My "Eheck Engine" light came on steady amber for a while, then went away after 3 starts. The manual says that it could have detected a fuel malfunction or an emission error, but can automatically clear itself if the error condition no longer exists. However, 2 days after it went away, it came back again (today). The only thing I can think of is that I exported the car from the US to Lebanon and the gasoline in Lebanon is not as clean as the US.
What should I do? Just wait and see if it goes away again? Any advise here is appreciated.
Vehicle: E320, SLK320, MKV Jetta TDI, Mini Cooper S
Location: Arizona
Posts: 1,678
RE: Check Engine Light
Always, Have the codes read to see what is turning on the CEL in the first place. It could be a number of things from a bad O2 sensor to a fuel problem or a misfire in just one cylinder. The code number will tell you and then you can better know how to fix it.
__________________
I assume no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user. Although careful precaution has been taken in the preparation of this information, I assume no responsibility for omissions or errors.
The CEL disappeared again after about 3 starts. I guess I have to get the code(s) read when I get the light again. What causes the mass air flow sensor to go bad? The car is a 2000 E320 with only 40K miles.
I would try to clean MAF sensor first. Obviously your problems is intermittent or border line case. But it will go bad eventually. Try using narrow tipped vacuum cleaner to suction-clean the sensor using extra care not to damage the sensor.
I have heard some people using electrical contact cleaner as well. But I have not.
Good luck. Let us know what happens. MAF sensor can cost anywhere from $325 to $385 with discounts.
I changed the air filter this morning and vaccum-cleaned all the dust from the air filter compartment and the hose where the mass air filter sensor is located. If the problem returns, I will remove the mass air filter sensor and clean it as suggested in this forum.
One question: Do I have to disconnect the battery before I can remove the mass air filter sensor?
The CEL came back and I removed the MAF sensor and cleaned it with carb cleaner and electrical contact cleaner. A day after I put it back, the CEL came back again. Finally I took it to a Mercedes shop (not a dealer) yesterday and got the codes read. Here they are:
The technician recommended changing the MAF sensor and claimed that the other faults (P0136 and P0141) are related to the MAF sensor. I found a Mercedes parts supply store selling a Bosch MAF sensor (an exact duplicate of the one in the car) for $150. So I bought the part and replaced it. It's been a day and no CEL. I am crossing my fingers. If it shows up again, I will update this thread.
Another thing I got done was a change of the thermostat from the original 87 degrees to a 71-degree one. The technician claimed that in warmer climates, it is better to not run the engine too hot. What do you folks think about that?
It seems like my CEL problem has been resolved by replacing the MAF sensor. I have not seen the CEL in about a week, whereas it used to show up every other day or so prior to the MAF sensor change.
The temperature gauge hardly goes over 80 degress after the thermostat change.
Linear Mode
