Ok I have a 86 T/A 305 TPI that I bought in November 2009 for $200 off I guy moving outta of town(Solid body all it needed was a paint job and he said that it needed a new radiator).... When I first brought it home I had a new radiator put into it and then It just sat in front of the house for a while, I would say in about February I started fooling with the car and i have been having problems with it overheating since. What the car is doing is while im driving the car the temp gauge goes up from anywhere between 220 to 260 but when I slow down or stop at like a stop light it usually drops down to a stable 220, I replaced the thermostat and the radiator like the guy said and it is still having the same problem. After I put the new thermostat in and drove it home(I was driving kinda of hard) when I parked the car, my brother said he heard water bubbling so I popped the hood and coolant in the overflow tank was bubbling, The car has been overheating since i got it but it never bubbled in the overflow tank like that before, worried that i finally screwed something up with my car I took it up to a local firestone, he said they found a air pocket in the cooling system, he got the pocket out of the car and retested the car and came up with it being the headgasket that is causing the overheating, the guy told me that the pressure was being pushed into the radiator. I didnt think it was the headgasket because im not losing coolant, there isnt coolant in my oil, and there is no steam coming from the exhaust, also when i tuned my car a couple of weeks ago there was no wet spark plugs.... So what i did next was take it to mieneke and had them take a look at it, he said that it is overheating but couldnt come up with a reason why, he also said that he talked with some mecahnics he knew and they said it might be a internal water pump issue, I asked the man at mienieke could it possibly be the headgasket and he said he didnt think so because the car was still running and performing to well, so with that said TODAY I had a new water pump put on my Trans am and it is still doing the same thing..... Does anyone know what it could possibly be, Im trying to figure out what is wrong with this car before I burn the motor up, Does it sound like it might be the head?? Has anybody on the forum had this problem??..... Also the "Service Engine Light" Keeps going on and off sporadically, And I dont think its the fan because it appears to be coming on and spinning pretty strongly..... Can some one please help!!!!!!!!!

 

Look under your car to see if the Air Dam is there or broken off/removed!!!

Its a black piece of plastic that runs across the front, under the nose of the car and is about 3in tall.......big part of cooling system.

 

do a compression test 305s are known for high mileage head problems especially since the car has been sitting for an extended period of time... and try replacing the fan clutch also

 

Hey Dan if it was a head problem, would a head gasket kit at like an auto zone have everything I need to fix it(I have a mechanic in the family and he says if I buy parts he will fix for $200)

 

y84pauloflondon, I looked under the car and i am just a little confused at what Im looking for exactly is it near the front bumper???

 

it really depends on how hot you have driven the car in the past, first you need to do a compression test, then you really should do head gaskets on it because of how long its been sitting but if its been ran hot you might have warped heads also which means they need to be machined you need to take the heads off to really know i had the same problem with my 307 stroker and it ended up being heads... bubbling in the resivior running hot i changed the thermosdat upper and lower hoses radiator fan clutch and non of that fixed it... quick question when you shut the car off after driving it for a while does it stay running for a sec. after the key is taken out?

 

If your car is OK when idling or going slow it's not an engine problem but an airflow one. Like y84pauloflondon said, check to see if you even have an air dam under the front of the car. That's the only way air gets through the radiator at speed. It a little unique to car that have no grill opening to let air through. Do a search on this cooling thread if you need more info. Good luck

 

yes it does but just for a second

 

look for the fan... when u see the fan there is a little disc attached to it. that little disc in the fan clutch

 

ok.. well the timing is out then try advancing it or retatarding itand do head gaskets itll benifit you

 

so you think it might be the fan, and what about the disk am i looking for

 

its attached to the fan go on google and type in fan clutch under images and itll show you what and were it is

 

Like Paul suggested, check to be sure the air dam is in place. The symptoms you've described are what happens when there's no air dam under the radiator. Shapes and sizes vary with model years, so here are a few examples to look at, just in case you're not sure what we're talking about.

