I have a 90 Ford Mustang with a carbed 306 with a T5.
I got completely swindled on buying it, it repeatedly overheated on the way home and I may be stuck with it.
Anyway, the problem is that the car overheats after a few minutes of driving. It does not overheat at idle, at least it does not overheat as rapidly as when it is driving.
There are no leaks, the coolant reservoir and large aluminum radiator are full, no hoses appear to be collapsing and the fan spins like it is supposed to.
I removed the thermostat and it cooled down significantly, but it still began to overheat after about 15-20 minutes of driving. This was not bumper to bumper traffic either.
Since it is bored out a little and Memphis is kinda hot this time of year I would expect it to run a little warm. Did you call the guy you bought it from? He may not have tried to swindle you, he may have just changed fluids and left an air bubble in the radiator. I would give him a chance to make it right. If that is not an option: Make sure you don't have oil and coolant mixing, flush your system, replace your thermostat with a 180 (I would reccomend), add some water wetter by redline, check your radiator for debris (critters, plastic bags, leaves etc) you may need to go electric fans and build a shroud if you don't have one.
Since it is bored out a little and Memphis is kinda hot this time of year I would expect it to run a little warm. Did you call the guy you bought it from? He may not have tried to swindle you, he may have just changed fluids and left an air bubble in the radiator. I would give him a chance to make it right. If that is not an option: Make sure you don't have oil and coolant mixing, flush your system, replace your thermostat with a 180 (I would reccomend), add some water wetter by redline, check your radiator for debris (critters, plastic bags, leaves etc) you may need to go electric fans and build a shroud if you don't have one.
This is a major overheating problem. There is no air in the system. They also lied about other things and refused to refund my money even if I had it towed at my expensive. It took me at least 3 and a half overs to drive it 35 miles home after I bought it.
Sorry you got burned. I'm surprised these things didn't show up when you test drove it. I always put 30 minutes or so behind the wheel when I test drive one. Did any of the obvious things I mentioned appear to be on?
If it looks like the original radiator, you may (probably do) need a new radiator.
Depending on the setup on the motor (how many horses will it run), size of carburetor, state of tune, etc, you may need more radiator than a stock item designed for a 215 hp fuel injected motor anyway.
Are any of the radiator hoses being sucked flat when the car runs or starts to overheat?
Have you checked the oil for water - and the water for oil? Like snake says, its best to know...
Finally, you may just be looking at a bad build. Does the motor (or gaskets) look new? Its possible whoever built it blocked a coolant passage during the build - in which case only a disassembly will get you fixed.
Now that I'm thinking about that, are you leaking from the head gaskets - is there any white smoke coming from the tailpipes?
I'd do those checks we mentioned, then pull that radiator and have it checked at a radiator shop.
If it just needs a cleaning (or even a new radiator) count yourself lucky.
Snake is right, 180 degree thermostat and water wetter ( I use both myself ). But I suspect you're going to need more.
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tripleblack
"You can never be free until you let yourself go."
ive had electric fans on my car since i bought it, but does the stock fan have a clutch? if so it could be that.
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White 89 hatchback. 4cyl auto to 5.0 manual. k&n intake. 150 amp alt. msd ingition and distributor. accel super stock wires. yellow-top bat. raizin voltage stabilizer kit. MAC shorty equal lengths. off road H with flows. king cobra clutch. hurst shifter. 3.55's. lowered. mach 1 hood.
Hopefully its a minor issue.. Cooling systems are pretty basic. Sounds like a stuck t-stat. Easy to test, start the car-let it run, keep feeling the upper and lower radiator hoses. Until the stat opens, one will be hot and one will be cool. If it starts to overheat and one hose is still cool thats your issue. My opinion- If your planning on adding power to the motor. Get an alum rad, 160 or 180 t-stat, hi flow water pump and an elec fan plus some water wetter. You can run wide open in the desert and not overheat.. Good luck
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90 GT Vert- Flowmasters, BBK Cold , 9MM FR Wires MSD 6A Ignition, MSD Blaster, B+M shifter..3.73's in Rear. BBK Equal Length Shorty Headers. BBK off road X pipe.70mm TB, Alum FW. Alum DS. Upgraded Rebuilt T-5 w/295first. 93 cobra wheels w/nits. Elec Fan. AP pulley. Ford Racing Mini Starter. Energy Suspension Motor/Trans mounts. Trick Flow Intake, 30lb injectors and MAF, Steeda Alum Control Arms,Steeda Sway Bars, Steeda Sport Springs, Complete rear disc from 93 Cobra,
Sounds like the rad to me. If it's old and crappy, it's probably toast. If the bottom of the rad is cool when the upper portion is hot, that's a good sign that you need a new one.
It also may have the incorrect waterpump. The serpentine belt uses a reverse-rotation waterpump, if you put an older pump on, it will spin backward, and not work well.
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1992 Deep Emerald Green Mustang GT Hatch, 5 speed, 2.73s, Mac fenderwell cold air intake, '93 Cobra MAF, Mac 70mm throttle body & spacer, Explorer intakes, Mac unequal headers & offroad pipe, Magnaflow catback, Walbro 110lph fuel pump, Jet adjustable FPR, MSD Blaster coil, Accel 8mm wires, FRPP aluminum quadrant, UPR firewall adjuster, stock cable, Granatelli upper control arms.
Waiting to go on: Granatelli lower control arms, and GT40 Iron heads!
Sounds like the rad to me. If it's old and crappy, it's probably toast. If the bottom of the rad is cool when the upper portion is hot, that's a good sign that you need a new one.
It also may have the incorrect waterpump. The serpentine belt uses a reverse-rotation waterpump, if you put an older pump on, it will spin backward, and not work well.
Overheating problem 
