supreme Being
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Last Login: 9/23/2008 11:22:09 PM
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bseidner (5/22/2008)
I was thinking of getting one cam sensor and move it from side to side to see if the problem changes. MAF replacement; I have heard that there are either Rover or VM MAF's that are identical and lower cost; does anyone have part numbers for them that work on a 2000 540? Crank sensor; never heard of it die'ing. Note that this is just a low rpm stumble. Could a faulty Crank sensor cause this? Sorry, I mistyped. Scratch the crank position sensor. If it was bad the car wouldn't start. The 540 shoudl have 2 cam position sensors (one for the intake cam on each bank). Pointless to buy one and move it around (unless you are into S&M in which case go right ahead- it was more cost effective to go ahead and do it once and be done with it IMO). There are some VW MAFs that fit the M5. Not sure if they fit the M5. Cross reference the PNs for 540 and M5 MAFs. Search m5board for the VW part numbers...or buy an MAF from DavidS for about $115. I am pretty sure your problems will go away with replacing both cam position sensors, MAFs and both precat O2 sensors. They are all supposed to last 100k miles, but they don't. Last time I am going to suggest these things. Good luck.
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Supreme Being
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| Thanks Bruce. Good advice of course. I am off to buy. Quick questions: I have line wrenches and plan to use them to replace the pre-cat sensors. Do they need to be heated (torch) to remove? Maybe that is a post-cat problem; I just do not know. Also, have you heard of a Ignition coil causing this as well? I have read (only a few) posts that show others having a similar symptom and they bought one coil and moved it around the engine until the problem resolved. Seems like I should replace all the parts listed anyway; per your note. But if these replacements do not resolve this issue, is that a reasonable next step?
Barry 214-215-7383
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Supreme Being
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| I wouldn't replace ALL of the items. IF you are going to shotgun replace why not start with cam sensors then MAF but see if the problem gets fixed after each part replacement? Before I would spend $1k on parts you don't know are bad take it to a mechanic. There's no way both cam sens, MAF and all 4 O2 are bad. Also order the parts online you will save over the dealer, sometimes the savings is 35-40%.
Jeron
BMW / PCA / Apex HPDE Instructor
97 M3/4 Byzanz/Magma; 2001 330i Silver/Gray; 97 R1100RT; 91 F-150 5.8l
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Supreme Being
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This week I replaced one then both CAM sensors and the problem still exists. I also "borrowed" a working MAF and the problem still exists. I also cannot find a vacuum leak. Next to replace is the pre-cat O2 sensors. I am guessing they are in the exhaust manifold. I went to Classic and found them to be $218 each; Pelican Parts sells two of them for $125; both are Bosch. So they are on order. This weekend I plan to replace the valve cover gaskets (because I was planning to anyway). No oil in the wells but a good inspection cannot be a bad thing.
Any other suggestions??
Barry 214-215-7383
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Supreme Being
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| Just throwing this out there......I have been following this string.....and the individual that posted about your shotgun method of tackling this problem is right. How much money is the breaking point for you? Most shops generally charge for diagnostic if you are not letting them fix it and not if you do(most but not all). But with that said a qualified shop could probably pin this down in an hour or two of diagnostic. FYI Cam and Crank sensors will set faults when they are failing. They are not silent when the go off on their own. If you are getting misfires at 6 only I would look hard at 6 and what affects it. This can also be internal which may not be fixable by strapping parts externally. Additionally a Mass Air Sensor would not affect just one cylinder and generally when going will set fuel trim and multiplicative deviation faults across both banks. If O2 sensors are failing they will set faults describing that. Doubtful that yours needs O2 sensors with only 70k on it. In fact in 8 years I don't think we have put an O2 sensor on a V8 car with less than 100k on it. Valve cover gaskets if needed are a good place to start since you get a look inside. But in my opinion(not having ever seen your car it is only a guess) and judging by the miles and issues you describe.......if you want to shotgun parts at this car then you need to replace the vacuume transducer and all of the intake seals and gaskets. It is time in miles for these items even if this isn't the issue. Good luck and watch your aim!
Trent Cole
Lone Star Bavarian, inc
3800 West Vickery Blvd. Ft. Worth, Tx 76107
817-732-4888
www.bmwfxr.com
BMW CCA Tech Advisor, Lone Star Chapter
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Supreme Being
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Last Login: 9/21/2008 9:12:17 AM
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Trent, thanks for the advice. Always great having an expert on the team. Can you help me understand what a vacuume transducer ? Did you mean the CCV; Crankcase Vent? or is this something else? Transducer sounds like a electrical sensor.
Barry 214-215-7383
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