Mk3 heater temperature control

[1 gti]

NEWS!!! New thermostat fitted and went for a spin to test and all was well until the needle reached 100c!! No fan coming on, no over heating and Water in the expansion tank weren't bubbling and the engine feels the normal temperature. Dodgy needle in the dash? any help would be appreciated before I decide to torch it!! Lol. Must remind you it's a diesel if it makes a difference. Cheers

[Deano2711]

Temp sender ??

[Wayne]

As Deano said, replace the temp sender.

[thai-wronghorse]

Air lock maybe?

[1 gti]

Went out this morning and the needle was on 70 and overheated on me, flashing light on dash. Free car anybody? Where's the temp sender located? Cheers

[Deano2711]

Located at the top right hand corner of the front of the block. The top hose goes to it and it will be a coloured part. Let the car cool down beforw changing and its a two minute job to change.

[Wayne]

Went out this morning and the needle was on 70 and overheated on me, flashing light on dash. Free car anybody? Where's the temp sender located? Cheers

Sounds like to me that it has an air lock.

[thai-wronghorse]

That's what i reckon as well.

[Gavv8]

Try running it from cold with the heater on full and the cap off the expansion tank, keep squeezing all the hoses to get the air out until the engine starts to warm up then put the expansion cap back on but keep the heater on full and keep your fingers away from the cooling fan in case it comes on suddenly.

[1 gti]

Overheated on Saturday and the radiator was stone cold, just bought new waterpump. Hope this works, nothing but bad luck last week. Keep you posted