Hi I have Subaru Impreza 03 wrx which when started and warmed up the header tank can be heard boiling away and engine will heat up very quick but never overheats water is circulating and already tried air lock ,thermostat ,caps .running out of ideas and need to make a decision any1 can help ?

 

Personally I'd call my garage and ask them to come and get it so they can check it out before you do anymore damage.

 

forgot to mention when the car has been drivin for long time or drivin hard the steam will come for underneath .

 

Get it to a garage before you cause a bigger (costlier) problem!

 

Get a sniff test done to determine whether it's a head gasket. Is there any white smoke from the exhaust? Oil in the coolant? Mayo residue in oil cap? Does your heaters blow cold when set on warm? Does the bottom radiator hose feel squishy or cold when engine is on?These could indicate a head gasket but not guaranteed....as already mentioned best to get it checked out by an expert. It could be something simple like an airlock or the coolant cap seal has had it etc.

 

No mayo residue or oil in coolant . Heaters are hot when suppose to be .av had a mechanic on it changing thermostat yesterday and he still says sound like a head gasket . It's like the smoke is coming from in the heat shield under the car still no overheating . Thanks

 

Header tank boiling noise may well be the air lock in the coolant.Does it sound like it is coming from behind the dash?

Imprezas are very hard to fill with coolant.See the many posts on here regarding the problem.

 

No you can hear the noise coming directly form the header tank but the steam is coming for underneath

 

OK, I see.Thanks for that.

It's just that coolant air locks are such a common problem.

Good luck finding the issue.

 

Could be a very small hole/split in on of the coolant pipes spraying coolant onto the hot exhaust when hot & under pressure.My legacy did the same & looked like Thomas the Tank Engine coming down the road.

 

Havin another go at bleeding it with help from are mechanic here's hoping thanks

 

No lucky with bleeding and try with a funnel on radatoir so was higher than header tank defo head gasket bubble never stop or settled . Has any1 ever heard of blue devil liquid for head gasket sealer ???