1986 mustang gt over heating

[mustang_gt88]

the car has a 91 ho 302, flex fan, under drive crank pulley, stock water pump and alternator pulleys, no fan shroud. The car runs great but it slowly get hot(i shut the car off at 210-230). I put a 160 therm, i can see the water circulating in the radiator, new upper and lower hose. does anyone have any idea as to whats wrong? Do i need the shroud, high flow water pump, or a 3 core radiator instead of 2 core. thanks

[RACEME]

make sure you have the correct water pump. Some are designed to spin the other way. If you are running a belt-driven fan, then you probably want to put a shroud back on it too. You might also take the thermostat completely out for a test to see how that changes things.

[89redgt]

Does the car get hot when you drive it on the highway?

If it does not get hot on the highway but it does sitting in traffic i would supect you have a air flow problem which putting the fan shroud back on may fix.

[RIXXX93GT]

Put the shroud back on and also if someone took the air deflector off the bottom of the core support put that back on also. Stick with a 180 thermostat, removing the thermostat is not a good idea it wont let the water/coolant soak up the heat as its moving too fast through the block. Have you determined if the thermostat is opening at the right temp?

[mustang_gt88]

The car holds a good temp going down the road. Have driven 20 miles and al is fine. Just went it sits and runs. How can I determine if the thermostat is opening up at the right themp? Thanks for the help this is why i love this site.

[Rich]

Just like the others have said...

1. Fan shroud on(probably the issue)
2. 180 thermostat, installed correctly
3. if radiator is old, have it cleaned at a radiator shop
4. Get rid of the flex fan and run a stock one with a stock or HD fan clutch
5. air deflector on bottom of radiator support

With everything in good working order, the car should be able to sit/idle in 100*+ weather with the AC on and not have any issues.

[setty2706]

Just like the others have said...

1. Fan shroud on(probably the issue)
2. 180 thermostat, installed correctly
3. if radiator is old, have it cleaned at a radiator shop
4. Get rid of the flex fan and run a stock one with a stock or HD fan clutch
5. air deflector on bottom of radiator support

With everything in good working order, the car should be able to sit/idle in 100*+ weather with the AC on and not have any issues.

100% agree..... Its amazing what the clutch fan actually does.. I had overheating issues and put a new clutch fan on and the issue stopped..

[03z06vette]

Screw the clutch fan. Electric fan is the only way to go.... JMO. It will cost the same as getting a clutch, fan a shroud etc..

[Pitbull1052]

Screw the clutch fan. Electric fan is the only way to go.... JMO. It will cost the same as getting a clutch, fan a shroud etc..



What Tom said...... Also I had this happen once I bought a used 2 row rad, ran some water through it etc seemed fine... threw it in seemed to work well on the test run... drove it to work the next day it started to overheat. Checked it when i got home and I guess there was a ton of rust or what looked like rust in it. I had to flush my radiator like 5 times, change the thermostat and the water pump because of it......

[mustang_gt88]

thanks for the help ordered a fan shroud and clutch fan

[85_SS_302_Coupe]

No tstat or a low temp tstat is a bad idea unless you have a super badass 3+ core radiator that can cool things down in a hurry. If you're running a stock radiator, it's a definite no no. The fan shroud and deflector under the core support are pretty important parts of the cooling system. The shroud directs air through the entire core...making a sort of vacuum effect working with the fan, and the deflector creates an area of low pressure which makes it easier to draw air through the radiator. Another thing to look at is make sure your serpentine belt is routed the right way. You may have the right water pump but it's spinning the wrong direction because of your belt routing.