Erratic cooling system

[George]

I've got an 89 Daytona with a 2.5 liter motor. I replaced the radiator and
thermostat. Now the temperature gauge constantly floats up to about mid way and down to almost cold while driving. The heater barely works also. It stays full of
antifreeze. Any ideas? Any help would be appreciated.

[Gary]

Bad thermostat. I've had more than one fail right out of the box.

[new and old mopar man]

HELLO, these cars are prone for having plugged heater cores which will make the guage fluctuate but if you dont have any heat then try the stat first DAN

[PRO]

This car has a vaccum operated heater control valve,when the gauge reads normal temp feel the htr hose just past the valve is it hot? if not it could be bad.Is the drive belt to the w/p in good condition? it could be slipping periodically,does it squeal? You could have an air lock in the block,try filling the block thru a heater hose near the thermostat housing,use a small funnel in the end of the hose.To be sure check your themostat in a pan of boiling water it should open right up. What temp stat did you install? A 160* stat in extremely cold weather at hiway speeds will do exactly what you stated your symptons are.Also too high of a concentration of antifreeze will cause wierd symptons use a 70/30(anti/water) mix max.Hope this helps you....PRO....

[moparscott]

Your cooling system might be air locked. When you fill the radiator up you have to remove the plug that's in the water box (behind the thermostat). When coolant flows out of the hole in the water box then you just screw the plug back in. I would replace the plug with a brass one too as the steel ones react with the aluminum head and become very difficult to remove. Scott

[keith3123]

Originally posted by George:
I've got an 89 Daytona with a 2.5 liter motor. I replaced the radiator and
thermostat. Now the temperature gauge constantly floats up to about mid way and down to almost cold while driving. The heater barely works also. It stays full of
antifreeze. Any ideas? Any help would be appreciated.

THERE IS AN AIR POCKET TRY JACKING THE FRONT OF THE CAR IN THE AIR AFTER IT IS HOT TO SEE IF IT WILL ESCAPE ALSO USE A MOPAR THERMOSTAT I HAVE NO LUCK WITH AFTERMARKET THERMOSTATS DO NOT CHANGE TEMP RANGES BECAUSE IT COULD CAUSE DRIVEABILTY PROBLEMS

[kpzbee]

From what I read, I'd bet your headgasket is leaking internaly - VERY common! Air (read compression) is leaking into the cooling system causing the "air lock" around the thermostat which then won't open cause it's not in a liquid & is the highest point, then gets hot - after some coolant gets to the stat, it opens & drops the temp. Sound like whats happnin? Hope this helps


ps The no heat is the same problem, beacuse the heater core sits up high in mopars & also gets air locked to.

[This message has been edited by kpzbee (edited January 28, 2000).]