It takes an age in cold weather for my 2.0L petrol Octavia I to warm up, I have a 25 minute drive to work and it is only just getting up to temperature by the time I get there...

Before I go all old skool and stick a load of tin foil over the radiator, is this normal? Should it take this long to warm up or is it more likely that the engine thermostat is stuck open?

Is it easy to check/replace the thermostat?

Cheers

I'd hope not. I've got a diesel, and it warms up inside of 5 minutes (about 4 miles), despite its much lower heat rejection.

If you've got air con, then if that desperately needs a regas, that may also have a negative effect on warmup time, but my thoughts would incline to a stuck-open 'stat as the first cause.

Have you checked under the oil filler cap? if its the thermostat you usually get like a white mayonaze forming. My old Corsa had this problem. i thought it was the head gasket but it turned out to be the the thermostat. You could try putting in thinner engine oil maybe

It takes an age in cold weather for my 2.0L petrol Octavia I to warm up, I have a 25 minute drive to work and it is only just getting up to temperature by the time I get there...

Before I go all old skool and stick a load of tin foil over the radiator, is this normal? Should it take this long to warm up or is it more likely that the engine thermostat is stuck open?

Is it easy to check/replace the thermostat?

Cheers

Classic symptoms of a stuck thermostat, & yes it's a pretty easy job to replace.

Have you checked under the oil filler cap? if its the thermostat you usually get like a white mayonaze forming. My old Corsa had this problem. i thought it was the head gasket but it turned out to be the the thermostat. You could try putting in thinner engine oil maybe

The car has had the mayonnaise under the filler cap for ages, my dad owned the car before me and he said that it wasnt a sign of the head gasket going because he had had it checked, it must have been the thermostat that caused it, in which case the thermostat has been bust for years!

I guess the mayonnaise is caused by the crank whipping up the cold oil?

I'll check and replace the thermostat this weekend, thanks for all your replies

They mayonaise is caused by the car never really getting up to temperature. Change the thermostat and it should soon disappear after a run. It does sound like its been broken for quiet a while, so get it changed and you should see an improvement in your MPG, your comfort and the mayo go away.

As Manny says about the cause. What actually happens though is that water vapour condenses and mixes with the oil inside the rocker/cam cover.

Banzaiman, where did you get the "lighter grade oil" theory from? I've never heard it before.

Well my Theory behind that was, If its a thinner oil sureley it would take less time for the car to heat up possibly :wonder:

Holy thread resurrection!!

I can't see why the oil grade should affect the warmup time significantly. Mineral oils mostly have similar thermal transmittance to each other. Any difference I'd expect to be due to the work done in pumping the oil around, so higher viscosity oil will make an engine warm up faster, but that's not significant (based on warmup being longer in Winter).