Overheating Issue After Rebuild

Justin111

Member
Nov 28, 2011
31
0
7
Hi,

I have a 88 gt on a fresh rebuild.

Just basic bolt ons:

gt40 heads freshened up. I had them magnafluxed for cracks
explorer intake
b303 cam
new pistons, new stock crank, rods and main bearings, high volume oil pump
new thermostat replaced it twice from 192 to a 180
new water pump
65 mm throttle body
75mm mass air
155lph fuel pump
24lbs injectors
electric fan not sure what brand it looks like black magic 175
stock radiator
full exhaust no cats

after the rebuild the car is heating up. getting up to 230 after a mile down the road. I replaced the thermostat twice, flushed radiator, block was flushed when rebuilt. I don't think the electric fan is keeping up. I think I don't have a radical combo that would require a upgraded radiator. Its a GT model and I do have the air deflector installed and has a cobra grille insert to let a little more air thru. I don't have any air pockets. The fan comes on like it should. Heats up just sitting and going down the road.

I'm think of going to police fan clutch setup to ditch the electric fan.

any help?

Thanks,

Justin
 
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Lift the front end of the car and start the engine with the radiator cap off. Let it run until the thermostat opens. It truly sounds like you have air trapped. Also are ou using the stock temp gauge or an aftermarket? your sensor could be on the fritz. I would do another purge and check your sending unit before jumping into a new fan.
 
Lift the front end of the car and start the engine with the radiator cap off. Let it run until the thermostat opens. It truly sounds like you have air trapped. Also are ou using the stock temp gauge or an aftermarket? your sensor could be on the fritz. I would do another purge and check your sending unit before jumping into a new fan.


I have a aftermarket gauge. I will try that tonight. This issue was not present at all before the rebuild. its stayed at 192 all the time or even when the p.o. had a 160 stat in it it stayed at 160 degrees but he did have the fan on all the time.

Justin
 
Lift the front end of the car and start the engine with the radiator cap off. Let it run until the thermostat opens. It truly sounds like you have air trapped.

Agree. However, as soon as you start the engine with the radiator cap off, the coolant level will drop so you'll need to top it up slowly until the bubbles cease. Then put the cap back on and make sure that the overflow reservoir is topped up.
 
I jacked up the car and everything. I did get a small pocket out. I took it out last night and it got up to 210 on a cool night around 70 degrees.

I have a flex a lite fan controller on the car went the temperature probe. does that controller have the fan come at 100 percent. I thought I seen something that it only comes on at 60 percent and if you want it to turn faster you install a on/off switch.
 
Who did the rebuild? The head gaskets have to go on a certain way or the coolant passages will be blocked, causing an overheating issue.

Joe
 
Is it possible that the water pump is spinning in the wrong direction? It's worth a few minutes to check the belt routing and are you sure you have the correct water pump? I have seen this far too often. Just had a car on the dyno a few weeks ago that did the same thing and it was just belt routing.
 
I do agree with elarm it took 5 tries until i finally got my air bubble out. I had to idle the car for more than a half an hour the last time. One other thing if you are reaching temps that high you should be peein in your overflow when you shut car off if your not i would wonder about those temp numbers, i have a laser therm i got it at harbour freight for like 20 bucks very handy you can see what your temps are in any location you point it
 
Yup definitely try to make sure all the air is out. Its not the fact that the fan is electrical. I have a turbo 347 cooled by junk yard electric fans. I think the ford contour fans are the best dollar for dollar fan you can get not to mention that it flows more air then some aftermarket units. It sounds like you got all your bases covered though. I would try purging the air again.
 
Ok.... I'm a idiot... Right side head gasket on backwards. Found it the other night. I didn't run the car long cause it always overheated. Hope I didn't damage anything. There freshened up gt-40's and new pistons. At least I found it I guess.

Thanks,

Justin
 
I hope so. Thanks for the reassurance.

I'm going to be replacing the gasket saturday morning. I am going to ditch the electric fan.... didn't like it and install a heavy duty fan clutch.
 
as a precaution you should change the coolant and oil after the new head gasket. of course new gaskets.Normally a good E Fan will free up about 10hp and do a better job of cooling IMO. However that old BM fan were terrible. I would recommend getting a Taurus fan from a mid 90's car. They will pull more air than anything else and are cheap. Add a good controller and you have an excellent setup for less than $200.