alright so heres a little back round on the car (1997 30th camaro z28), i bought it about 2 weeks ago for a 1000 running with a 6speed, and 373s in the rear other than that it was all stock. had a blown head gasket..

fixed head gasket and also noticed a little lifter tick so pulled the valve covers and adjusted them all. so now it runs graet at idle and at high revs. diesels a little after turn off but found a code for timiing being advanced so im pretty sure tha twill fix it.

but ANYWAYS back to what my new problem is. their is pressure that is buildign up in the colling system somewhere causeing it to over flow without running hot. has new water pump, CURRENTLY removed thermostat so get some better flow for now.

any quick suggestions ot why it would be building up pressure??

oh yeah it will take about 5 min driving before i notice the heater go cold from losing to much coolant and it will never over pressure at idle... no ore smoke out the tail pipes either.

 

I would install a 160 thermostat and new radiator cap and go from there.

 

oh yeah i forgot to mention that the radiator cap before was shot o hell and i have a 160 ts in my car so i ran it in the camaro and still no luck, it was running cooler with no ts at all. it also has new radiator from which the previous owner installed.. what else besides trapped air could be causing the pressure build up.

i just got done driving it and when i got home, after a 7-10 min drive i opened both bleeder screws and air was coming out for about 8 min! how could that much air be getting in their??

any help would be greatly appreciated

 

Compression getting into the system (not what you want to hear, I'm sure).

 

how does compression get into my cooling system. im guessing its not very good. but could a bad valve adjustment do that??

 

bad head gasket

 

i had a funky issue similar to this after installiing a water pump. the 2 o-rings on the drive did not seat right putting pressure on the wp bearing and for whatever reason the pump would draw air, cause an overheat issue due to low coolant level but never was there evidence of a leak anywhere. i'd have to refill the system every 1-3 days. removed the o-rings (they were squashed flat) and installed new wp, never had the problem again. but in your situation it sadly sounds like head gasket. just giving you an option to check before tearing the heads off again.

 

Ditto that.....grab a cooling system pressure tester, put it on the car when cold, pressurize the system to around 8 psi, fire up the engine, if compression is getting into the system you may see the needle bounce wildly or vibrate. If the leak is bad enough...it may not hold pressure. According to my pressure system manual...a normal system should hold close to cap pressure for at least 2 mins without leaking down(my cooling system held it for 30-40 mins...never did go down).

Normally, the needle should be steady and will go up smoothly as the temp goes up.....if my Z was together I'd video it. Just don't let the pressure go over the cap rating.....I doubt that coolant will be able to press past the seal of the tester to relief pressure......you could actually cause a leak if it goes above 18psi....I think that is the cap rating.

I had to use a pressure tester to troubleshoot my cooling system before my CC503 buildup. I was losing coolant and could not figure out where it was going...I kept getting the low coolant light...and the radiator was low. I would fill it up, several weeks later...same thing....well I found where the coolant was going....into the overflow tank. I had extra in there(I never bothered checking the level first time...just assumed it was empty because the radiator was low...duh...mistake)...and the problem???? The pressure cap was not sealing like it was supposed to and every now and again was not allowing the coolant to suck back into the engine, thus leaving it in the overflow tank and pulling air into the system.