When you pull misfire codes on all cylinders of a BMW. it may seems like a simple fix. But when all the usual suspects check out ok, your dream job can turn into a real nightmare.
Even with the assistance, this was still a challenging job. eventually identifying the fix as replacing the serpentine belt. And while it took some time to figure out, our perseverance and the feeling of peer to peer support helped this tech stay focused in the face of frustration until we got the job done.
Concer: Multiple BMW trouble codes - 202, 203, 238, 240, 239, 228 and 227
Tests: - Inspect General tune ups parts: condition of the spark plugs, filters and so on. Freeze frame data for fault set can gives some insight along with fuel trim numbers. Vacuum leaks at idle will show up on idle trim as adding fuel to maintain mixture.
- Check for vacuum leaks
- Test the crankcase breather valve. The crankcase should have negative pressure of 10 to15 millibar. This equal about 025 to 0.50 PSI at idle.
- Check fuel pressure, 0.7 is the operating pressure in all operating modules.
- Air sensor grams per second value of 5 at idle would be a good number.
Potential Cause: - Maa Air Flow (MAF) sensor
- PCV Valve
- Leaking engine vacuum
- Fuel Pressure
Confirmed Fix: Replace Positive Crankcase Ventilation (PCV) valve.
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12-15-2010, 07:20 PM
Fast Fix for 2001 BMW 330i Base 3.0LT
