overheating problem

I own a 1988 Camaro with a 2.8 v6 MPFI engine. I just finished putting a rebuilt engine in it. the new one was built to factory specs. The only problem is that it is overheating. I can't let it idle for more that ten minutes with out the temp rising to over 250 degrees. You can here the water boiling in the radiator. so, I replaced everything in the cooling system. The fan is electric and it normally comes on at 220 degrees. It still works. I don't know what else to do. I even took the thermostat out just to make sure water was circulating. Still runs hot. Any suggestions?????

Fan working? and the sending unit?

hmm... the fan works, but it still overheats. all parts have already been replaced. thats a tough one.how much coolant did you put in when you refilled the cooling system?? shuld have been like 6-8 jugs worth of the 50/50 mix for a completely dry engine and radiator.

were all sensors transferred from the old engine to the new engine??? all leads hooked up?

you might have a damaged or failed thermostat (i kinda want to lean towards this one) i suggest pulling it out and putting it in a pan of water on the stove, with a thermometer in with it and see what temperature it opens at. its a way to test it without buying a new one.

Dont overlook the radiator cap, no pressure = lowered boiling point.

good call

true...

Could be gremlins.

all sensors were transferred from the old engine and all wires are hooked up. I also took the thermostat out to make sure that wasn't the problem. still overheats......

didnt check for the gremlins though did ya?

all sensors were transferred from the old engine and all wires are hooked up. I also took the thermostat out to make sure that wasn't the problem. still overheats......

what about hte radior cap, did you check that?

The thermostat sounds like the problem, that and radiator cap because that's what happend to me, after all that time it expanded alot.

when you say you replaced everything, did you also put in a new radiator? im assuming you did but im just banging my head on this one....


what about the plastic trim peices?? there is a cowl that fits over the fan for cooling pourposes, which would make a big difference if left off.

also there is a plastic air damn that bolts to the bottom of the radiator support and extends down about 5 inches, this is to keep hot air from circulating back around from the engine bay to the front of the radiator when sitting still. if that was gone it would create an overheating situation.