Clk320 still too hot!

[Mickey42]

Hi all, 2004 clk320. I’ve had a couple of these before and roughly know how hot they should get. But this one as a convertible I’m keeping, but the temperature is getting to 100. I’ve changed the thermostat and water pump but it’s made no difference. Any ideas to help me out please.

Thanks.

 

[bembo449]

possible blocked radiator ??

 

[Mickey42]

Thanks bembo, do you know how I would find out if this was the cause? Thanks mate

 

[Blobcat]

Thanks bembo, do you know how I would find out if this was the cause? Thanks mate

By checking the radiator for external blockages… bent fins and flushing it out to check it’s not gummed up inside with rust or gel from incorrectly mixing engine coolants

 

[bembo449]

run the car upto temp then get your hand and feel all over the rad OR get a temp gun

 

[mioba]

WHS above, simply by hand.
When was your coolant last changed? Every 15 years its due following a good flush and clean of the system

 

[ajlsl600]

Hi all, 2004 clk320. I’ve had a couple of these before and roughly know how hot they should get. But this one as a convertible I’m keeping, but the temperature is getting to 100. I’ve changed the thermostat and water pump but it’s made no difference. Any ideas to help me out please.

Thanks.

Have you checked the sender? With temp gun. Is it ACTUALLY overheating or just indicating as such.

 

[Mickey42]

Rad is hot top and bottom and expansion tank hot too. When should the fan cut in as it won’t cut in until around 95 and even then you only get about 15 seconds worth.

Thanks again everyone

 

[alexanderfoti]

Probably faulty fan control module then. It is PWM Controlled and should spin slowly at 92, then progressively faster. The actual actuation temp can be checked (And changed +-10degC) On star

 

[Mickey42]

Thanks for all your advice. I currently only use her for work which is a 3 mile drive across town. I drove her back the long way yesterday via the A14 thinking that a 65mph drive would push more air through the rad and keep her cool, but the complete opposite happened, even with the heaters on full to assist she still went up to 100 and smells hot. This weekend I’m going to give her a rad flush, if that doesn’t work then I feel she needs a new one. Surely there is nothing else that could be wrong regarding the water system?

Thanks again.

 

[ajlsl600]

A nu of possibilities w pump loss of efficiency(not too likely) failure of cooling system to seal , lower boiling point, inefficient cooling fan, faulty sender faulty control of fan, obstruction of cooling system, see if any codes appear relative to electrical or electronics rad easy to test take out fill it see water comes out at same rate or near to going in. But my money is on the electrics of fan control.

 

[Mickey42]

Have just put rad flush in so awaiting results. Have just had it ticking over plus some sitting at 2000rpm for 30 mins. Temp gauge sitting at 100 and the fan only kicks in then for 20 seconds and then off for about 3 mins, no alteration of temp gauge whilst fan is on.

Thanks

 

[Mickey42]

Rad flush = no difference

 

[Flyinspanner]

If your car is at 100, and the fan only goes on for 20 seconds, then I would guess that is the problem - either the temp sensor is dying or the fan controller is?

When hot, engine ticking over, do the rad hoses feel/look ‘inflated’? - maybe get a sniffer test to rule out the start of a failing head gasket?

 

[Mickey42]

Hi Fly, would that be the sensor in the block or the one in the rad? Cheers