bubbles in expansion tank?

[fax0815]

Hi,
just a quick question which I cant figure out at the moment. I´m having airbubbles in the expansion tank, constant once its warm and it does overflow a little one you race it.
The waterhoses don´t feel like they are at 0,9bar. So I thought rad cap I´ve changed the rad cap for another one in unknown condition and it does the same.
Rad cap seat in radiator hasn´t got any visible damage.
Might buy an uprated rad cap like on all my other cars?

I don´t suspect headgasket since the engine is 3000km old, and the head was skimmed and OEM gasket was used.

It still does have all the original Toyota waterhose clamps everywhere.

Am I missing something?

[jondee86]

When you put your nose in the expansion tank while it is blowing bubbles,
does it smell like exhaust fumes ? Any water in the oil or oil in the water ?

It may be possible for air to leak into the cooling system on the suction side
of the pump while the engine is running. But if that was the case, there
would be coolant leaking out when the engine was switched off.

Cheers... jondee86

[Dave W]

Depending on the size of the leak in the cooling system you could possibly see white smoke in the exhaust.
Probably the best route is a compression or leak down test. It could possibly be a crack in the block or head. You could try re-troquing the engine head gasket. But since you have to pull the cams, it is almost the same amount of work as installing a new haed gasket. If do re-troque, only loosen one head bolt at a time. Using a center to out board sequence, using a troque wrench. Dave W

[fax0815]

Went to a garage and we co2 tested the coolant, and it look like its head gasket, chracked whatever...

[Ivan141]

That's too bad, hope it really is the gasket and not a crack anywhere (had that once, turned out to be a cracked block, in a daihatsu mind you).
If the gasket is ok, dont replace the head blindly without having it tested first.

[fax0815]

(04-25-2017 03:19 PM)Ivan141 Wrote:  That's too bad, hope it really is the gasket and not a crack anywhere (had that once, turned out to be a cracked block, in a daihatsu mind you).
If the gasket is ok, dont replace the head blindly without having it tested first.

Whouldn´t do that, there is a days worth of headwork in the head.