1991 BMW 525i Q&A
1991 BMW 525i Question: check engine light
When the check engine light comes on a diagnostic code(s) will be stored in the engine control module, and this code(s) will need to be retrieved to know where to start diagnosing this problem. This will need to go to a shop if you are not familiar with diagnosing and repairing fuel injection/ignition issues. http://repairpal.com/chicago-auto-repair - Bret Bodas
it could be a variety of issues...the most likely one could be that it is time to have the spark plugs cahnged and the car is due for a stage I tune up. - Visitor
The thermostat may fail resulting in engine overheating and/or illumination of the Check Engine Light. Replacement of the thermostat along with a complete inspection of the cooling system...
what to do when engine light apears
Check engine light stays on but i see no change in the car, it runns fine.Is it true, It most likey is the spark...