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DISCUSSION => Engine + Driveline => Topic started by: Pitch-Black on May 20, 2009, 04:31:52 PM

Title: Another idle problem...
Post by: Pitch-Black on May 20, 2009, 04:31:52 PM

Hey guys!

I got a little idle problem.

When the engine is cold the base idle is fine!

But when its hot it idles around 1K and won't come down...

I have cleaned my ICV and checked for leaks.

Could this be my TPC(Throttle position sensor)?

If so,why does it only idles high when HOT?

Hopefully somebody can help me out!:D

Title: Another idle problem...
Post by: Pitch-Black on May 24, 2009, 04:34:52 PM

Update:

Also cleaned and checked TPS(workes fine)and...problem is still there:mad:

Could this be a faulty temp sensor(maybe in the AFM)?

Help please!:o

Title: Another idle problem...
Post by: DesktopDave on May 24, 2009, 05:57:43 PM

Might be that the coolant sensor is defective.  Usually a bad ICV will cause a wandering idle, not a high idle.  When the engine warms up, it'll need less idle speed compensation.  If not the ICV or the ever popular vacuum leak, might be that the coolant sensor isn't telling the car to compensate idle lower.  It's not the one on the radiator IIRC, that's for the fans.  It's on the engine somewhere, I'd figure under the intake on side of the head.

I'd figure you'd see a CEL though - did you do the stomp test?

Title: Another idle problem...
Post by: carl6405 on May 24, 2009, 07:34:40 PM

I had the same problem, heres what I did and found. Cleaned ICV and put a few drops of light oil down in there. Replaced my coolant temp sensor ($18 - Autozone) Also, there is a small, short vacuum line, that's kind of hard to see. My vacuum line was dry rotted. It's only about 4" long, small diameter,  connects from part number 7, vacuum box.
http://www.realoem.com/bmw/showparts.do?model=CA53&mospid=47490&btnr=11_1159&hg=11&fg=40
Last, but not least, the 02 sensor. Replacing the 02 finally fixed it. The other things helped, however. My idle was so bad, that sometimes the car would cut off, when i came to a stop.

Title: Another idle problem...
Post by: Blip Bavarian on May 27, 2009, 04:37:16 PM

Quote from: carl6405;72384

Last, but not least, the 02 sensor. Replacing the 02 finally fixed it. The other things helped, however. My idle was so bad, that sometimes the car would cut off, when i came to a stop.

i have the exact same problem, my car will not idle when hot.  It is completely fine when i start it up, but once it is hot it stalls upon idle.  I pulled the o2 sensor and it ran even worse.  Could the o2 sensor still be the problem??

Title: Another idle problem...
Post by: B318M42W on May 27, 2009, 09:28:00 PM

checked out the "did we ever find out the hot start issue" thread?

Title: Another idle problem...
Post by: Pitch-Black on May 31, 2009, 01:46:28 PM

Found the problem!:D

When i bought the car it was runnin on LPG(Liquid propane gas).

So they have been messing around with the idle adjust on the trottle inlet.

Fixed that and car runs like a charme!:)