overheating problem

Robogast

Robogast

Mechanic
Jun 14, 2006
58
0
0
VA Beach, VA
Hello, i have an 87t and i have been having problems with it overheating. i replaced the headgasket and got the head decked and didnt have time to get the block decked because i had to deploy. but i deleted the thermostat, replaced the thermostat, and flushed the radiator and it still overheats. i am planning on getting a upgraded cooling package and a bigger intercooler kit. as of right now i have 550cc inj., 3in.exhaust, turbo elbow, walbro fuel pump, afr, and a few other things i cant remember right now. but i was wondering what might be the cause of it overheating? and what can i do to fix it? thanks, Josh
 
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Nick M

Nick M

Black Rifles Matter
Sep 9, 2005
8,897
40
48
U.S.
www.ebay.com
Assuming you don't have an engine problem, but a cooling problem, here is what you need.

The corret thermostat. A working fan clutch. A fan shroud that is complete, and not broken, and the lower engine cover. Then you need a radiator that flows well, and is not obstructed on the outside with debris. Flushing it only removes the loose crap. Sometimes they need to go in the garbage. And of course you need a working water pump, with a belt attached.
 
jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
^ I'm with stupid ;)

Highway? Traffic? Just after reducing speed? Just after shutdown? What is the temp gage behavior when it happens? Can you reduce temperature using the heater? Gurgling? Appearance of gas (tiny bubbles) or foam in the coolant? Any coolant loss from day to day? I fail to see how people expect help when they force me to play 20 questions. Ok, 9 questions...
 
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mkIIIman089

Supramania Contributor
Mar 30, 2005
3,061
0
36
Ohio
Then its normal. Except
jetjock said:
If it's puking coolant out the overflow tank it's not normal. The pressure valve in the radiator cap should never relieve after shutdown. If it does that's a sign the system is over pressurized, usually by combustion gases. The beginning stages of a BHG will cause this behavior. The valve doesn't pop off when the engine is running because the coolant temperature was kept low enough. After shutdown the gases in the coolant expand more than the liquid does as temp climbs and boom, the cap relieves. This usually happens after a hard drive or shutting down soon after being on the freeway. Either way it's a bad omen.
Click to expand...

I figured someone would type it all up for me. ;)
 
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jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
Well, you have to define overheating. If it's puking coolant out the overflow tank it's not normal. The pressure valve in the radiator cap should never relieve after shutdown. If it does that's a sign the system is over pressurized, usually by combustion gases. The beginning stages of a BHG will cause this behavior. The valve doesn't pop off when the engine is running because the coolant temperature was kept low enough. After shutdown the gases in the coolant expand more than the liquid does as temp climbs and boom, the cap relieves. This usually happens after a hard drive or shutting down soon after being on the freeway. Either way it's a bad omen.
 
Robogast

Robogast

Mechanic
Jun 14, 2006
58
0
0
VA Beach, VA
Hello, no i never did a pressure test. it usually overheated after i got on the highway for about 20 min or so. but it does work to turn the heater on full blast. im pretty sure it wasnt overflowing into the overflow tank. but the overflow tank was nasty so i cleaned it and i plan on getting a bigger radiator and a new upper radiator hose and i havent changed out all the radiator hoses yet. i didnt have enough time. the water pump is in better condition then the last. when i baught the car it didnt have a fan shroud. im not sure about the fan clutch. im not there to check it. i havent done a compression test either. i put a new thermostat in it, brand new water pump belt. the water pump thats on there i took off of my parts car but i inspected it and it was good. spun freely no wabbles.(like the one that was on it).and for some reason i dont know why but when i have the a/c on it makes my car stall. but i took the belt off. i havent been driving it lately because ive been deployed but ive been having my brother start it up every now and then.
 
J

jtran8

Supramania Contributor
Mar 29, 2007
199
0
0
wichita kansas
so are you driving your car without cooling fan shroud ? how about cooling fan clutch , is it still in good working condition ?( these two must have and must be in good shape and good working condition otherwise your car will over heat for sure ). Also when engine is cold , remove radiator cap and check if it fill up if not fill it up. If cooling fan and cooling fan shroud both bad , i would suggest electric fan.
 
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mkIIIman089

Supramania Contributor
Mar 30, 2005
3,061
0
36
Ohio
jtran8 said:
i would suggest electric fan.
Click to expand...
I wouldn't. And I > you. :)

If its happening on the highway, check the radiator to see if its full of junk blocking the air flow 1st.

The Fan/clutch/shroud/undercover combo is also very important, if you don't have any of those components (or if they are of questionable condition) you need to fix/replace/buy them.

Another thing, is the jiggle valve in the thermostat properly oriented?
 
bountykilla0118

bountykilla0118

In Pursuit of 500rwhp
Jul 16, 2005
1,088
0
36
40
Atlanta GA
jtran8 said:
so are you driving your car without cooling fan shroud ? how about cooling fan clutch , is it still in good working condition ?( these two must have and must be in good shape and good working condition otherwise your car will over heat for sure ). Also when engine is cold , remove radiator cap and check if it fill up if not fill it up. If cooling fan and cooling fan shroud both bad , i would suggest electric fan.
Click to expand...

Umm clutch fans are better than electric ones......

I have no fan shroud or under cover ...... I dont overheat. My 80 camero never had both either it never over heated. However it did have a fan that was belt driven without a clutch so it was pulling the max amount of air at any given moment. Hhhmmm I might do the same with the supra just run a fan without a clutch.

The only downfall i can see is that it will sound like a big truck :)
 
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