2000 Running Hot

[EDDIE138301]

Put a new radiator on about 2 weeks. Everything running good. all of a sudden it started running hot today. Got it home, and noticed the reserve tank was completely full to the top, top hose from radiatior very very full and tight. took the cap off, spewed some, not much. started engine back up, got to half-way on the guage and then went back down to where it has been. water in the reserve back to normal. also, when the temp got hot, heater blowing cool air, back to normal heater was blowing hot again. I know these vans have a problem with the intake gasket, but I had that problem and had a new jasper engine put in 2 years ago. Even with the old radiator leaking, the guage never ran hot. Could it be the themostat sticking? Why would the reserve tank be full?

[GregA]

Hi Eddie,

It sounds like you might have some air getting into the cooling system, most likely from a head gasket leak. The additional pressure of this air, while the engine is running at higher RPM, would push the coolant into the overflow bottle and make the upper hose swell. The air in the system would also cause the heater to become cold when the air goes into the heater core.

I would have the coolant tested for the presence of exhaust gasses, or have a cylinder pressure test done to see if you can locate the problem, but I am guessing it is the head gaskets.

Sorry about that.

Take Care,

[EDDIE138301]

what would cause the head gasket leak? I had a new jasper engine put in 2 years ago because of an intake gasket leak? I am still under warr. for another year. I am not beleiving this. This van has been running good up until it ran hot yesterday and then I stopped it.

[diesel1962]

Hi.Like the other post said,have the engine checked out.If it is a head gasket,and you still have a warrenty on the engine Jasper should honor it. That is why I do not own any GM's with the 3.1 or 3.4 engine's anymore.Too many headach's.Have a good xmas!! Diesel 1962

[kidfam]

Either that or try bleeding the system both taps.

[RastusMcNair]

Another cheaper option is a new radiator cap. A bad cap will allow coolant to fill the reservoir but not draw it back when the engine cools. Rather the leaking cap draws in outside air.