As the engine warms up the temperature gauge goes up to 220 fine but then starts to move towards the red. Some times it stays in the red or slightly below it while I am driving and then suddenly drops to 220 again. The needle also vibrates quite a bit. It keeps going between 220 and the overheat mark. Just to be sure I checked the engine with an infrared thermometer and it reads about 220. The air dam is all intact and the coolant is flowing. Is it normal for the sender unit on the engine to give trouble.

 

they can fail... sometimes in the strangest of ways. my oil sending unit did some strange stuff one time, changed it and life was good. i'd change your sender, but check your wiring, too. make sure it's all intact, not frayed, etc. probably good, but you never know.

KAM

 

If your motor is reading 220 that normal unless you have changed somethings. Like stat and fan mods, different chip. I believe the stock chip fan setting is 220 so sounds like your at stock setup and working as designed. You never said if the fan kicks on at 220, does it?

 

The fan is run off the engine so it is on all the time. I think that in 83 they switched to an electric fan. All the 82 engines had belt driven fans as far as I know.

Gerry.

 

Ok, if the fan is driven off the front of the motor and seems to not be cooling I would think it is either, stat, radiator core partly clogged, or a weak water pump. Per your description, most probable cause is thermostat.

 

Do you have a shroud around the fan to help with the air flow? Also check to make sure that your radiator hoses aren't collapsing on you.

 

Yes the shroud is in place. I suppect that it may be the sender unit. I am getting the loan of one of those infred thermometers to measure the engine temperature. Where is the best place to take a reading?, I was thinking from the hose coming from the radiator.

 

The engine itself, Also you might try moving the sending unit wire away from the engine so you don't get a false reading on it.