I have been chasing the same issue for the past two months about the car never idling above 500 acting weird at a specific temp etc. Today I was testing some voltages and sensors when I found what was supposed to be a 5V reference signal is not 5V but is instead 6.4V. How close to 5V is it supposed to be? If I understand my reading correctly then the DME has an internal component failure? I just went through the DME and re-soldered it and it did lighten the issue effect but some component may have given up already..
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04 BMW 325xi 143k
The Fun car:
94' BMW 740i 308k miles
Fresh 72k mile engine with all new seals. True E34 Manual Trans Engine Harness. 6spd Transmission Swap, Getrag 420G. RHD LW Single Mass Flywheel. E39 M5 Clutch. E39 M5 Shifter. Factory Car Phone. Factory 6CD Changer. Factory Electric Sunshade. Not So Factory Factory Electric/Heated Rear Seats. E38 Heater Valves. E43 M5 calipers/brakes
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Get another 404 DME, they're dime a dozen.
I have a feeling that is the cause of all my issues, it is perfectly fine with no adaptations but starts to act up when it adapts. My electrical engineer friend doesn't think the DME is bad but it is the only part that hasn't been replaced or verified working.
New Daily:
2011 Audi A6 Avant 3.0T prestige. 1 of 368
----FOR SALE-----
04 BMW 325xi 143k
The Fun car:
94' BMW 740i 308k miles
Fresh 72k mile engine with all new seals. True E34 Manual Trans Engine Harness. 6spd Transmission Swap, Getrag 420G. RHD LW Single Mass Flywheel. E39 M5 Clutch. E39 M5 Shifter. Factory Car Phone. Factory 6CD Changer. Factory Electric Sunshade. Not So Factory Factory Electric/Heated Rear Seats. E38 Heater Valves. E43 M5 calipers/brakes
Sold:
1996 Oldsmobile Aurora; 194k miles but with a bad paint job and dented fender resulting in a payout to buy the 740i
Have you tested the air intake temperature sensor or replaced it?
Not sure how that is on the M60, on the M70 we have one inside the MAF = # 1 http://bmwe32.masscom.net/sean750/MAF_v12/Bosch_MAF[1].gif and one of each side of the intakes near the firewall http://bmwe32.masscom.net/sean750/sp...enumIntake.jpg
same with coolant sensor, on the M70 we have some, reporting to the cluster gauge, reporting to EML and reporting to the DMEs.
In case you get a cheap used 404 DME you can test and swap. Always the best to have a spare unit on stock.
Shogun tricks and tips for the E32 series are HERE!
The intake air temp is good. I just replaced the coolant temp sensor too. The 500 only idle I'm thinking is the DME, even the IAC is new and it made no change. There is no vacuum leaks either and the idle is dead steady at 500.
Sorry, I only have plenty of spare DMEs and EML for the M70 pre-facelift -156 and facelift -352, but nothing for the M60 with the 404 number.
Maybe someone here with a 740 has a spare DME and can lend it to you for testing. Also check in the E34 classifieds section if there is one for sale, there are some which always part E34, maybe one has a 540. But make sure it is then a 404, as some built years have a 484 and that does not work on your 404 (EWS/DWA)
Shogun tricks and tips for the E32 series are HERE!
Hi Yukon,
A very good friend of mine asked me to look in on your thread. I really need to know what sensor's wire is showing the improper voltage, and on what color wire. Furthermore, just to rule out various possibilities, do you have any other electrical issues or codes? What are the specifics of your car's odd behaviour?
Just so you know, I generally hang out in the General Mechanical forum, so I might miss further posts here. I'd like to help though, so if you care to send me a PM with a link, I'll see if I can offer any thoughts.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Hi Yukon,
I have answered your PM, but for the sake of making this thread meaningful to anyone reading it later, I'm copying and pasting your PM, and my answer, here:
Originally Posted by yukon101
If the car came to my shop with these issues, I would
(1) smoke test the intake system. This engine is the leakiest thing BMW ever built, and all your symptoms point to this. Intake leaks affect behavior more when the engine is cold, in open loop, and can't adjust.
(2) Use a slack-tube manometer, and test crankcase vacuum. Should be 3-6 inches of WATER. Normal vacuum testers measure inches of mercury. You can make your own slack tube manometer.
page 8, post #183: https://www.bimmerforums.com/forum/s...lacement/page8
(3) Clean and rebolt all major grounds, especially the one for the computers, and the engine ground .
Forget the voltages, chase the symptoms you're dealing with.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
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