My 1993 318i (M42) still has a problem after service.

My car had a problem which caused a significant loss in power, deeper exhaust tone, erratic idles eyc.

I took the car to a shop and they sprayed a detergent into my throttlebody (2 cans), cleaned the Idle Controll Valve (ICV), replaced my spark plugs and ran a compression test. This got me my power back, put the exhaust tone back and fixed the idle somewhat. My compression is:

cylinder 1: 170
Cylinder 2: 175
Cylinder 3: 175
Cylinder 4: 175

However, frequently now the car will just die when I put the clutch in or put the car in neutral. The tachometer shows the normal drop in rpms as the clutch goes in but then keeps dropping past 1k rpms all the way to 0. This is when the car dies.

I have also washed/re-oiled the intake filter. The O2 sensor was replaced about 2k miles ago along with new transmission oil and differential oil.

The check engine light never comes on.

Anybody know what the problem is? ...MAF, fuel pump, cracked hose, clogged catlytic converter, etc??...

Any help is greatly appreciated! My car is barely drivable.

Thanks in advance.

is the intake dry?

This sounds like a job for the stealership

I allowed the intake to dry after oiling it...which was a week or 2 ago.


As for the stealership....should I take it there? I allready took it to a local place that works on BMWs...but then again...they couldn't fix it the first time.

Thanks for the replies.


Anybody else have any ideas???

Check you ICV. Do a search for Idle Control Valve for a quick fix on this. It may be as simple as spraying some throttle body cleaner (teflon safe ONLY) downstream of your MAF with the car at idle to clean the ICV. I had a similar problem and this helped. THe ICV bypasses the throttle body and passes air to the intake directly. It's part of your combustion control and spefically controls - you guessed it - idle speed. If it's dirty, or sticky, your car will starve for air and voila! no more rpms. There's a nifty write up on how to clean the ICV in place. Again, do a search here.
Good luck!
MrMonte

Don't roll over and take your baby to the $tealer! Don't do it! My knucklehead mechanic couldn't solve this problem on my car either. But the folks here on BFC could, for the low, low price or nothing! My mech has since been fired, as I now have tech resources available, I'm mechanically able, and have a new passion for taking on whatever I can before paying someone else to do it for me. :buttrock

Check for loose/cracked vacuum hoses. The biggies would be your intake hoses. If there's a vacuum leak, the car will run fine with gas, but stall at idle.

Check for loose/cracked vacuum hoses. The biggies would be your intake hoses. If there's a vacuum leak, the car will run fine with gas, but stall at idle.


I agree. I remember heifetz17's Air mass meter boot, (which he still owes me money for), was all cracked to sh*t. The car wouldn't even idle or stay on with a little gas. His was BAD.

This sounds like a job for the stealership



don't ever give advice like that again.


we will never refer people to dealerships.

always encourage to DIY.

definately check for vaccum leaks. Are your lights dimming also?


Basically what i'm asking is whether the voltage or the rpms are going down, or both?

If you can get a leak down test, that would help.

Will a leak down test determine if the hoses have leaks? How much would it cost about to just buy all new hoses from the dealer? I replaced the hose that goes to the ICV from the intake a few months ago so I highly doubt its that one.

How do I know if my voltage is going down? The rpms drop to zero when the car dies....from what I recall there was no diming in the lights at all.

Thanks again.