I recently purchased an 88 GTA Trans Am. It has the 350 Tuned Port Injected Engine. This car has been sold time and time again because no one can get it to run cool. So here is the deal. When I first got the car, it would boil over 260 degrees plus in about 10 miles including freeway driving. After closer inspection, I found that there was no Air Dam on the car, so I quickly installed a new one in hopes of curing this problem. Well it helped a little bit and delayed overheating for another 7 or 8 miles or around 15 minutes or so. but then the car shoots right back up there. There are dual cooling fans, both are set to turn on with the ignition, and both are functioning fine. The radiator cap is a 14 PSI w/ pressure release valve. The Radiator was replaced w/ a new 3 core radiator and seems to be working fine, I have flushed it out and installed a 50/50 mix of coolant and with the cap open the radiator appears to be functioning fine. The thermostat seems to be working fine, and was replaced a couple weeks ago. the water pump is showing no wear, is not leaking or making any noise and i cant seem to justify replacing it, also i was told it was replaced by the previous owner. I cant see the lower hose collapsing allthough this may just be because its in park and not on the highway. It seems to me i have covered all the bases on this engine, so now i am asking anyone else for help. The engine does not smoke, tick, knock, or bog. it does not leak or show any weakness. The fuel pump moans and i think it will be the next to go, but thats all. Is there something wrong with the heads to overheat? any ideas as to what the hell the problem is. its been 40 degrees around here lately, how can this car get so hot so fast with everything in tact. any help would be appreciated. thanks

 

Squeeze the lower hose. See if it feels soft.
I wonder if the previous owner put the wrong water pump on. I believe the 88 had a reverse flow pump.
Are the fans sucking air from the front of the radiator and not trying to blow it to the front?

 

Allright here is the deal, I am a little dumb founded as to this cars engine, and cant get into the back of the block to get the casting numbers. the car is an 87 GTA after closer inspection, and the engine looks identical to the 89 TA 350 I have in my 86 Iroc. It is a full serp setup and the alternator is on the right hand side, when i got a belt for an 87 350 engine it was completely different, then again the install looks stock, and all smog and a/c equipment is there. I did some research on the visual aspects of 87-89 motors and cant find any info. so if indeed the 88 was reverse flow, then odds are the parts for this car would be for an 87 engine because previous owners were complete idiots. Ill go outside in a min and check the hose, also take some pics of the engine so someone can help me identify it. it has centerbolt heads, and is identical to my 89 engine inside and out. I never had an 87 tpi, only 86's and 89s... let me know
thanks

 

Check the 8th digit in the vin. I believe doing that holds true even on your year. If it's an 8 you have the 350.

Where at in Wis are you?

 

The vin is an 8, but the motor does not look to be an 87. I checked the lower hose, it has the coil springs in it and appears to be nice and stiff. here is a pic of the motor, i wish i could figure out this heating issue.

thanks

 

Have you checked the belt routing? It could be on wrong. I don't know of any visual differences between the 305/350/years with tpi.
Does it overheat at idle?

 

the belt is routed right, and it doesnt boil over at idle, then again we dont sit there long enough to find out. im at a loss with this problem, i mean wtf, the fans are manual. the radiators new, thermostat is new, what the hell can it be. i have never had this problem before.

 

Check the direction of flow on your fans. If they're pushing the air to the front of the car it won't overheat at idle but it will while driving.

 

which direction do they need to be facing, and how do i change it. i didnt hook the fans up on the manual assembly. so i am not to sure what was done there. is there a way to reverse the flow of the fans?

 

Ground your ALDL port like you were checking codes. This will turn on your fans.
The fans should be on the engine side of the radiator.
They should be sucking air through the radiator and blowing it towards the engine itself.
I believe all you have to do to reverse the flow is change the polarity of the wires. hook up backwards.

 

the fans arent hooked up to the ecm anymore, they turn on with the ignition, some idiots way to do things. i will however check that out and see what i can do, one thing i never really got a chance to look. im going to be installing an msd ignition and an accel wires and plug setup, so when i am doing that this afternoon, i will check that all out..

 

just like you do and did everything from gettin the big 31x19 griffin radiator and switchin themostats and hoses and water pumps and fans with no help.. it ended up bein my aftermarket pulleys. witch i replaced yesterday and problem soved yyeeeaahhh. but still not sure if itll overheat around town i havent given it a chance and hopelly wont. but it made a big difference on highway speeds so im happy i can get to work just fine. on the highway it barely goes up to 200 but starts rising quick as soon as i get into town. so im gonna try yet another waterpump (one of those hiflow ones) to hopefully solve the in town. hope it helps

 

!

 

yep, like was already said.. check that water pump.. it might be the wrong pump for your application, you defently need a reverse pump if you are running a serp setup.. take it off and actually see which way the fins face.. reverse and standard pumps look identical on the outside.. that would defently cause a major over heating problem.. another possibility could be a blockage somewhere in the block.. has the engine ever had freeze plugs replaced? the reason i ask is because i know many techs who are too lazy to drill and pull them out and will instead just smack them into the block.. when your only paid for so many hours on a job cutting corners to do the job faster seems to be the industry norm..that can cause you some fun overheating problems and damn near impossible to figure out... most people dont think of it..good luck, let us know the cause when you figure it out!

 

oh and like someone else said.. aftermarket pulleys.. underdrive pulleys are notorious for causing heating problems do to spinning the water pump too slow.

 

That has to be an 88 car, unless the previous owner switched all of the accessories to a serpentine system. 87 came with v-belts. Have you opened the water pump and visually inspected the propellar to check for wear? I'd suggest to not even bother, and order a stewart water pump for your car. It's sure to help and maybe even completely fix your problem.

 

It was the lower portion of the air dam, it was missing so just the lip was there. the car has since been fixed and sold, thanks everyone for input into fixing the car, never realized how important and air dam was. thanks