5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
My 1999 BMW 528i intermittently dropped its top speed to 20-30mph. Had the codes read by Advance which gave P0303 Cylinder 3 Misfire Detected, and P1580 Throttle Valve Mechanically Stuck. Took the car to an independent BMW garage. The garage replaced throttle body. A week later the car began to sometimes misfiring when started then ran rough, or started without misfiring and ran smoothly. Again had the codes read by Advance which gave only P0303 Cylinder 3 Misfire Detected. Today on the way back to the garage, the engine temperature began to climb into the red, so immediately parked the car and had it towed to the garage. The garage said cylinder 3 had low compression (20#s) which may indicate blown head gasket, cracked piston or cracked engine head. I asked them to pull the head and tell me what they find. Any suggestions?
The garage said cylinder 3 had low compression (20#s) which may indicate blown head gasket, cracked piston or cracked engine head. I asked them to pull the head and tell me what they find. Any suggestions?
Pulled the head and found previous owner had helicoils installed in headbolt holes, versus timeserts which can be torqued tighter. Previously they probably just torqued as much as they could which was not enough to prevent leaking. Head passed a pressure test, so used timeserts and replaced head gasket and head bolts, along with repair or one bank of intake cam bearing stud holes which pulled out.
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