jachunter

Background:
94 GT
224k miles
Changed thermo 90 days ago to a 180


Problem:
Car takes a long time to warm up...When it finally does, the needle on thermostat goes from C to H very very quickly, It darn near pegs on the hot side. Then, and only when I start driving, it will come back down the C side and runs cool.

Also the hot air doesn't work when I am sitting still, but when I start driving again, the air will get hot again. Very strange to say the least. Furthermore, the car takes forever for the air to get hot when i want heat!

Anyone else had this problem ? Are the problems both being caused by the same thing or are they seperate issues?

The car generally runs a lot hotter than it should even when I am moving constantly. However stop and go, it really runs hot.

I recently had to replace a radiator hose that busted and my only thinking is that I may have a air pocket?

Any thoughts ?

1BADASSLX

water pump!

Suspect

if its the wp then u should see some water/coolant from the weep hole. if not id try burping it. take the temp sender from the lower intake off and fill it from there.

Low_5.0

take your Rad cap off and see if the fluid is circulating..if not it's likely the water pump...if it is moving u might have a Air lock....gotta burp it!

jachunter

90 bucks deep now. same problem

New waterpump.

Refilled the radiator, left the cap off and started the car...It never burped and started to get hot again.

My only thoughts now are...radiator clogged (water does get purty rusty) or thermostat not opening...

What do you think?

Even though the car is running hot...NO hot air, only cold air. Upper radiator hose cold, obviously no fluid running through it.

Gonna check the stat tomorrow on the stove and if that is fine...replace radiator.


The fan not kicking on wouldn't cause no hot air right!?

WesDe

I agree. An air pocket would cause sudden increase decrease in temp. Try to empty coolant and raise the front before you fill it up again. You can also take out the thermostat and drill a very small hole on the top. That would let coolant through and eliminate air. Try it and see what happens.

grabbem88

i think stat is bad.

stanglx2002

it could be a few things and start from the cheapest to the most expensive:

temperature sending unit
thermostat (if you replace this put in a 180)
waterpump