Temp Guage Problems

[zendog]

Have a 52 plate C5 2.0 HDi and have an intermittent problem when the temp guage which will suddenly rise to the highest point and the STOP light will come on on the dash. The first time it happened I called the AA out, by the time they arrived it had stopped doing it but they checked everything thoroughly (coolant levels / pressure etc.) and could find nothing wrong. I drove home (about 100 miles) with no recurrence. It keeps happening now and again with no logical reason sometimes an hour into a long journey sometimes on a 10 minute drive to work. The car does not appear to be overheating the coolant level is fine with no apparent leaks.

 

Any ideas? Should I start by changing the temp sensor?

[techbod]

2 things to consider.

 

1/. coolant temp sensor faulty which will effect the cooling fans,

2/. the thermostat could be sticking,

 

change them both as they are not expensive and when did you ( ever change the coolant? ) now might be a good time :lol:

[fatgut]

Have a 52 plate C5 2.0 HDi and have an intermittent problem when the temp guage which will suddenly rise to the highest point and the STOP light will come on on the dash. The first time it happened I called the AA out, by the time they arrived it had stopped doing it but they checked everything thoroughly (coolant levels / pressure etc.) and could find nothing wrong. I drove home (about 100 miles) with no recurrence. It keeps happening now and again with no logical reason sometimes an hour into a long journey sometimes on a 10 minute drive to work. The car does not appear to be overheating the coolant level is fine with no apparent leaks.

 

Any ideas? Should I start by changing the temp sensor?

When ours did this (same engine) it turned out to need a new thermostsat. It was intermittent, and when it happened it was usually a few minutes after a cold start.

[PICASSOCONVERT]

I've just had the same problem (2.2HDi). After about a mile to a mile and a half from a cold start the temperature gauge would start to move normally and then go momentarily to the top of the gauge. At the same time the "Stop" light would come on. Then the water temperature gauge and the oil temperature gauges would both go back to rest at the bottom.

 

Stopping the car and restarting the engine would result in the water and temperature gauges reading normally, although on occasion (when it took me a while to find a stopping place) the gauges started to operate normally again. Playing around with the old thermostat in hot water showed it was a bit "sticky" in operation.

 

Replacing the thermostat seems to have cured the fault, but with an outside temeperature of 2C today it took some time to get the engine up to a temperature where the thermostat would open.

 

Just one point on fitting the thermostat - is it really the case that the EGR pipe has to be disconnected to give enough headroom to remove the thermostat cover? I could get the bolt nearest the EGR pipe out with a bit a jiggling but I couldn't get the cover out without unbolting the EGR pipe from the inlet manifold.

 

David