ok guys i need some serious help! ok i drive a 87 firebird V6, its my everyday car. my car used to overheat until i put a new rad in. i drove it from oklahoma to missouri and it still was just fine. just a few days ago it started overheating again. so i said screw this and i replaced everything. thermostat, waterpump, rad, heater control valve, heatercore, hoses, i fushed it twice. and its still overheating. now its ok when its in idle but when i start going about 20-30 mph it overheats. the only thing i can think of is that when i had my old rad in the car my friend put some stopleak in it....but i flushed it....i dont have a clue in what to do now...plz help

 

Yeah I had the same problem I put stop leak into my car and for a while it was okay then it started overheating. I flushed it and changed everything under the sun. The only way I was able to solve the problem believe it or not was with a complete teardown kinda sucks, to try and solve a problem with a simple solution then only have a bigger one snow ball on you.

 

dang well i hope it doesnt come down to that...i dont think my timing is off but ill double check to make sure

 

Yeah I found that leak stop crap plugging up the pores to the heads. I don't recommend that crap. The best thing to do is simply fix the problem you'll thank yourself in the end.

 

well will fushing it a couple of times help?

 

Is there an air dam underneath car? It should overheat worse at idle if it were a clogging issue shouldn't it? If it overheats while driving, sounds like the air dam is missing or something (assuming there is an air dam on the Firebirds - the Camaro's have 'em).

 

Yeah I would go with IrocGta's conclusion because that stuff does have a tendency to block up the internal passages of the motor it happened to my 70 El Camino and my 97 Chevy Venture same problem of over heating once I used that stuff. You'll need a complete tear down and rebuild to get the car working correctly again. She probably won't be too bad in the winter so long as you are moving but forget about criusing around during summer months.