300 Tdi - Faulty Engine Temperature Sensor?

I have a 300Tdi and when I switch the engine on the dashboard engine temp gauge goes straight to the red area. However as you start moving, and assuming the engine is getting air circulated, the temp reading drops immediately below half way.
I’ve checked the coolant levels which are OK and the engine fan is not kicking in. Does it sound like a faulty sensor?

The sensor works by a variable resistor activated by the engine heat. If it goes directly to hot when you switch the engine ignition on and the engine is cold, I would suspect the sender gauge wire has a short to earth somewhere, or the sender is faulty. Try taking the wire off the sender and turning on the ignition, if the gauge stays cold, the sender is at fault. If the gauge shoots up, there is a short in the wire.

Or the gauge itself could be the problem, but the only way to test it may be substitution of a known good gauge.

The only way to get a proper temperature reading on a Land Rover is to throw the Land Rover gauge away and fit a good aftermarket gauge.
Even when it looks as if the gauge is working correctly, with the needle in the middle of the gauge the actual engine temperature could be 88 Deg C OR it could be 95Deg C. Take your pick.
On a 300 Tdi once the needle is in the red. The engine has overheated.

mike

gemini said:

The only way to get a proper temperature reading on a Land Rover is to throw the Land Rover gauge away and fit a good aftermarket gauge.
Even when it looks as if the gauge is working correctly, with the needle in the middle of the gauge the actual engine temperature could be 88 Deg C OR it could be 95Deg C. Take your pick.
On a 300 Tdi once the needle is in the red. The engine has overheated.

mike

Click to expand...

Yep I can vouch for that , the head gasket went in my 300tdi, temp gauge read normal till engine cut out, then it near bent the needle at the top of red, so expensive repair bill...