Author Topic: Check engine light (Read 2933 times)

mgold · « **on:** March 10, 2008, 11:41:12 AM »

So, on Saturday I replaced my ICV and valve cover gaskets (they were leaking oil onto the first two spark plugs). I cleaned up the old plugs and plug boots before reassembling everything. It fired up, it smoked for a minute or two as it burned off the oil that had seeped into the cylinder head when I extracted the plugs, but then everything seemed just fine. Yesterday when I pulled into my sloped driveway, the car died. At first I suspected that I simply missed the shift and stalled it... but then it wouldn't start at all. I popped the hood and found that one of the battery terminals had corroded over, so I pulled the battery cable, and cleaned it all up. After doing that it sook a few seconds then fired up and I was able to pull in just fine. This morning, she fired right up, idled fine, but when I would idle at a traffic light for about 45 seconds or so, the check engine light would come on. If I bliped the throttle, even just a tiny bit, the light would go out for another 45 seconds or so. The car has a brand new O2 sensor, a reasonably new rebuilt alternator, the battery is about 3 or 4 years old, the plugs, NGK's are about a year and a half to two years old, and the plug wires are originals with 210k. Any thoughts as to what's going on? I was thinking about trying new plugs first to see if these ones got fouled.

Cobra Jet · « **Reply #1 on:** March 10, 2008, 07:45:18 PM »

Have you checked for any stored codes yet?

How old is the crank & cam sensor? I had an issue with my prior 95 M3 where it would be hard to start sometimes (regardless of outside temps), then while driving or coming to a stop, the car would idle slightly rough or sometimes it would stall. The CEL would flicker, but nothing more than that and would go away once the car was idling better or once driving again. Eventually one day on the way home from work, the car died instantly while driving - no warning at all, it just shut off as if turning off the key. I coasted to the side of the road and while waiting for a flat bed service to tow me home, I pulled the codes (using the E36 gas pedal trick) and once home I looked up the failure code online. The culprit was the the crank positioning sensor, it just crapped out. Cost me $90 for a replacement sensor and some time for me and a friend to install it, but it was fairly an easy fix and the car was up and running fine after that. The crank and cam sensors can fail due to age, accumulated miles and of course underhood heat. The sensors & associated wiring will look perfectly fine visibly, but internally the wire deteriorates which causes the failure.

Just a guess, but if it were me, I would try and pull codes first, because there may be some stored codes even if the CEL is not illuminated.

mgold · « **Reply #2 on:** March 11, 2008, 09:49:49 AM »

Thanks, I'll keep that in mind. Strange thing is that it seemed fine this morning. I'll still go ahead and replace the plugs, and I'll check to see if the CPU throws a code at me.

///m42 sport · « **Reply #3 on:** January 15, 2009, 11:29:11 PM »

updates?

bbarnumboy · « **Reply #4 on:** January 19, 2009, 10:54:00 PM »

can someone explain how you do the pedal trick to check codes? i throw a code everytime i am at idle for aboput 30 seconds or more, and i think it may be the O2 help please

bbarnumboy · « **Reply #5 on:** January 21, 2009, 06:01:50 PM »

ok ifgured it out nevermind. turn key to accessories pump gas pedal 5 times and it starts. thanks