Engine Light On

1998 BMW 740
100,000 MILES • V8 • 2WD • AUTOMATIC
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FRANXUA1
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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!
May 1, 2011 at 2:17 AM
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KHLOW2008
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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.
May 1, 2011 at 2:10 PM
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FRANXUA1
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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...
May 1, 2011 at 4:08 PM
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FRANXUA1
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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...
May 1, 2011 at 4:12 PM
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FRANXUA1
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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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May 1, 2011 at 4:24 PM
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KHLOW2008
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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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May 1, 2011 at 4:29 PM
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KHLOW2008
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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.
May 1, 2011 at 4:31 PM