Overheating problem- any suggestions?

[slk 32]

I would like to ask for any advice- for the last week or so my SLK has been running hot. It just had a B service at Mercedes in December and I do approx 4000 miles per year ( weekends only). The normal operating temperature has gone up from 85 degrees to just below the 100 mark which cannot be good- especially with the summer coming up. i have for the last couple of days been running with the heater on - just trying to suck some heat from the engine compartment ( curiously this does not seem to blow as hot as it did before). I will need to get this fixed and am resigned to the fact that as a car gets older stuff just wears out- any idea what the issue could be - thermostat possibly?

Aany advice gratefully received

Edited by slk 32 on Monday 12th April 09:23

[SLacKer]

As a reference mine runs with the gauge in the horizontal position when hot.

Does your fan come on when hot? Have you lost coolant? Have you had any recent work done on the cooling system?

[slk 32]

thanks SLacKer for you response

no work since i've had the car (2 years)

the horizontal is where mine used to run at (85 degree mark) but now is just below the next mark- as you are aware there engines produce a terrific amount of heat soak
fan does come on (no more than usual)

smells hot under the bonnet too

Edited by slk 32 on Monday 12th April 11:55

[Orb the Impaler]

Normally your heater not blowing hot might indicate that you are very low on coolant (don't ask me how I know this!), however I'd be inclined to think a partially blocked radiator core (or potentially a water pump, but I'd consider the rad first).

You can have them flushed or if you need a replacement I can thouroughly recommend having someone re-core the rad.

Look up your nearest Serck-Marston rad place - tres cheep

[SLacKer]

It could be a thermostat staying shut longer or indeed what orb said. Have you checked your coolant level (I know there is a light), when was the last time you had the coolant changed over?

Have you checked the main belt for wear or being slack it does the water pump, ac compressor etc.

Edited by SLacKer on Tuesday 13th April 08:27

[slk 32]

Thanks for the advice guys- i will check the coolant level this weekend- would have thought this would have been done during the service though (perhaps wrongly)