sheachopper

Have a 1988 trans am GTA 305 tpi. I can't figure out why It keeps overheating.. New radiator, thermostat, coolant temp switch, upper and lower radiator hose, radiator cap, flushed system, replaced head gasket and check block for cracks and it still over heats... I pulled the water pump off and it still spins and nothings broken... I even wired the fans to stay on all the time and it STILL overheats. I bled the system too... Either my digital guage is faulty or there's something really wrong with my trans am. I forgot to mention that the car sat for 10 years with water still in the cooling system. Anyone have any ideas of why I'm still overheating?

sofakingdom

iTrader: (1)

Define "overheating".

Describe when it does it, or not, or when it does it the worst: idling, city traffic, AC on, highway, etc.

AmpleUnicorn88

I have an 88 TBI camaro.

Which gauge do you have? I have the intellitronix one. I too have high readings on mine, and at times, it pegs out at 255. Only once was I actually overheating and that was when my water pump failed and I immediately stopped my car when it happened.

One thing I have noticed with mine is the temps rise when you do things such as turn the blower speed up, turn the headlights on, use turn signal...I believe the issue to either be a bad ground or the gauge cluster itself is bad. The oil pressure gauge has never fully displayed so I know that part is bad. So I bought one of those temperature guns from Harbor Freight to check it to see if I was overheating or not. I very rarely get a reading above 200°. I have replaced most of the same stuff you have as well minus the head gaskets and the switch. I would highly recommend investing in one of those guns. Mine was on sale for $35 normally $55. I take the temps from the back of my thermostat housing but I have tried reading around it too such as on the bolts for the T-stat housing, the intake manifold itself and the coolant temperature switch and none of them come close to high ever. I know it works because my buddy who has the same motor in his 91 is actually having overheating problems and his temps being read in the same spot read about 30-40° higher than mine. The radiator boiling over is generally a good sign that you are overheating. You could have a leak somewhere also. There's lots of things that could cause an overheating problem and the only symptom readily being shown is the gauge reading. So I would get one of those temp guns and check to see what your temps really are. If they are within 10° of what your gauge reads then your gauge is probably right and you are running hot. If your temps read low on the gun, I would say test the gun on something else you know the temperature of to confirm if you are worried. I personally trust my temp gun but they do occasionally have problems out of the box or shortly after. I don't leave it in the car so it isn't sitting in extreme heat here in Phoenix.

I am not knowledgeable at all in the tuning aspect so if it's something involving your afr, I wouldn't know how to help but plenty of people on here do.

Edit: if you don't know what gauge cluster you have check my pictures and see mine. It's the blue digital one. That's what the intellitronix one looks like. As far as I know, I think them and maybe Dakota are the only ones that make aftermarket digital gauge clusters for 3rd gens, but I'm sure one could be custom made. Don't hold me to this but I haven't seen any other ones.

rusty vango

when all else fails . have you replaced the injectors ? sometimes ,through in sufficient flow . you get a lean condition that makes a TPI car overheat. check the plugs. ohm the injectors both cold and hot. check your fuel pressure AND volume

1988CamaroSC

iTrader: (2)

hmm stupid question, but is your air dam under the car intact?

Dustin Dorr

I would check the thermostat

Iroc z_chris

sofakingdom

iTrader: (1)

Everybody comes in here and posts "my car is overheating". Gotta be the single most common post on this particular page of this forum. About 99% of the time their car is NOT "overheating", but rather is running at THE EXACT RIGHT temp but they have a bad rad cap so that it's spewing and carrying on, or they "think" that the car should run at some temp other than what the cooling system was designed to keep it at, etc.

The OP didn't tell us what the ACTUAL running temp of the engine was, what the car was ACTUALLY doing, or anything else that would help to diagnose his problem, besides spouting off the n00b BUZZWORD. Furthermore he hasn't come back in 2 solid years to tell us more, so at this point whatever problem he used to think he had back then, is not worth worrying about anymore. Might not even still have the car.

Shazam8795

Hello we are new to the site. I know this thread is dated but it did help me out and wanted to say thanks.

My son and I are working on his 1984 Trans Am 305 HO and I wanted to provide it's details for the group. Think Bandit 3. (Stupid movie but cool car.) ( We are looking for a big marlin to put on the roof . )

The Coolant temperature sending unit is exactly exactly where others have mentioned and does indeed go to the gauge. It's located in the head between Cylinder 1 and 3. And is on a different harness than the ECM.

The coolant temp sensor that feeds the ECM is located in thermostat housing in the water neck. It's a carbureted 305.

I also have another temperature sending unit on the back of the driver side head that operates the fresh air cowl induction hood.

Now I need to work on my profile. . . Later!

Thirdgen1992

TRY getting dual fans just go to the junk yard and take them from the fourth gen Camaro I’m running my 92 with dual fan with no thermostat with 2 core radiator it stay really cool with that set up !!! And it’s really hot we’re im from if your doing the fans by a switch make sure the switch has a lot of amp I have a 30 amp switch I personally do not like thermostats because they can seize up a lot I got a heavy feet lol so my car would always begin to over heat but I personal suggest to try the dual fans with the switch always have them running and take out the thermostat

cjack8

that not a stupid question because if the air dam is torn off it will cause the car to overheat because the design of the air flow

NCC-2569

iTrader: (1)

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(wrong thread)