The temp gauge on my 2001 caravan is now going from cold to hot shortly after starting up my van but the engine is not blowing heat. The warning light is coming on. The temp gauge starts to drop, but then goes back up.

Van isn't leaking and the rad hoses feel full.

Fan is kicking in and running.

Is the t-stat gone or something else?

 

i think bad t stat but they ussually fail open so ya show colder temps

 

Welcome to DF
Could be the T-stat or blowen head gaskets. Try a T-stat first.

 

Thanks for the help.

After two trips to the garage, the problem still isn't fixed.

The dealer first replaced the t-stat and the fan relay.

Things seemed ok for 3 weeks but there was no heat.

Problem returned. Dealer checked the head gasket and everything seemed fine. Dealer checked the water pump, but said the pump is working ok. Checked t-stat and it was working as well.

Mechanic said that there seemed to be too much fluid in the resevoir and that ther must be a blockage in the system. Replaced the rad, and things were ok for about 100 miles. Heater stopped blowing heat and then the temp gauge started spiking.

The problem only happens when driving the van.

Any suggestions

 

Is the fan in the fan module coming on?