85 firebird overheating

8

85firebird

New member
Joined
Sep 4, 2015
Messages
3
Reaction score
0
Points
0
Location
Florida
Hey I have an 85 v6 firebird that runs hot and occasionally overheats to the point that the water in the plastic reservoir boils. Radiator and water pump are fairly new, no flow blockage, fan is on a toggle switch. Currently have no thermostat in the car. I've been told that not having the plastic fender type thing under the front of the car (rubbing it on steep driveways and speed bumps over the years pulled it off) can contribute to the car running hot. Going to put a new thermostat in but not sure why it runs so hot. Any tips or help would be greatly appreciated.
 
The Air Dam helps with cooling. It creates a low pressure area that pulls air through the Radiator. Make sure there is nothing blocking the airflow through the Radiator also.
 
1. Does it overheat on the highway or when driving at low speeds or both situations?
2. Are you using antifreeze/engine coolant or only water?
3. Any indication of any leaking coolant other than the reservoir?
4. Have you pressure tested the cooling system cap?
5. Any brownish creamy substance in the oil filler cap or on the dipstick?
 
85 firebird

I've looked up air dam replacements. I intend on getting one as soon as I can. the original one tore off about 6 years ago, but my overheating problems started around 4 years ago, replaced waterpump and radiator ect.

I only have water in the system lately but have been told that I shouldn't, that I could develop hard water deposits that can clog the system.

I don't believe I have a leak in the system but have never done a pressure test.

No problems with the oil.

As I said previously I have the fan on a toggle switch so when I drive for a while, or sit in traffic, I have it running and usually the car runs hot but doesn't overheat to the point of boiling water. I've only had that happen a few times.

I do not have any gages however, currently only dummy lights.

I don't drive on the highway very often so I don't know if that causes overheating.
______________________________
 
the fan that you have on a toggle switch is this the factory fan and if not if you don't have the fan shroud on the radiator than the fan cant suck air through the radiator to cool the engine. no matter what I would run that fan all the time
 
if you have a properly functioning 15lb radiator cap the boiling point of pure water is 257F degrees. With a 50/50 mix of antifreeze it raises to 265F degrees. Install a 180F thermostat and a 50/50 mix of antifreeze and replace the cap. Why are you manually controlling the fan rather than fixing the system?
 
melsg5 said:
if you have a properly functioning 15lb radiator cap the boiling point of pure water is 257F degrees. With a 50/50 mix of antifreeze it raises to 265F degrees. Install a 180F thermostat and a 50/50 mix of antifreeze and replace the cap. Why are you manually controlling the fan rather than fixing the system?
Click to expand...

Agreed. You should definitely run a 50/50 mix
______________________________
 
Still problems

Okay,

Over the weekend I took the cooling system apart and cleaned out hard water deposits, flushed radiator, and went to install a new thermostat. I had to replace one of the bolts on the housing because the old one wouldn't tighten, I managed to get the new one as tight as possible, I added distilled water and antifreeze, let the car warm up to check for leaks and make sure the water flowed, there were no problems there. When I went for a drive, I had a weird sputter when I accelerated. Seems to be running roughly and I have no idea what could cause it since I only worked on the cooling system and everything seemed to be working correctly.

My next work will be purchasing gauges (no gauges at all currently only dummy lights) so I can tell what the actual running temp is and an air dam when I can afford it.
 
Check your ground ( negative cable) Some V8's run it to the Tstat housing stud. If you dissconected it , the computor goes into "Limp Mode" for a while .

Check your computor grounds also , must be nice and clean and they are grounded to the motor. ( a group of black wires)

You put in the correct temp stat ? If too cold , the computor gives the engine more fuel.

Doug in P.R.:cool:
 
You must log in or register to reply here.

Share this page

Back
Top