draco

After running my car around town for about an hour my temp gauge reads just under 220. This is normal driving in about 75 degrees weather. The car runs fine and every now and again the temp will drop to the normal 110-115 range.

The real problem is when I stop my car and turn it off. It makes this bubbling boiling sound from underneath the hood. It is full of fresh water//coolant mix, and it has a brand new thermostat, and the water pump is less than 2 years old. She is a 3.1v6 auto.

Thanks guys...

five7kid

iTrader: (14)

220 isn't unusual for our cars.

Whitchman

But is the bubbling unusual for a temp of 220? I know mine has only bubbled when I was up around 250.

sofakingdom

iTrader: (1)

Yes it is normal..... for a car that needs a new radiator cap.

Replace that and see if it shuts up.

rmmstnr

Whoops, wrong temps. I meant at 225-230 or so it bubbles occasionally.

Supervisor42

Sofa is right. Do the math. 50/50 antifreeze solution under 13 PSI will not boil below 220°. If anything is coming out of the cooling system when stopped below that temperature, the cooling system (read: radiator cap or neck) is not holding pressure. This is probably the most often overlooked problem.
And don't bother with a "cooling system pressure tester" They mask radiator cap and neck problems and are just for locating leaks.

Apeiron

It's normal for the coolant to be 220 F regardless of the condition of the cap. It's not normal for the coolant to boil below 260-270F unless the cap is bad.