blgray100

alright i have a 88 firebird 355 tpi it dident used to get hot but i blew my headgaskets and i tor down the motor put new head gaskets on it took the heads and had them surfaced and valve guides replased i replased all the cooling lines,water pump,radiator,electric fans,vally gaskets, i had the block cooling system flushed and i put headers on it because the stock manifolds i found out were bent and now if it is idling or just cruzing around town it never gets over 190 degrees but as soon as i get up to 55mph or higher is steadaly gets hoter until it starts missfiring and boiling out the overflow i hoocked my snapon scan tool to it and it sais my mass air flow censor and o2 censor is bad but that all a have also put two diferent t-stats in it no change any ideas???

quickchicken

first thing im going to ask, do you have the air dam under the front end? its that plastic thing that hangs down under the rad.

blgray100

umm no i dont never had one sence i got this car

quickchicken

get one, that is a big part of your cooling issue. our cars are bottom feeders and that airdam directs air to the rad.

blgray100

well i put a airdam on my car and even took the whole front bumper off and it still got very hot so i gave up on that car i swaped the motor and tranny over into a 88 camaro with a stock airdam and go figure it is still geting hot so hot that it blew my headgaskets i changed the gaskets again took the block and heads down to get checked for cracks or to see if they are worped but the look like new is what he said i put it together i bought a 3 chamber radiator put another electric fan on it and a 160 degree thermostat in it and still it runs between 230-250 degree what the hell is wrong????????

Red89GTA

when you put the engine back together, did you replace the water pump, or at least make sure that the pump vanes were in good shape? if it isn't circulating the coolant around, it will over heat. or you have a restriction somewhere.

antoine

How is the radiator cap

blgray100

yes i changed the water pump i have put two new ones on it and while i had it apart i used a air gun to make shure all the ports were open and they were cleer it has a new radiator and new cap and i bought radiator lines that have the springs in them to keep it from colapsing the lines i checked all the timing also thinking that it might be off a little causing it to over heat but i couldent get it any closer. i did fix my oil pressure gauge the other day and noticed when i fist start it and when im driving it is pulling 50-60 psi but when im stoped and idling its only pulling 10 could that be the problem????

blgray100

i bought this engine thrue orielys about 6 months ago brand new i realy dont recomend these motors also its kinda off topic but my car also has a power isue when its it park and im reving it it reves just like my 95 corvette has all the power in the world shakes the car just sounds mean but when i get to driving it it just falles on its face from 50mph and up under that tho i cant keep the tires planted is that just a tpi thing of another problem

redneckgames

When you checked the timing, did you confirm that the marks on the balancer are right? Meaning when the #1 piston is TDC, does the timing marks match?

blgray100

i finaly got it to stop over heating i took the thermostat out instaled a seconed radiator and 4 electric fans and extended the air dam down lower and finaly it stayes at around 220-230 thats good enuf for me lol

tchome1956

I had a heck of a time with overheating. Replaced everything. Put in a 3 core alum radiator and aftermarket electric fans with a shroud. 2 different water pumps, 3 thermostats, multiple fan switches, hoses,water wetter, etc. the hint that made the biggest impact was upgrading the fans to a set out of a 1998 z28. It immediately cooled down. I could even get on the highway at a steady. 3200 rpm in 100 plus degree weather and he temp was still ok.

kd5icr

220-230? I am sorry but that is not good enough. There are people out here running 400-600hp and they never get over 200. I will ask you, what stat do you have in it? 160,180 what temp? I had a problem over heating and as it turned out I had put in a low temp stat (160) and it ran hot all the time,why? because the coolant was not in the rad long enough to cool down with the fan as well as moving. well I put in a 180 stat and not it will not get over 190. you really dont need 4 fans I use 1 fan a 16 inch 10 blade and it does the trick. I also use water wetter just as a additive its only 10 bucks.

Marc 85Z28

The 88 and later cars have a serpentine belt setup that requires a reverse rotation water pump. A standard rotation pump will bolt right up without any indication that it's not right, other than the eventual overheating ARE YOU CERTAIN that you have a reverse rotation pump on it?