Bubbling overflow

[Madzman]

Hi guys, I just replaced my head with a used, milled head due to corrosion of the old one. I put 400 miles on it and decided to flush the coolant again. I notice coincidentally that where the rad cap plunger seals on the rad was rough looking so I milled the plastic there so it was smoother. I filled the system up and am now seeing bubbling into the overflow. Would a bad seal at the rad cap cause bubbling or do I have another bad head (or head gasket)?

 

[whatusername]

could just be air in the cooling system.. did u burp it after u filled it up?

 

[P-Funk!]

It is a bad head gasket or head. sry. Have a garage use an exhaust sniffer to be sure.

 

[whatusername]

I disagree there are numerous reasons why he could have a bubbling over flo a blown head gasket would be worse case scenario. First thing to do is look at your temps then burp the system.. Then make sure the fans are working Then thermostat then radiator then water pump then head gasket.. Process of elimination

 

[hornsfan10609]

My coolant overflow bubbles after I shut the car down and I don't know why. It could be your rad cap or air in the system as mentioned.

 

[Madzman]

Here's a follow up: after driving it for awhile and getting it right up to temp and them burping it, all seems normal now. There was probably some air trapped inside the engine. My guess is a hot spot was causing some localized boiling and creating steam.

I also bent the rad cap tabs up a bit and sealed up the rad a bit tighter.

 

[P-Funk!]

Cool. I am glad that fixed it!