Cooling System

[Jeepjeff859]

Every time I go driving the temperature likes to climb rapidly it goes all the way into the red until I turn the heat on, then it goes down.

 

Should I go get a new thermostat or could it be a bad sensor or something? Or both?

 

This thing seems to have many electrical problems

[ParadiseMJ]

I think you have bigger issues than a faulty t-stat...unless it's stuck closed.  If it were stuck open it would take a long time to heat up...even to normal operating temps.  If, indeed, it's stuck closed a thermostat might be at fault.  Since that's the cheapest and easiest part of the cooling system to fix, I'd go for it.  Be sure to get a quality 195 degree t-stat from either the dealer or NAPA.  Cheap-o Auto Zone or O'Reilly's t-stats are crap)

 

Check the pressure bottle and cap for cracks.  The thing shouldn't ever get to the red when you just "go out driving".  Does it do it under all conditions? Things to check:

 

operation of fan clutch

operation of aux. electric fan

condition and level of coolant

condition of oil (for coolant contamintion)

 

Check those...report back.

[Eagle]

Every time I go driving the temperature likes to climb rapidly it goes all the way into the red until I turn the heat on, then it goes down.

 

Should I go get a new thermostat or could it be a bad sensor or something? Or both?

 

This thing seems to have many electrical problems

It sounds to me like you need a new radiator. The fact that the temp goes down when you turn on the heat is a clue. After all, the heater core is just a small radiator. If running coolant through that lowers the temperature, that pretty much tells us that the radiator isn't doing its job.

[metrictonner]

Ditto new radiator.  25+ years on original radiator means restoration not repair.  A shiny new aluminum jobbie did the trick for me after a couple years of playing around with EVERYthing else.

[oldseddie]

I found a late model aluminum radiator in my parts stash with place for renix temp sender. Runs much cooler than the brass 2 core.

[HOrnbrod]

so today i took off my valve cover and as i started to undo the bolts next to the throttle body coolant come up from the bolt holes and into the cylinder head, is this normal?

 

also whats a good way to clean the engine of the coolant, i drained the oil as soon as it happen in hopes of taking most of the coolant out

It's more than a radiator problem. Recommend you do a coolant system pressure test