Header tank bubbles
 

Hi all

Quick question about coolant bubbles in header tank

I've replaced rad + hoses, I re filled via rear most hose on header tank to turbo - so back filled.

Started car with header cap off, and allowed to warm, gently gave it some revs up to about 2500, and I noticed that there were a lots of tiny bubbles coming through into the header tank when raising the rpm over about 2500 . The stat hadn't come on yet, so I'm praying its just trapped air?

Is this normal?

cheers

put the cap on and take for a gentle spin. let it cool and look at the level. if its dropped top up and go for another spin. check again once cooled. also look at the expansion bottle on the passengerside to see if its dumping coolant. if it was all fine before and uve filled like you said its probably fine.

ok so i went out for a spin, gave it some beans and there is no coolant being pushed out the expansion bottle (one near battery) however i noticed when turning car off the level in the expansion bottle drops - as tho the coolant is being sucked back into the header??? its only a tiny but but is this normal?

cheers

Yes mate that's how it works. When the coolant is very hot it goes into the expansion and as the coolant cools it sucks it back into the system. Designed that way so it can expand and retract without loss of coolant or too much pressure. It is normal to sometimes have to add a little too.

I wouldn't worry unless anything else is wrong.