SteffenSchu
Overheating and check engine light on Mercedes ML Class 2015: experience and tips wanted
Check engine light on
Overheating
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8 comment(s)
Hey guys, I also have a '15 ML class and had a similar problem. After 70k km I had a problem with the thermostat, but luckily it was fixed quickly. For me it was actually just the thermostat and not a wiring harness issue. Can you remember what you paid to get it fixed and if any other problems have occurred since? I would like to know what I might have to expect. Thank you very much!
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Well, in my case it was around €110 for the damage to the wiring harness after the visit to the mechanic. Since then, everything has been running smoothly again. This annoying malfunction of the coolant thermostat was also rectified and everything has been fine since then. So, hold your head high, fixing your problem might not be so dramatic.
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Thanks for the comments, everyone! I feel a bit better now. Based on your experiences, I'm assuming that it could be either the coolant thermostat or even the whole wiring harness. Annoying, but I realize that I can't avoid it and have to go to the workshop. I just hope that the repair won't be as expensive as yours, but what you won't do for your car. Learned something again and your answers were really helpful. Thanks again, guys! Until then, stay healthy.
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@Sibra
When the wiring harness in mercedes c 200 w205 2014 is smeared with oil , what should i do in this case , is it enough to clean the plug and the wires to ECU ? What detergent should i use ? Thanks in advance
Yes, you can clean the oil off the wiring harness. Use a non-conductive cleaner like electrical contact cleaner, which is designed for this purpose. After cleaning, make sure it's completely dry before reconnecting. However, it's crucial to find out why oil got there in the first place. It could be a sign of a more serious issue like a leaking gasket. If you're unsure, it's best to have a mechanic inspect it to avoid potential damage to the ECU or other components. Let us know how it goes and if you have any other questions.
@Prince93
I have replaced the small coolant tank directly under the engine cover, I got it from the parts accessories, so it is not original, could it be that the thermostat is not working properly because of this?
While it's possible that a non-original coolant tank could cause issues, it's unlikely to directly affect the thermostat's operation. However, if the tank isn't sealing properly or if it's not maintaining the correct pressure, it could potentially cause overheating issues. I'd recommend checking for leaks and ensuring the tank is properly sealed. If the problem persists, it might be worth having the thermostat checked by a professional. Please keep us updated on your progress and don't hesitate to ask if you have more questions.
Best Answer
Hey, I drive a Mercedes GL Class model year '12 and I had the same problem with overheating and the check engine light. In my case it was damage to the wiring harness. This is probably not uncommon with these models. It was a serious problem because the wiring harness connects pretty much everything in your car. It needed a thorough inspection and repair. My advice would be to have it checked by a mechanic. It could be that your coolant thermostat is OK, but is providing incorrect information due to the faulty wiring. So you'd better have it checked. As annoying as it is, it's better to have it out of the way. Acting as if nothing is wrong could cause even more problems.
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