Hello there and welcome to the BMW Car Club of America.

If you are a BMW CCA member, please log in and introduce yourself in our Member Introductions section.

Cold start misfire

Discussion in 'E39 (1997-2003)' started by markvw, Apr 17, 2011.

    markvw guest

    Post Count: 2
    Likes Received:0
    When I started my '99 528i one morning, the engine started misfiring and the check engine light came on. I stopped at a local coffee shop and when I restarted the vehicle, the engine ran fine. The codes said there was a misfire in #5 and #6. I changed the plugs and cleared the codes. Ran fine for two days and then the misfires started again. Went to my local BIMRS shop. They read the codes but couldn't reproduce the problem. Paid about $350 for a fuel injection and fuel induction service. Car ran fine for two days but the problem reappeared today. After stopping for lunch, the car ran fine and the check engine light went out. Any suggestions? Thanks very much.

    ViolinARC guest

    Post Count: 178
    Likes Received:1
    Misfires are tough to diagnose but...

    Could be a few different things but mine turned out to be the CCV. There were other symptoms, which became very apparent i.e. rough idle when cold, misfires, lean bank, blue smoke on start. From your description, it could also be a vacuum leak, cats, MAF, coils, etc. so it would be good to ask for the actual codes from your repair center to narrow down the possibilities...

    I DIY replaced the CCV for $50 and it all went away...;)

    EDIT: I forgot to mention that I had been experiencing misfires for a while before the big stuff started happening (poor performance, rough idle, blue smoke and a "warbling" sound). When I opened up the old CCV, there was a minor tear on one side of the diaphram and a major tear on the other side. I believe that once the major tear occurred, is when the major symptoms appeared. ;)

Share This Page