radiator coolant bubbles
 

Is there anything other than a head gasket leak that would cause the coolant to bubble?. Engine was just rebuilt this past year.

Re: radiator coolant bubbles
 

cracks. Was it pressure tested before the rebuild? I would re-torque the heads and if that doesn't help might try a coolant sealer.

Re: radiator coolant bubbles
 

I would add a large bottle of Barr's block sealer. Run the engine
and get it up near 200. Shut it down and let sit over night with
the cap on tight. I have seen lots of bubble problems, water out
the exhaust and it fixed 99% of the problems. I use the type with
copper flakes. G.M.