Coolant Overflow???

[Brydakidz]

Been having a problem lately with my 99 SHO.

After driving and my car for a decent amount of time and getting it all warmed up it tends to overflow the radiator coolant out of the overflow tank. But the strange thing is that it will only overflow after the car is turned off. The car doesn't seem to be overheating as the temperature gauge reads normal with the gauge in the middle.

If I turn the car back on while its overflowing, the overflow stops and the level goes down.

I double check all the time that the level of coolant right where it should when I fill it back up.

I replaced the cap and I even pressure tested the system and its holding pressure. I also replaced the thermostat.

This is really puzzling to me.

Any input would be much appreciated. Thanks.

 

[SHOZ123]

Sounds like either the cap is bad or the threads are stripped on the tank.

A new tank comes with the cap.

 

[tqmx1]

Sounds like either the cap is bad or the threads are stripped on the tank.

A new tank comes with the cap.

Unless you get one from FoMoCO, them suckers are cheep skates.

Need less to say I found out the hard way

 

[Brydakidz]

Thanks!!

That did the trick. No more overflow.

The threads on the tank were warped and therefore couldn't hold the pressure.