Overflow tank boiling

[IPD]

Not my 3/s, but probably similar for any/all cars. Fluid in my overflow tank is boiling. I've heard it bubbling previously, but tonight steam was actually coming out when I parked. Not good. Nothing coming from out of the radiator though. Wierd thing is, I drove it from AZ to UT without any issue. Fan clutch was replaced & radiator was flushed previously. Any ideas?

[R/T93]

Mine bubbled this summer at 10-11k ft when I had like 100 dead butterflies blocking my rad...

[Chris@Rvengeperformance]

I wonder if your radiator cap is bad?

[CoopKill]

^^ ^^ ^^ ^^ ^^ ^^ ^^ ^^ ^^ ^^ ^^ ^^ ^^

[stealthee]

Yeah, bad rad cap would not let the system hold enough pressure. It could also lead to coolant evaporating past the seal.

[ICPREY]

Not my 3/s, but probably similar for any/all cars. Fluid in my overflow tank is boiling. I've heard it bubbling previously, but tonight steam was actually coming out when I parked. Not good. Nothing coming from out of the radiator though. Wierd thing is, I drove it from AZ to UT without any issue. Fan clutch was replaced & radiator was flushed previously. Any ideas?

Same thing happened to my wife's Ford Taurus, it ended up being a head gasket issue. Start with the simple stuff like the radiator cap first.

[HLxDrummer]

I'd check/replace the rad cap, check your coolant's water/antifreeze ratio, and look at the oil/coolant for signs of contamination first. Was your temperature gauge going up at all?