Overheating issue.

Good morning all. Got 2005 TD4 which is running fine. Just been on a long run with her and noticed temp gushiest all good until stopped at traffic lights. Temp the roses to around 1200. Then goes back down once on the move again. No issues re heater all good there. Seen lots of posts re lazy thermostat poss being culprit . Also saw there was a quick fix for this issue if it is indeed the thermostat. Your views and advice please. TIA.

The TD4 thermostat normally sticks open over cooling the engine, but I guess it could be sluggish to open instead.
What makes you think it was overheating? Did you measure the engine temperature with the live engine data? Or was it displacing coolant from the reservoir? Or was the high temperature warning light on the dash on?

No warning lights came on. I was back on the move before the temp gauge passed the 1200 point. It may not have gone further but I was wondering whether that was a normal thing to happen. The temp gauge dropped right back down again once I was moving. Any advice on tests I could do would be appreciated. Thanks.

what does 1200 refer to with respect to temperature?

Apols. The needle was in the middle then dropped back once I was moving. It could have moved past the middle which would indicate the engine getting hotter. This is something I will need to test I think. Just let it idle for a while. Just need some advice on the best way forward. Thanks.

where does the needle sit when you are driving normally?

Roughly between zero ( cold) and the middle as described. No issues with the heater that’s fine. So around 1000 o clock if you like.

I understand now, 1200 is 12 o'clock
someone else may come along and correct me, but i would expect 12 o-clock (vertical) to be the normal running display, if on your car its normally at 10'oclock then its running too cold - thermostat stuck open

Brilliant thank you. I gather it’s a bit of a mission to change the thermostat. Is there another fox for the problem. I saw something about putting a second thermostat in one of the inlet hoses ?

Gooders200 said:

The needle was in the middle then dropped back once I was moving. It could have moved past the middle which would indicate the engine getting hotter.

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Ah yes, that's not overheating then. Mid way on the gauge is the normal running temperature, which is between 75°C and 114°C.
If the gauge is below half way, then it shows the engine is above 35°C but below 74°C.

That’s great thank you. Thought it the thermostat may need changing. Really appreciate the help.

Best of luck to you with that job.
People usually put some renault thermostat somewhere instead.

Gooders200 said:

That’s great thank you. Thought it the thermostat may need changing. Really appreciate the help.

Click to expand...

It does, but be warned, its a 4 hour job, and that's for a retired mechanic.

Putting the Renault 5 thermostat in the top hose is a fast and effective modification.

the Renault 5 thermostat job can be seen in a vid,
via this post:
https://www.landyzone.co.uk/land-rover/td4-thermostat-replacement.353427/#post-4718322

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