Engine Light On

Tiny
FRANXUA1
  • MEMBER
  • 1998 BMW 740
  • V8
  • 2WD
  • AUTOMATIC
  • 100,000 MILES
I have a 1998 BMW 740i with the code P0300, P0308, P0306, P0100, P1585, the car runs great, but I have noticed that it kind of smells like antifreeze when its running, I want to fix these problems, can anyone tell me what these codes mean and how I can fix them!
Thank you!
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Sunday, May 1st, 2011 AT 2:17 AM

6 Replies

Tiny
KHLOW2008
  • EXPERT
P0100 = Mass or Volume Air Flow Circuit.

P0300 = rando = misfire
P0306 and P0308 = specific cylinder misfire, cylinder 6 and 8 are misfiring.

P1585 = Misfire detected with low fuel.

You have a fault with the MAF and it could be the cause of the misfiring or the misfiring could be a fault with the sparks plugs or related components of the respective cylinders.

If you have overheating and coolant losse issues, it could be a bad head gasket resulting in the misfiring.

Have a compression test performed to ensure the cylinders compressure are up to specs.

The MAF is the prirority, it should be resolved first.
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Sunday, May 1st, 2011 AT 2:10 PM
Tiny
FRANXUA1
  • MEMBER
Thanks.
Any idea on how to fix this, I want to do it myself.I have some knowledge about mechanics, so I want to try fixing it myself.
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Sunday, May 1st, 2011 AT 4:08 PM
Tiny
FRANXUA1
  • MEMBER
By the way the car does not overheat, but there is a small coolant leak.I dont know what the part its called, it looks like two small cylinders, or sensors, that are behind the engine, thats where the leak is at.
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Sunday, May 1st, 2011 AT 4:12 PM
Tiny
FRANXUA1
  • MEMBER
I found the name of the part that leaks, BMW E38 7-Series Heater Control Valve W/ Auxiliary Water Pump OEM
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Sunday, May 1st, 2011 AT 4:24 PM
Tiny
KHLOW2008
  • EXPERT
I am no expert with this vehicle but I will try my best and hope it is good enough.

The first 3 charts are for the MAF. Print and join them together and go through them and see if you can come up with anything.

As to cylinder 6 and 8 misfiring, have the comppression tested. Check the spark plugs and related components.

We start here.

Good luck.
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Sunday, May 1st, 2011 AT 4:29 PM
Tiny
KHLOW2008
  • EXPERT
The part is for the heater system and if it is leaking, check if it is the hosesor unit itself. If unit, it would have to be replaced.
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Sunday, May 1st, 2011 AT 4:31 PM

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