This piece mounts the the bottom of the radiator support frame:
http://www.hawksthirdgenparts.com/de...deflector.aspx

And these are various types of air dams that mount to the above piece:
http://www.hawksthirdgenparts.com/fi...deflector.aspx
http://www.hawksthirdgenparts.com/fi...tscooling.aspx

Since there's no direct airflow into the radiator of a Firebird, the air dam is vital to directing air up to the radiator when the car is moving. Without it, the radiator won't get sufficient air to provide for any cooling.

As for a 305 being "known" for developing head problems, I've put A LOT of miles on several 305s, and I've never had any problems with the heads or head gaskets, nor have I ever even heard of such a thing. I'm not saying you couldn't have a blown head gasket, though it doesn't sound like you do, but if you do, I wouldn't consider it common, by any means.

 

In the Cooling forum, down 7 post from yours, is one from 87muscleman showing the airdam. you should make sure you have one before spending any more time or money! Please do this

 

OOPS, sorry about the repetition, I guess I'm just slow at typing. What LAfireboyd said!!

 

Your car should have an electric fan, so there is no fan clutch to look for.

 

So this air dam shoud be directly under the radiator Correct??

 

Yes. It's black plastic, and it runs along the lower radiator support frame, and it hangs down lower than the car's gfx, so it can "scoop" air up to the radiator as air passes underneath the front of the car. Different car models have different shape air dams, but all thirdgens use one of some shape or another... some one-piece and some three-piece.

 

Its 305 TPI engine, it should have the 2 electric fans NOT a clutch fan! If your car can hold temp at idle on the driveway, your gaskets are fine and so is the engine. If its overheating while driving(like you said it was), and since you are confused about what a Air Dam is even after looking under your car, then I would bet that your Air Dam is missing!!!!!

Get an Air Dam!!!!!!

 

Or maybe his tires are low on air, he should fill them up at a gas station. While he's there, he should wash his car. A clean, shiny car will have less air/wind resistance and therefore the engine will run cooler.....

JK guys!

 

Coolant bubbling/boiling? First things first you should replace your antifreeze if you haven't already done so. Make sure its a 50/50 mix and not more water because that is what bubbling in the overflow tank sounds like to me! One thing you might want to check is the Coolant fan switch located on the p/s of the engine block between plugs #6 and 8. If you have electric fans than your fan switch might be faulty or the wire became disconnected. The wire and pigtail are notorious for becoming brittle and falling out due to their close proximity to the exhaust header. Just a thought!

 

Dredre08- first things first!!! Lets start with the basics before ripping apart the engine

1. Look/check for Air Dam...If its missing or damaged, replace it.
2. Use a coolant/antifreeze tester. Make sure your coolant is good.(50/50 mix)
3. Check to see if the fans turn on.
4. If fan don't turn On, check fan fuses.
5. If the fuses are good, take 2 wires and connect to battery(1 wire for -/ 1 wire for +), then connect the wires to each fan too make sure that the fans do work when juiced. If the fans work, go to step 6.
6. Check Fan Cooling Switch, make sure connection is good.
7. If your still running HOT, and your fans are NOT turning on, replace Fan Cooling Switch.

Note: Your Air Dam should look something like this.... http://i42.photobucket.com/albums/e3...irdaero039.jpg

 

Ok I looked under my car and it appears that the air dam is in fact MISSING....... Is there a specific one for the 86 Trans Am and if so does any one know where I could get it, because after goggling it i have seen a variety of different dams

 

See problem solved!!!!!
1. Dealership
2. Hawks
3. I think.....Thirdgen Ranch sales parts!!!
4. A1 Auto....maybe there!
5. Autowreckers

Well Done! and Good Luck Hunting!

 

My 87 GTA's Air Dam is a long single piece, would think that yours would be the same since the 86 and 87 T/A bodies are so much alike. The link I posted above seems to be a 3 piece Air Dam(which year? I'm not sure).

But PLEASE double check for yourself!!!!

 

Ok..... So I ordered one from ebay, thanks guys...... Just asking... how hot could the car run without having this Air Dam????????????

 

Without one????........enough to blow a gasket and then your engine!!!!

Then you could use your engine block as a paper weight!!!!