Intermittent overheating !!

[Highlander646]

Hi,

I have a Disco 2 TD5 t Reg at 165k miles. Recently it has started losing nearly all power, over heating to just below red line and then staying there about a minute then temp falls back down to normal and power returns. If I turn off ignition and on again it returns to normal as well.

It does happen to any sort of pattern or time or anything like that, completely random most of the time.

Any ideas what is up? possibly coolant temp sensor?

Ali

 

[sierrafery]

Coolant temp sensor or it's circuit ... on coolant overheating it would have not failed back so easy from red to normal cos the coolant has a much bigger thermic inertia

 

[Highlander646]

Also noticed a large amount of air in the top hose from engine to radiator. Would this also contribute to the problem?

Going to replace the sensor anyway to see I that alleviates the issue.

Will update if it seems to work.

 

[sierrafery]

I dont think so... that loosing/getting back power with abrupt movements of the gauge are not specific for coolant/engine overheating... maybe your cooling system wasnt properly bled from the beginning

 

[thebiglad]

Also noticed a large amount of air in the top hose from engine to radiator. Would this also contribute to the problem?

Going to replace the sensor anyway to see I that alleviates the issue.

Will update if it seems to work.

Yes it will, as the coolant temp sensor is at one end of the hose. If the sensor is in air instead of coolant, it will get much hotter and therefore send an overheat signal to the ECU.

Sounds like it wasn't bled properly last time.

Is there any bubbling in the header tank when she is ticking over?