Hiya Im having an issue with my Temp gauge. I'll be driving along and suddenly it will build all the way up to rhe red zone. At the same time the heat will cease(blower continues just no heat). I have felt the radioator cap and upper hose.. both seem normal. after a short while the needle will drop back to normal levels, Heat will resume, and all is back to normal. Anyone have any Ideas?

 

Did you just service your radiator?

This is whats happening...you have air in your radiator system cause we have reverse coolant flow...this is how you get it out

Take off radiator cap with car off and cool. Start the car. The coolant level will drop. Go ahead and have the heat turned on at this time also. When the level of coolant drops, fill it up pretty close to top. IT should drop a few times, and add till its full. Then you will see it start to rise until its about to spill over. PUt back on the cap.
Then open the bleeder valves one at a time until you see coolant coming out with no bubbles. Those are located right above the thermostat on two diff hoses I believe. They are brass bleeder valves.

If you didnt just have anything done to your radiator, your thermostat may have gone south. Replace that, and then do what I just said above.

 

roger that had my radiotore flushed and filled about 3 months ago. will replace them and refill/bleed hope that takes care of issue thanks! will post if I have more probs.

 

I too think its a problem from air in the system. Good luck