Engine Over Heat At Idle
 

My Pony has 2.3L, is a 4 banger, 1988 LX Mustang Conv't. Got it from a neighbor who cheated me badly (the odometer was set back 100K, actually 157K). After some major repairs, I managed to restore the car for fun drives in summer.

It is a fuel efficient car (21 - 25 mpg) , compared to its bigger-engined brother 5.0L. However, I find it bothering recently that if I let the engine idle running, the temperature gauge would rise and rise and eventually kick in the cooling fan. Even in cold Chicago winter weather here; unbelieveable!

I have so far, replaced the fan relay module, which was burnt out outside the Cominski Park last summer due to overheated wiring, flushed the coolant, replaced the water pump, and the thermostat. But the symptom seemed to reduce just a bit. Is it true that this 2.3L engine was designed to get hot at Idle? The cooling fan kicks in often in summer time if I don't use the air conditioning, or the heater when I got caught in still traffic.

This pony runs fine when it is moving, just that it doesn't like to sit in traffic, I can't figure out why.... One thing I suspect though, I have done some body work (3) years ago, and may have painted the radiator fins in the front, I wonder if I straight out the fins and remove the painted stains, could I get a better result?

If anyone have ever had experience like this, I would like to learn a few tricks to correct this problem.

Many thanks in advance!

DOBOY1988

If you are losing water it could be a blow head gasket. If he lied to you about the odometer then you can get him for that. I do not think 25 mpg for that car is good. people for v8s get that.

Its the radiator. Get a new one. If its the original with that many miles, its probably clogged. 25mpg is about right for a convertable that is 15 years old with that many miles.

I had a similar problem but my mustang had a new radiator put in about 3 years ago and everything seems normal but from time to time it overheats. :confused: Dont know why

Re: Engine Over Heat At Idle
 

Add That Years 5.0 Liter Radiator It is thicker not wider and Holds More coolent. If you are Lucky and have Electric Cooling Fans Great :D Get the Dual fan Kit for the 5.0 allot of your heating problems will be solved. Used 5.0 Radiator copper $40 Twin Fans $75+ Depends where you buy it

Nope all Rads from 87-93 are practically the same with exception to the 93 Cobra R model which had a degas bottle on it.

Now there was an HD radiator available but. The 2.3's use the same radiator stock as a 5.0 does....

2.3L mustangs have a one core radiator, whereas the 5.0L's came with 2 core radiators. Ford Motorsport offers a 3 core radiator for Fox Body cars, which is what i bought for my stang. My '91 2.3L mustang i had, had a tiny radiator and it literally has 1/2 the cooling ability of a 2 core because there's 1/2 the surface area for heat transfer. Also with painted fins, that seriously insulates heat transfer from the radiator to the air, which is probably the culprit in this case.
If you clean off or buy a new one core radiator for your car your car should be able to get rid of all that heat, a 2 or 3 core would cool off your engine alot faster as well, but it's pretty much overkill because 2.3's when working properly don't put out alot of heat. If i were you i would probably get a brand new radiator unless you're confident you can get all the chemicals off your radiator and the condition of the inside of the radiator is that it isn't rusted or anything like that. The fact that your cooling fan is constantly kicking on and even overheating the wiring shows that your car isn't able to shed enough heat from the radiator, especially if using the heater (heater core - mini radiator) helps cool it down.
Keep us posted on what you find.