off the wall temp readings

[thumpida]

ok it is currantly 46 degrees farenheit outside. driving my 89 mtx with no overflow tank for my radiator im driving about 35-45 mph and my engine says its ice cold. when i pull a stop sign it climbed to the o in the 5 seconds i was sitting there. pulled out went up to 35 and it dropped back down to cold in rougly 2 seconds. it did this at every stop sign. i was only driving for about 6 minutes so i cant beleive it really had a chance to get too warm. any thoughts?

 

[Slo-Sho]

I'd say check your coolant level. You most likely have plenty of air in the system as well. Overflow bottles are very cheap, no reason why you should not have one.

 

[sdpatt]

I'll bet that you radiator fan is not operating. ProjectSHO89, I believe, has previously posted a troubleshooting procedure for this condition. You may want to search for it.

You must have an expansion bottle or you will be losing fluid every time you run the engine. That is not an overflow bottle, but an integral portion of the cooling system. Replace it. Quickly.

 

[Mike Kopstain]

Verify that your thermostat is operating properly.

Also understand that air in the system is a recipe for trouble as there are hot and cold spots in the motor when air is present. The hot spots are HOT and the cold spots are significantly cooler. Too much expansion and retraction for me to be able to relax.

 

[SHOZ123]

You need the overflow tank. Engines are designed to have a closed coolant system. Without an overflow tank the coolant will be spit out as the engine heats up and when the engine cools air is drawn in. This is a sure way to cause a slow death for a mixed metal cooling system.