Expansion tank

[Wigiz]

Hi,I'm looking for a bit of advice, I think theres an airlock in the engine somewhere, when van as been stood a day or two level will drop in tank but if you remove the cap the coolant rises back to the proper level, also when I have seen like pin hole bubbles rising in the tank when engine is running, any help much appreciated, thanks.

[motorman116]

Check egr cooler

[Wigiz]

Thanks for the reply, just been looking through the records and the van has had a new oil cooler thermostat fitted about 2 months since, when the new one was fitted could this have introduced air into the system, there not excessive bubbles it’s more like pinhead bubbles coming to the surface.

[knobby1]

Thanks for the reply, just been looking through the records and the van has had a new oil cooler thermostat fitted about 2 months since, when the new one was fitted could this have introduced air into the system, there not excessive bubbles it’s more like pinhead bubbles coming to the surface.

Would help if you told us what vehicle you have..?? Mk6, Mk7..?? FWD, RWD..??

Oil cooler thermostat has nothing to do with coolant, nor EGR cooler.....it uses oil temp to open and let oil flow through the oil cooler.

Lord Knobrot

[Wigiz]

Sorry it's a mk7 2.4 tdci rwd model, cheers

[knobby1]

Sorry it's a mk7 2.4 tdci rwd model, cheers

EGR cooler goes round behind the cyl head on the 2.4...pig of a thing to get at too.

Lord Knobrot

[karl]

join the hoses together for peace of mined, if it still does the same you need to start looking in other places