new t-stat still have old probs. wtf?

[88GT4u2nv]

spent like 3 hours putting in new 190 t-stat to try to solve heater probs. well after stripping the hole for the lower bolt, and getting that worked out i got it all togeather. flushed my htr core by putting a hose up to both in/out ends of the core and bled the system of air. i went to take it for a drive. ALAS the heater was working. this morning i warmed it up for 10 minutes just to get in to cold air blowing from the vents. my temp gauge is all over the map, heater blows warm for about a min and a half, then will blow cold for a min and a half, all the while my temp gauge goes up and down.

on my work break i open the rad to find it way low on coolent. filled it and the heater worked a little better for a couple minutes then i had the same prob. i got home...same deal, rad was a little low. seems like i might still have a little air in the system.

ps. i used rad flush as well, and im still getting a little foam from the flush ****.

whats going on with this thing...i just want heat!!!

 

[87'GTstang]

The best way to bleed the system is take the cap off, start the engine, let it run for awhile until fully warmed up. Once you think the t-stat is open, rev the engine a few times to see if the coolant goes down a lot and take note of air bubbles (you might also have it spew out a bit). Main thing is to make sure you get all the air out.

If you keep losing coolant after a while, check the usual, look for any leak whatsoever, check your oil for the classic mocha milkshake, if you still are losing it - may just be a blown headgasket coming up.

edit: Oh yeah, without a constant supply of coolant flowing through the heater core, there will be no heat transfer possible -> so no heat out of your air vents will be possible.

 

[vristang]

I would start with another system flush. It sounds like you still have flush fluids in the system which are contributing to air pocket formation. Air pockets will prevent any flow of coolant (which can cause lowheater temps, and high block temps). Not until pressure is high enough to overcome the blocking force of the air pocket, will the coolant begin to flow. Two ways that may work, Increase the press of the rad cap. This may have negative affects if the system is old and likely to fail with the new pressure. Or rev the motor a little. A quick blip or 2 of the throttle can produce enough pressure to break up the air pockets.
This time give a good rinse of pure water. Then when satisfied the system is clean, add in the coolant.
Using a jack to raise the rad cap end of the car can help purge air from the system as well.
good luck
jason


:Word:

 

[5spd GT]

Experiencing a very similar problem...subscribing.

 

[ss93cobra]

I'd have to agree with 2nd post. Sounds like you didn't "burp" the cooling system properly and have since gotten a good amount of air trapped in the system. Follow the directions in the above mentioned post to relieve the system of any trapped air pockets.