Please help, Pre-owned purchasing decisions.
I am considering getting a 1992 400 SE. The check engine light (malfunction indicator light) is on.
What would be the cause of the check engine light on a 1992 400 SE?

The car has only 44,000 miles and had scheduled maintenance service up to 37,500 miles at MB dealer, according to the maintenance book. The car seems runs fine performance wise with no strange noises or overheating.
I called the local MB dealer and they told me the emission (bad O2 sensors) might be causing the CEL to comes on.
They also said, it might be as simple as tighten the gas cap? I am not sure if that is true or not.

I have checked the threads regarding the check engine light subject, but did not find the answer.
Any help would be greatly appreciated, thanks in advance.

 

The answer is to hook the car up to the appropriate diagnostics equipment and read out the fault codes. You can take the car to a Mercedes mechanic (or dealership) that has the diagnostic equipment and get a PPI (pre-purchase inspection) including a computer diagnostic readout.

Or you can try to read the code yourself with a handmade blinker:

http://www.v12uberalles.com/pulling_codes.htm

The check engine light is primarily for emissions related problems, so O2 sensors and a poorly sealing gas cap (or poorly fitted cap) are good guesses, but you just don't know until you read the exact fault codes.

Brett

 

Hello Brett,
Thank you for your kind advice for the check engine light on 1992 400 SE. When I did farther inspection & test drive, I found some problem (mis-fire) on engine. I decided to pass this car.

PS. The miles on this car is 64,000 miles not 44,000, I mis typed.
Thanks again for your help.
JT1.