overheating problems

[JokersGrand]

Hello all, one of the newest here, but have been browsing a while.

Anyhow...I searched and found no specific help with my 2.3 DOHC.
Problem...she's overheating even AFTER head gasket replacement. Temps from 220 on up to red line. The curious part is that if I rev the engine in park or floor it and rev the engine that way, the temp gauge falls quickly to around 180* and then slowly rises back up. I replaced the thermostat and water pump when the head was off. Also, the head had a crack in #2 between one intake and exhaust valves. Was professionally welded, and a complete valve job performed, and pressure tested.
Do you think the thermostat is faulty or is there simply residual air in the system?
Is there a special coolant/air purging method for the Quad 4? I've read about the V6 models having an air relief point, but found nothing about the Quad 4.

Your help greatly appreciated.

[graden]

remove your t-stat . run to see if it still over heats. if it does .. i would tend to think your heads still have a crack in them some ware.

[JokersGrand]

Removed the thermostat, flushed the entire system and reinstalled without the innards. No overheating at all, actually never gets to operating temperature, only peaks at around 150 at the highest at a standstill and just barely off 100 while driving. Now I have to try and trust buying another thernostat that isn't bad. It was a little sticky after removing it. It was brand new.

Thanks graden for the help.
Jim

[JokersGrand]

forgot to mention...
there was a considerable improvement in low end response from the engine without the thermostat. Although, until it warmed up past 100, it would keep trying to quit running. Which it did several times, until I had to mother the throttle, then ran fine.

[pontiackid15]

Where was the thermostat located on your engine? Was it near the water pump? I have the same exact problem with my 2.3 ohc quad and its killin me. I just want it to run cool!!!!

[JokersGrand]

For my 1995 Quad 4 DOHC...The thermostat is located under the water pump, between the water pump cover and radiator outlet pipe. (held together by two 8mm bolts) When refilling the coolant (a cold engine), I disconnected the heater core hose from the inlet housing on the end of the head. I found that this was a good way to help purge the air through the heater core and as it filled, and went into the head. I would stop when coolant would start dripping from where the hose was connected (head side), then reconnect the hose and finish filling from the reservoir. After that, diconnect the air bleed pipe from the reservoir and set it above the fill hole. Reach around the throttle body inlet and pump on the upper radiator hose - you'll see the reservoir level jump around. (a light will help see the level) Squeeze the upper rad hose again and before you let off of it, put your finger over the air bleed pipe/hose end to stop air from being sucked back into it as you release the upper rad hose. Take your finger off when you squeeze it again, and back on the release. Doing this several times will "pump" the coolant from the head through the air bleed pipe (and out). I found by doing this, it greatly reduces the trapped air in the head. Reinstall hose after and fill reservoir to full cold level.

By the way, my overheating problem was fixed by proper purging and changing out the new thermostat with another new "Stant" brand one. The other was sticking even though it was brand new.

I'm still having the engine run erratically and die though. So I have to figure out what that is now. haha Seems that you fix one thing on these cars and another goes bad. Oh well...I don't mind problem solving. :D

[pontiackid15]

cars fixed, flush and refill and now it runs fine. I couldnt even get to the thermostat, so i gave up on it. Im probly guna have to take it to a mechanic when that goes................

[Mikes]

confirming the thermostat problems. What the new thermostat with another new "Stant" brand one would be? Anyone ?
Thanks,
Mikes.
...
By the way, my overheating problem was fixed by proper purging and changing out the new thermostat with another new "Stant" brand one. The other was sticking even though it was brand new.

...

[donalson]

did you test your old one?... all it takes is a pot of water and a thermostat

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