Temperature gauage C Class

[gregb]

Hi there, I am looking for a little help from your good selves, not really a problem as such, more of a niggle, but I would like to know if anyone has experienced the same thing.

I own a 2010 C Class 250cdi sport and just recently I have noticed the temperature gauge appears to give an erratic reading. The gauge when fully warm always used to sit at around the 90 mark. The gauge now as the car warms up seems to stop at around 80 and drops back to around 70. It may fluctuate like this for quite a while, even when travelling on a motorway journey where you would expect the car to be fully warm and run at a constant temperature, i.e 90.

I have noticed also, if you should wind the car up and make the engine work the gauge will go to 90 and stay there, it no longer fluctuates, this also occurs if you should stop the car and engine for a couple of minutes and restart it, the gauge will go to 90 and stay there.

Has anyone experienced this in their cars? I am thinking perhaps the gauge is faulty and sticking or the thermostat is faulty. The fuel economy hasnt suffered at all, and some days the gauge works perfectly normally.

The car is due its first service in June, do you think it would be worth mentioning this to the service dept and have it checked out? or is this normal and perhaps something I havent noticed before?

Thanks in advance for any help.

Greg

 

[st13phil]

It does sound like a possible thermostat problem, so I'd definitely report it when you book the service.

 

[gregb]

Thats was a quick reply, thanks. I think I will get it checked out at service and see what Mercedes say.

Cheers

Greg

 

[Uncle Fester]

Hi, sounds like a thermostat issue, would this be covered by the warranty?

 

[gregb]

I am hoping it will be covered by the warranty, I cant see any reason why it shouldnt be. My local dealer were very good dealing with a warranty issue involving failure of the Bluetooth, they replaced the head unit straight away, I hope they deal with this issue in the same way.

Thanks

Greg

 

[gregb]

For anyone who may be interested. I had the car serviced a few weeks ago and mentioned the erratic behaviour of the temperature gauge to the service manager.

After servicing my car and checking the cooling system and the diagnostics they could not find any faults with the car and gave it a clean bill of health, and to be fair the car performs normally anyway. At least I thought Mercedes now have a record of me reporting this to them if anything were to go properly wrong in the future, so I went away happy.

I took the car on a long run to the inlaws (500 mile round trip) a few days after having it serviced and since the trip the temperature gauge now works normally with no erratic behaviour.

I am not sure what the problem was (nor were Mercedes) but it appears a good long run on the motorway has fixed it!

Cheers

Greg