1987 Firebird Formula Thermostat Housing
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Car: 1987 Firebird Formula
Engine: 305 5.0L Carbeurated V8
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1987 Firebird Formula Thermostat Housing
Alright so Iv'e run into a bit of a setback. I bought a 1987 Firebird Formula a few weeks ago for about 1000. Obviously the car is not in mint condition but it does run and I thought I could fix it up pretty good myself. Anyways the first thing I noticed wrong was that the previous owner had disconnected the AC system so that they could turn on the AC switch inside the car causing the fan to come on without actually having any cold air blow into the car. Don't ask me why. I think this woman just knew her car was overheating because the fan wasn't come on automatically like its supposed too once the engine reaches a certain temperature, and this is how she decided to fix it.
So after rerigging the AC and discovering the reason for the MacGyver fan hotwire in the firstplace now I needed to fix the overheating problem myself. Off the top of my head I decided to test the radiator cap and replace the thermostat. The radiator cap was fine but when I tried to remove the bolts holding the thermostat housing in place they wouldn't budge. So I got a bigger ratchet and tried again. Still these bolts wouldn't move. Finally I got out my breaker bar and tried to remove the first bolt. Not surprisingly the head broke off the bolt. So I moved to the second bolt and the same thing happened. Now here I am with two headless thermostat housing cover bolts.
That sucks but I thought I'd at least be able to lift the housing off now since the heads arent there anymore. But even without the bolts its still stuck fast and I have no idea why. The only thing I can think of is that the holes in the thermostat housing are threaded? Which would normally be hard for me to believe considering I've never seen a threaded thermostat housing. Usually only the exhaust manifold has threaded holes and the bolts go through smooth holes in the housing cover and screw into the threaded holes in the manifold, holding it in place. (sorry, I'm trying to explain this the best I can)
So basically I have two questions.
1. Anyone who has any real experiece with the 87 Formula, are the holes in the thermostat housing threaded?
2. And how the **** do I get those broken bolts out?
So after rerigging the AC and discovering the reason for the MacGyver fan hotwire in the firstplace now I needed to fix the overheating problem myself. Off the top of my head I decided to test the radiator cap and replace the thermostat. The radiator cap was fine but when I tried to remove the bolts holding the thermostat housing in place they wouldn't budge. So I got a bigger ratchet and tried again. Still these bolts wouldn't move. Finally I got out my breaker bar and tried to remove the first bolt. Not surprisingly the head broke off the bolt. So I moved to the second bolt and the same thing happened. Now here I am with two headless thermostat housing cover bolts.
That sucks but I thought I'd at least be able to lift the housing off now since the heads arent there anymore. But even without the bolts its still stuck fast and I have no idea why. The only thing I can think of is that the holes in the thermostat housing are threaded? Which would normally be hard for me to believe considering I've never seen a threaded thermostat housing. Usually only the exhaust manifold has threaded holes and the bolts go through smooth holes in the housing cover and screw into the threaded holes in the manifold, holding it in place. (sorry, I'm trying to explain this the best I can)
So basically I have two questions.
1. Anyone who has any real experiece with the 87 Formula, are the holes in the thermostat housing threaded?
2. And how the **** do I get those broken bolts out?
Last edited by thomashearts; 02-07-2016 at 06:25 PM.
#2
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Re: 1987 Firebird Formula Thermostat Housing
the first thing I noticed wrong was that the previous owner had disconnected the AC system so that they could turn on the AC switch inside the car causing the fan to come on without actually having any cold air blow into the car.
Anyone who has any real experiece with the 87 Formula, are the holes in the thermostat housing threaded?
And how the **** do I get those broken bolts out?
Good luck !
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Car: 1987 Firebird Formula
Engine: 305 5.0L Carbeurated V8
Transmission: Automatic
Re: 1987 Firebird Formula Thermostat Housing
This is exactly what is supposed to happen; The Engine fan is activated when the HVAC control is moved to any AC position to reduce engine temps that are higher then when the AC is not operating.
No - they are not threaded.
Drill a hole thru the center of each busted bolt ( don't drill THRU the intake !! ) and use an EZ-out. this is the best type of bolt removal tool I've ever used.
Good luck !
No - they are not threaded.
Drill a hole thru the center of each busted bolt ( don't drill THRU the intake !! ) and use an EZ-out. this is the best type of bolt removal tool I've ever used.
Good luck !
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Car: 88GTA
Engine: 5.7TPI
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Re: 1987 Firebird Formula Thermostat Housing
I used these for the exact same problem; head broke right off. Went to Advance and picked up these, sprayed some PB Blaster on it. Then put this on it. While applying constant steady force, I tapped on the top of the breaker bar. the stud came right out. Then chase the threads if need be. And no drilling required. Good luck
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Car: 1987 Firebird Formula
Engine: 305 5.0L Carbeurated V8
Transmission: Automatic
Re: 1987 Firebird Formula Thermostat Housing
I used these for the exact same problem; head broke right off. Went to Advance and picked up these, sprayed some PB Blaster on it. Then put this on it. While applying constant steady force, I tapped on the top of the breaker bar. the stud came right out. Then chase the threads if need be. And no drilling required. Good luck
BikeMaster Drive Heavy-Duty Stud Extractor
Last edited by thomashearts; 03-28-2016 at 02:36 PM.
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Car: 1988 GTA
Engine: VIN F 305 TPI
Transmission: AUto
Re: 1987 Firebird Formula Thermostat Housing
Since you did not mention a second fan, I assume you have an E vin engine.
Here is the fan diagram for that engine. The Coolant fan switch is in parallel with the AC control so either 238°F or AC on should turn the fan on. Since the fan turns on with the AC switch, the relay must work so change the Coolant fan switch.
Here is the fan diagram for that engine. The Coolant fan switch is in parallel with the AC control so either 238°F or AC on should turn the fan on. Since the fan turns on with the AC switch, the relay must work so change the Coolant fan switch.
#7
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Car: 1987 Firebird Formula
Engine: 305 5.0L Carbeurated V8
Transmission: Automatic
Re: 1987 Firebird Formula Thermostat Housing
Since you did not mention a second fan, I assume you have an E vin engine.
Here is the fan diagram for that engine. The Coolant fan switch is in parallel with the AC control so either 238°F or AC on should turn the fan on. Since the fan turns on with the AC switch, the relay must work so change the Coolant fan switch.
Here is the fan diagram for that engine. The Coolant fan switch is in parallel with the AC control so either 238°F or AC on should turn the fan on. Since the fan turns on with the AC switch, the relay must work so change the Coolant fan switch.
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Re: 1987 Firebird Formula Thermostat Housing
I beleave the switch is between the 6 and 8 plugs on the head.
Put the key in the "on" position and ground the wire that goes to the switch on bare mettle. The fan should go on. I believe its a black wire.
There is also a "knock" censer in that area that looks similar . It should have a dark blue wire
Put the key in the "on" position and ground the wire that goes to the switch on bare mettle. The fan should go on. I believe its a black wire.
There is also a "knock" censer in that area that looks similar . It should have a dark blue wire
Last edited by Ron U.S.M.C.; 03-31-2016 at 05:58 PM.
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