Erratic Coolant Temperature Guage

[Guest H_thegasman]

Got a 2001 model 115 tdi recently.

 

On the journey back from hols today noticed erratic readings from the coolant temperature gauge - initially I thought it was related to travelling up ordown hills - fell on descent rising on ascent - but later on not so sure.

 

The gauge was reading anything from 60 to 90 - even though the engine was warmed up and it was 20 outside!!

 

Surprisingly only happened on the A roads - ie cruiseing at 50ish in steady traffic. When i got onto the motorway seemed to settle down.

 

The cars got oil temp as well and that stayed plumb normal at 90 noother gauge problems I can identify.

[Guest nimrod]

Sounds like either a dodgy sensor or wiring to it! OR another case of the dash display unitgoing U/S :D do a search on the topic, there are a couple of members that are waiting or have had thier dash display units replaced because of a known fault on them!

[Guest H_thegasman]

I guessed that it is wiring, sensor or dash display - but how do i workout which. Is the Haynes manual any good for the 115 tdi - I thought it only covered the non high pressure injection?

 

And where is the sensor? I ve had a quick look this evening and the only senor I can find is one on the off side of the radiator, about 8 cm from the top with three wires going to it. If this is the sensor, Perhaps this is why "Shalaxys" takew so long to "warm" up?

[Ivor_E_Tower]

Sensor on radiator is almost certainly for the cooling fans. There should be at least one sensor on the block and/or the thermostat housing for the temperature gauge and engine ECU.