i have had my renault clio (the new edition out in late 1998) for several months, and recently i have noticed the thermostat gauge does not move.

it used to rise gradually when i drove, but no more than a few notches. i only travel small journeys around town really, so after noticing that the level wasn't moving, i assumed it was as the engine was still 'cold' and hadn't had time to warm up.

however, after going on several longer journeys, there is still no movement in the level of the thermostat (it remains still horizontal at the bottom)- which is a worry seeing as if the engine overheats i will not know of it. it has been like this for several weeks now, and with an MOT arriving (even though i was told this wouldn't fail it??), and some long distance journeys planned for summer- i'd like to get it sorted incase it causes any other problems.

any suggestions on what i should do?
and is it better to see a renault dealer?

thanks for answers in advance.

kerry.

kerry beeston, July 2007

thanks for that, youve saved me the hassle of ringing a mechanic who could rip me off!

cheers.

kerry.

kerry beeston, July 2007

How to check for a stuck thermostat
With the engine cold, remove the radiator cap and start the engine up. Normally, at startup, the coolant should be still. But as the engine warms up to normal operating temperature, the thermostat should open and the coolant will start to be pumped around the engine. Based on this normal thermostat operating scenario, you should be able to determine if your thermostat is stuck open (coolant flows) or closed (coolant does not flow).

Finally, This should be done only as a LAST resort and should confirm any doubt.
Remove the thermostat from its housing (Follow the top radiator hose from the radiator to the engine - this is where the thermostat should be), remove the hose from the housing and then unbolt the housing, remove the thermostat. Now place the thermostat in a clear jug of boiling water. You should see the thermostat open if it is working - If it does open, your problem lies elsewhere, If the thermostat fails to open, it is faulty.

Cheers
Dr Nom

Dr Nom, July 2007