After almost a year sitting due to a love hate relationship I took the booster...

After almost a year sitting, due to a love/hate relationship, I took the booster pack out behind the shop, popped the hood on my '92 750iL, fired it up, and drove it home. During my 15 mi voyage home, I reflected on our relationship......when it runs good, I love it.....when it acts up, I want to burn it with fire. I've questioned selling it time and time again, but just can't bring myself to do it, and after driving it home tonite, I decided it's time.......time to bring it in the shop, figure out the problems, fix them, and start driving it again......with that being said, I have a few questions......

1. The main reason I quit driving it, is because it developed a nasty battery drain, and became unreliable......at one time, someone had given me some information about a battery drain issue with the heat/a.c system that was apparently very common on these cars. It will drain the battery dead over nite one nite, the next it might be fine. At times, I can hear a hum coming from behind the center dash even after the key has been off. I have since lost the info about the battery drain issue.....has anyone seen this, or maybe know what it might be, before I start tearing into everything?

2. Does anyone know of a non hydraulic conversion for the rear struts, or anyone who can rebuild these reasonably, and not $800 each for new ones?

3. Park/neutral or position switch: anyone know where I can find one? I replaced the transmission in this a little over a year ago with a god known used unit....it shifts fine, when it wants to, but often it will go into safe mode, and I will have to cycle the key to reset it....if I move the shifter one way or another a bit it will come out of it, so I expect that the position switch on the side of the trans is bad.....

4. Electronic throttle bodies: I have tore both down, cleaned, and regreased, but when it's cold, the EML light will come on and it will drop 1/2 the cylinders....it would throw a throttle body code when it did this....I just can't remember for which side......maybe a bit more cleaning is involved at the electrical terminals?

5. Valve adjustment: I've had a ticking for some time in the top end, which I expect is loose valve lash......at some point I need to pull the intake to replace valve cover gaskets, and figured that would be a good time to adjust them....I just don't know if they have shims or what to adjust the lash....

Thanks for any info anyone can provide!

%d comments
  • Not sure about #1...

    #2... You can buy the conversion from Baverian Motorsports. I got mine for about 500 all together. That included the struts.

    #3 Baverian Motorsports

    #4 mine is doing something like this now. I think it's a fuel problem. Seems exaggerated when cold outside.

    #5 There is an adjustment thing on the passenger side of the motor where you can tighten the chain.

    www.bavauto.com

    www.e38.org the click on e32

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  • 4. Also if your battery voltage is erratic (such as when cranking on an almost flat battery) it will go into limp home mode

  • Thanks for the links, Kelly...........that's exactly what I was looking for. Between that, and a couple forums I was picking thru tonite, I have 2 distinct possibilities as to what the battery drain is....either the electronic climate control system, or the door lock heater in the drivers door staying on due to a bad latch. I had been having problems with the drivers latch for a while, would really have to slam it to latch it. I do have another '88 750IL parts car that has a good latch in it. I suppose that would be the most likely place to start. I have a different passenger front door for it, and there was SO much brittle, thin wiring in the doors.......

  • Glad I could help!!

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  • Skawn, After hearing all of these issues, I am no longer impressed with the BMW V-12 engineering genius's! I have experienced all of the things that you have noted....BMW is leaving out too many things that are cheap, such as 'safety wiring' that all aircraft include. This looks like 'designed in $ervice Greed' and not excellent German engineering. Also, I had the battery-drain problem on my Cadillac. It was the pneumatic pump going on while parked; I ended up ripping the wires out of the pump and now everything is fine ! I never went through this with my 1970 BMW 2002...