Overheating Root Cause

TBirdDriver

Registered User
There have been numerous posts here in regards to our Birds overheating. However, most of the solutions point to treating the syptoms of overheating. Has anyone had experience in diagnosing what the root cause is.
I have driven my '89 for over 10 years without an overheating problem, (my '90 however, runs hotter than it should). It seems logical to assume that the original design of the cooling setup should be sufficient to provide adequate cooling for our vehicles without resorting to lower thermostats, fan modifications, or three row rads.
What I'm getting at is this:
Has anyone ever replaced their EEC IV computer, (which controls timing), and discovered that their overheating problem disappeared? Or something else like their EGR valve or exhaust, (cats), and cured their overheating problem?
This is a recurring problem on this board. What causes our cars to suddenly start to generate more heat than normal?
(Assume that this is with a mechanically sound car, no head gasket problems, no coolant leaks, functioning thermostat, fan operates as designed, good waterpump, ect.)
 
Hmm.. While many are trying to solve overheating problems, I also think that many are just trying to reduce operating temperatures.

Yeah, a stock SC with stock exhaust, stock intake and a stuck pulley diamter might do just fine with the stock cooling system.

But if you have bumped up the power output of the engine by 22% you might expect an issue with cooling.

The stock cooling system was marginal. Remember, Ford did have head gasket trouble with these engines. Experience with this engine and the 2.9 V6 showed that much of the problem was trapped heat. Keep the engine cool (but not too cool), and it not only helps performance but helps to protect the engine.

With a 22% increase in power the stock cooling system can't cut it.
 
Both my '89 and '90 are stock with no mods.
The '89 runs cool, the '90 runs hotter.
As an experiment, can I switch the EEC IV computer from my
'89 to my '90 and see if that has any effect on the timing and
perhaps allow my '90 to run cooler?
 
i have always thinked that the engine bay of our cars ir too small and keeps to much heat inside and while i was looking at some GNX pics i had the idea of have louvers like the GNX that leave the heat get out of the engine bay
 
Saw a GN that had taken the GNX louvers and put them in the hood, on the outer sides and towards that back. Looked really good, and worked better that way. Really wouldn't look too bad on an SC hood either. Kind of TA style, I think some of them in the late 80's/early 90's had them like that.
It really is cramped in there though, and not much flow through from the front.
 
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My 90 XR-7 has 275,000km on it and runs very cool no matter what. Especially if you have the A/C running to keep the electric fan on. Only once did this motor get hot, and that was at 220,000 km from a failed head gasket.

My friend had a 93 S/C, that he bought with under 20,000km, and it ran HOT HOT HOT. The faster he drove, the hotter it got. It spit bubbles out the overflow bottle. It went in for head gaskets, twice, under warranty...not fixed.
The tranny melted down from the excess heat being transferred from the coolant and had to be rebuilt under warranty.
The rad over time blew because of excess pressure. Another warranty item.
The bottom end started knocking becuase it ran hot all the time. Complete rebuild from dealer, no long or short blocks were available at the time. It still ran hot!
Dye tested coolant....negative.
It went from dealer to dealer. One dealer claims to have fixed it... they claimed a head gasket dowel was not installed in the correct loaction from the factory.
Complete rebuild....it still ran hot.
Washed car up nice, took to dealership with A/C on so elec fan would keep car from spitting coolant onto the pavement, then drove away with a brand new mustang GT Conv.
Nothing had ever fixed the problem with this totally stock car, yet my 90 runs on the cold end of NORM all the time! Go figure!
 
WEIRD

Its weird, i really dont understand why any of these cars should overheat. I read that the SC engine needed to be stronger for the power increase so they put in more metal around the cylindar heads which made the passageway for coolant smaller so less got through, those turds!! I dont know how much of a difference this made but im sure it made the car run a little hotter,, even so, they still should have compensated for that and made the car to run easily w/o overheating. My temp gauge moves around all the time---- goes up the the edge of the "M" then the fan comes on and it cools off a little and i start driving more and it cools to the middle of "NORM" then when i stop it crawls back up--- Ive NEVER seen another car's temp gauge move around as much as the SC. Even in 100 degree weather, the other cars temp gauge never really moves at all, but mine is like the second hand on a clock sometimes-- so visible in the moving. It sucks the car has to run so hot sometimes but it has never really "over"heated and i hope it never does. If anyone has any simple solution... please share.
Damon 95 SC www.cardomain.com/id/frozenrope
 
My stock 90 started doing the same thing after 12 years of no problems. Everything was either checked out completely like radiator flow, fan switchs, fan motor, etc, etc. Many parts and sensors replaced by the dealer (at no charge) in an attempt to fix.

Nothing changed to gauge from climbing to the L in normal, even though the engine was not actually running too hot. The dealer contacted FORD and finally, a little know TSB was discovered that said if the temp sending unit is replaced, then the gauge also has to be replaced. Apparantly, the temp sending unit and the specific gauge must be calibrated as a pair or the gauge will give false readings.

There was a kit for this. The dealer finally found one of the few left and installed this kit. That fixed the problem! The kit is not listed anymore on FORD'S computer inventory system, it takes an offline search to see if any more exist.

Since it took the dealer 4 weeks to to resolve the issue, the service mananger refused to charge me. With all the dealer bashing, most deserved, I thought this was extrodinary.
 
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