New Thermostat Required?

[The_Laird]

My temperature guage is a little erratic and wavers around between about 70C and 90C, but rarely gets as high as 90. Does this suggest a knackered thermostat?

If so, where is it and how easy/difficult is it to replace?

Or is it something more sinister?

[PsYcHe]

Could be thermostat.. could also be temp sender which is a much easier job..

Ben can tell you better today.

[notorious]

If arrow is unstable and "jumping", then it's sender or instrument panel issue since coolant can't change temperature that fast.

If in long traffic jam it gets up to 90 and then slowly drops to 70 when you drive faster, then it's thermostat. In other words, if your car only warms up to full 90 when parked or when you drive very slowly, then it's thermostat in my opinion.

Changing thermostat on 4.2 and 3.7 requires removal of cambelt (not sure about 2.8 and diesel engines). If cambelt wasn't done recently I would suggest to change water pump, cambelt and tensioner together with thermostat.

[The_Laird]

Ouch - my wallet hurts!

Had the whole lot done at A4 Audi in Clydebank.

Now running at a steady 90C. Thanks guys

[notorious]

Did they confirm is was thermostat?

[The_Laird]

Originally Posted by notorious

Did they confirm is was thermostat?

Yes, it was duff