air bubbles in expansion tank

[milkyb70]

Bought my 3.0 1kz about a month ago unknowingly with a cracked head.think it may have been full of radweld or such like.any way bit the bullet and changed the head and gasket.water pump was ok.flushed radiator no leaks.got everything running ok went for a drive about 40 miles until temp gauge started to climb but never in the red.now I have bubbles in the expansion tank after a few minutes running is when engine is warm.Please dont tell me I've cracked the second head.engine block wasn't checked for leaks etc but old head had visible cracks between valves. thermostat and radiator cap have been renewed also timing belt.i'm at wits end with this please help.

[Surfer Ross]

Where did you get the head and gasket? Genuine Toyota, Roughtrax and the Engine Company seem to be the only viable options. If you bought from Ebay, you're playing Russian Rouellete.

If there is foam inside the radiator cap (not the expansion tank), you can be pretty sure that the head is cracked or the gasket you fitted wasn't up to the job.

I paid about £1400 all in for the head change on my 3rd Gen 3.0, £1k of that was for parts.

[milkyb70]

air bubbles in expansion tank

The head was from e bay.without taking the head off I can't blame anyone as yet.i blanked off the egr at the exhaust side but left the small rubber hoses attached , vacuum and suchlike.also the engine block wasn't checked when the head was off because I saw the old head was definately cracked.the surf starts and runs fine no steam from exhaust ,doesn't seem to lose water,has a new thermostat and radiator cap.the bubbles appear when the engine is warm maybe one every second,not like a kettle boiling.maybe I'm thinking about the worse case scenario.i like the surf,being 18 years old it feels very smooth no rattles or bang unlike the 98 shogun i had before

[shokenore]

Get a combustion gas check done.

[muddle]

Shogun shite, have a compression check done and a coolant gas check, was the system bled correctly? Make sure when bleeding that the front and rear heaters and on full hot. You can also try leaving the cap off overnight. Don't forget to put it back on tho.