Thermostat maybe?

[Billathome65]

Hi guys

About two weeks back I had to go and pick something up in the middle of rush hour the time I try to avoid driving.

Anyway I was caught in very slow moving traffic my pet slug was with me and ran ahead to see how far traffic was backed up

Anyway I hear beep beep beep looking at the dash I see the coolant gauge was of the scale so pulled over to check the issue thinking I may have sprung a leak?

When I released the reservoir cap expecting to have to dive for cover there was no hissing etc the reservoir was full but the water was only lukewarm so my thought is the thermostat?

Any other thoughts and where is the thermostat situated on the C3 is it easy enough to replace?

Cheers guys

[white exec]

Quite possible that the dash temperature gauge has a coolant temperature sensor all of its own, and this may be mis-reading. Some engines have up to three of these sensors, feeding different parts of the system.

Even though no coolant loss, was the engine over-hot?

[Paul-R]

I think that all modern engines are under control of an ECU and have only one temperature sensor. The ECU monitors the temperature and sends information as required to various devices - temp gauge, temp warning light/beeper, fan motor(s), engine timing/mixture, glowplugs (diesels), etc, etc.

Having said that to me it seems to me that if the water isn't actually hot then it must be the temp sensor at fault. No idea where it is on a 1.4 though.

[GiveMeABreak]

Yes, it would help if we had a VIN for the car so we can assist further.

[white exec]

XM diesels have three coolant temp sensors:
- one for the dash temp gauge
- one for the injection ECU
- one for controlling the engine cooling fans
All three are fitted into the coolant exit point, where coolant exits the cylinder head.
Not sure how much of this carried over to Xantia and later engines.

[Paul-R]

I did say modern!

[white exec]

The circuit diagrams have been checked, obviously...
Point taken, though, Paul.

[Paul-R]

Another possibility is that the cooling system has air in it and needs bleeding. Again, I've no idea where the bleed valves are (or even if it has any) but as this is a zero cost option it'd be the first thing I'd try.

[Billathome65]

Cheers for the information guys some stuff to look into then.

Bill