supra newb overheating
 

Hi guys.. I just bought a toyota supra 86.5 with some over heating problems. I have replaced the upper and lower radiator hose, radiator cap, thermostat twice (thinking the 1st one was bad), the headgasket and bolts are new and upgraded, replaced the water pump yesterday, flushed the radiator (with one of the bottles at a parts store), replaced the belts, and put in a new over flow tank. I felt the fan, the fan still has plenty of tension in it. The smaller fan works. Just put new radiator fluid/water in it and drove it to work this morning and it still gets hot.

When it heats up, its usually when I am at an idle and/or accelerating. It will go about 3/4 of the way up (20 min drive), then go back down and some times it even gets into the red (45 min drive) then goes back down almost immediately after. Then after a while, like the other night, it will shut off. When it shut off, the temp gauge showed just over the half.

The fan shroud is hanging pretty lose on the radiator by some duct tape (bought it like that). Newer engine is installed with about 50k miles.

Just a guess but you're about to experience a bhg.

Unless you have more air in the coolant system than you do coolant.

odd.. it just had a hks metal head gasket and arp head studs installed recently

But now that I think about it, i always hear a "gurgling" noise coming from the engine before it starts to get hot. But when putting the new coolant in i ran it and let it run the air out and put even more coolant in..

I checked for water in the oil and there wasn't any.

If I where you I would check the torque on the arp's whom ever installed it probably went with the TSRM 52ft-lb instead of torquing to HKS reccomended 72ft-lb. You wouldn't necessarly have a blown gasket but more of an undertorqued one. After that sit in the driveway and check the coolent then idle with the heater on and see if you get any bubbles in the radiator and check your passanger floorboard for leaks as well. If all that is fine then try to get it to overheat in the driveway by idling maybe you will catch something like a small leak from your TB hoses. It also might be overly advanced timing, reset to stock. Just some simple suggestions.

if you have done all that work by yourself, your not a newb haha. your well ahead of half the people that post here ;)

the gurgling means that air is somehow getting into your cooling system. one of your hoses might be a bit loose, allowing air to be sucked in, or you just didnt get all the air out in the beginning.

dont let the car get into the red...super, extremely bad things will happen. MKIII supras tend to blow something up if they overheat...they dont fare well with very high temperatures.

aer you sure the fan clutch isnt bad? and do you have a fan shroud on the car?

I do have a shroud on it, the duct taped one. the passenger side of the shroud is broke, so i can't bolt it in. (the whole shroud is still intact, just can't bolt it on)

I'll check the hoses again and see if the head gasket is torqued down enough.

The head gasket not torqued down enough makes the most sense to me

If you go with a metal headgasket you know that the head and block have to be extremely smooth and resurfaced very well. The metal headgaskets are more picky then regular headgaskets in that situation.

my fan shroud is just like yours, broke around the bolts and loose, and i havent had any overheating problems.

oops, didnt notice that.

+1...the head needs to be milled to a certain RA for the metal head gasket to seat properly.

The easiest way for the system to suck air is through the overflow can.

The engine spits and sucks into and from this can. If you keep it empty there's your pirate air.

ARP states specs of 70 lbs of torque. So if your mechanic can't read or follow instructions. Get one that can.

I used a 2.mm HKS stopper gasket. I torqued to 85lbs. But that's me.

when i first got my 87 supra non-turbo I had overheating problems too. Although at the same time my fan exploded and punctured my radiator. I thought that it was my fan clutch so i replaced the fan clutch, fan, and radiator and three weeks later the same thing happened. It turned out that all the trouble was due to me removing the plastic engine undercover. It caused the airflow into the engine compartment and through the radiator to be out of wack. IE. excess air flow from under the car into the engine bay and insufficient air flow through the radiator. That lack of air flow through the radiator is what caused my overheating problem. The excess air from under the car into the engine bay caused the fan blades to bend when driving and they hit on something (most likely the radiator) and broke off spinning about in the engine bay puncturing the radiator. Once i put the undercover back on i never had another problem with it overheating.

Although my 91 turbo doesn't have the undercover on it and i've got no problems with it. Nor does it have a fan shroud.

thanks for all the help.

What about the small electric fan in the front? It hasn't been coming on and yesterday it only heated up to almost 3/4.

If the fan isn't it, I will be checking out the head gasket problems.

some one suggested to me yesterday that i need to replace the fan clutch with a "flex fan".. has any done this? I have never heard of a flex fan.. looked it up and couldn't find much on it.