I am posting this for a friend of mine who is having a problem with his camaro. He has a 93 z28 mostly stock under the hood. He has been having overheating problems. I know he replaced his thermostat a few times in the past year and it keeps happening to him. I mentioned to him about bleeding the system the one time when it over heated and we did and the thign never stopped shooting air out. But his dad told him to stop and just let it sit until he looked at it. He now thinks he has a blown headgasket. He is also saying that someone said it could be air in his actual engine not just in the coolant lines. And they are saying it is because we bleed it when the car was so hot? i dont know i just am curious if when we bleed the air out could we of messed it up worse? i dont think we even bleed it fully .. it never shot out any fluid at all from the bleeder screw. and he said he isnt even sure if they bleed it after they changed the thermostat.

 

is the air dam in tact and functional?
nothing blocking the raditor? IE plastic bag
do the fans ever come on?
proper water to cooling fluid ratio?

I'd drain and flush the system, leave the bleeder screw(s) out while refilling until liquid starts coming out.

Cover that opti up!

 

Changes in antifreeze has been known to cause problems...Maybe a clogged radiator...the 1993 LT1's used an old style anti freeze that had both rust inhibitors and stop leak;- over time the raditor is exposed to many different metals, water pump changes and perhaps the wrong radiator flush chemicals. This stuff combines to clog up internally in the radiator. It may need to be removed and a new one put in or have the existing one pressure boiled - checked for flow and leaks by a radiator specialty shop and reinstalled. Obviously new thermostats won't help.

 

Define "overheating"..... how hot does it get (numerical reading), and under what conditions - idle, low speed, high speed, all the time?

 

If while bleeding the cooling system it "never stopped shooting out air" then you still have some bleeding to do. Get the system fully bleed and then let us know what it is doing.

 

thanks for some help guys.. like i said i was just posting something to try n help my friend out. it was "overheating" randomly.. but mostly when he would be driving for a few miles. I mainly was concerned with him thinking we made it worse when we tried bleeding it the one day when it was overheating. He tried telling me that his dad talked to someone and they said we might of screwed it up worse and got more air inside or something i dont know. I just remember opening the bleeder screw one time when it was overheating and it was shooting so much air out and it never stopped.. and we just closed it back up and then i never seen the car again after his dad looked at it.

 

i changed my coolant the other day and i need to bleed my system. where are the bleed screws located at?

 

Courtesy of Shoebox:

http://shbox.com/1/4th_gen_tech2.html#radflush

 

i read the write up about filling the radiator and it says to open the bleeder valves but it doesn't really describe what they look like and where they are located at. I know theres a small valve close to the radiator neck that seems like a valve. its not a screw it just has a little black cap on it. well thats one valve maybe but i still dont know where the other ones are.

 

image from shoebox's site

 

When you read the part that said "Open bleeder screws 2 or 3 turns (protect the optispark from coolant)" did you notice that the words "bleeder screws" were underlined and a different color? That's because is it a link to the same photo that brucer posted.

 

oh i didn't realize that was a hyperlink thanks a lot.