Well guys I’m pretty annoyed right now. I got home from work and went to check the alternator belt because it was squealing a little bit. I looked over at the coolant overflow and saw it bubbling. Exactly what it was doing before I replaced the head gaskets. I’m pretty much at a loss right now, it’s a real head scratcher.
The heads and block both are perfectly flat and everything was cleaned up really well. I’m not sure what to do
Some thoughts -
Need more facts to help diagnose.
1) Does it do it when cold and just started? (More concerning.)
2) When warm is it continuously running to the overflow? (Never really stops.). Or does it raise the recovery tank say 2 inches and stop.
3) When did you last replace the thermostat?
4) When did you last replace the radiator cap and did you go with a 13lb one? Which allows/blocks that from happening.
5) What temp is your coolant when it starts to happen?
6) What material is your radiator? (Copper, aluminum, aluminum with plastic sides?
7) Did they magnaflux the heads?
Need these facts to come up with suggested next steps.
I would watch for a couple days as you just put it all back together. May take a few drives for the coolant to equalize in the radiator. (Providing it’s minimal bubbling not try to blow up your radiator.)
Also the the overflow is there to allow for expansion/contraction. When running or when off, so perhaps this is not a issue.
I would also put a new radiator cap on and make sure it seals well against the radiator mouth down inside. Perhaps it is not sealing or has the right release pressure and coolant is coming and going with engine temp due to a bad, wrong pressure, or not sealing radiator cap. Also buy, rent (Auto parts store.) or borrow a radiator pressure tester and see if the pressure fluctuates (Because of compression or exhaust stroke.) or just slowly rises.(Don’t let it get past 13psi.)
Let us know.