Is this a faulty thermostat?

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clk320x

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Tesla Model S, Model X & Mercedes W212 /// Previous: Jaguar XFR, Mercedes E320 CDI, C32 AMG, CLK 320
Today on a 60 mile run my E250 CDI (651) seemed to fluctuate between 73 - 80 degrees and took around 25 miles of motorway driving to warm up to 80 degrees. It usually sits at around 87 degrees and reaches this temp after around 7 miles of driving.

Is this the classic early thermostat failure? The water pump was already replaced about a year ago now.

Anyone know the labour time for the stat? It seems to be around £60 from MB for the part. Any clues who the OE manufacturer is?

Thanks!
 
It is the early sign of failure, mine was acting the same. I think I was charged an hour of work or even less.
 
Thanks all. Will I need to purchase new coolant? or is not much lost when changing the stat?
 
Probably a good idea to change the coolant anyway.
 
Syphon out the expansion tank and park facing up a slope and you won't lose any coolant .
 
No need to replace coolant other than that you loose during the replacement process (minimal usually)

I wound be asking Steve at MB Edinburgh for a quote. Items like this are crucial for the correct running of the engine so it is good to have the OE part.
 
On my E350 I only lost a bit of coolant, no big deal, but will depend on how the thermostat is situated in the car. I just topped up and was good to go, 1/2 hour job on that engine.
 
Hi guys,

Still no further,

Now the car seems to get up to temperature in the normal time, runs at the correct temp when travelling around town/low speeds, when on the motorway though the temperature drops to around 60c?

does this still sound like a stat?

thanks!
 
Hi guys,

Still no further,

Now the car seems to get up to temperature in the normal time, runs at the correct temp when travelling around town/low speeds, when on the motorway though the temperature drops to around 60c?

does this still sound like a stat?

thanks!

Yes the faster you go the more cold air is forced onto the radiator, hence the cooling .
 
Great guys, thanks a lot! :)
 

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