Running hot. Can not figure out why. 2J MKIII... 240* on the highway

[eman2289]

The car was running hot, to where the needle on the dash would be 3/4 of the way up, and sometimes even reach the red. The car was sitting for a few months, and i just installed an autometer mechanical water temp gauge with the adapter into the upper rad hose. When I did this, I saw how rusty and dirty the old coolant was, so, i drained it, used prestone flush, followed the procedure for that. I refilled with toyota red. I had the front end raised in my driveway.

I took the car out today for a test run and saw temps all the way up to 244 degrees. This was quite consistent, i blasted the heat and it was running at about 230.

I brought the car home, jacked up the front end about 3 feet off the ground, and tried to burp it again. I got a couple f tiny bubbles and thats it. I had the heat blasting and the car was at about 190. Took the car out, and the same thing happened, within 3 blocks it was at 220.

I have flex a lite fans, with a new stock radiator and an fmic. I could see how the car would run a few degrees hotter than normal due to the stock radiator and fmic, but I see no reason why it would reach over 240 degrees on the highway. Its about 50 degrees outside.

:1zhelp:

 

[jdmfreak]

Are you sure the fans are blowing the right direction? My last truck was doing exactly what you were describing and it turnedout the fan waswired backwords

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[mkiiichip]

How are you controlling the fans?

 

[eman2289]

They are pulling through the radiator. And they have a temp control box to come on at 200*

 

[mkiiichip]

Is it the style that has a probe in the fins of the rad? And 200* is a little high. You want something like, on at 190, off at 180.

 

[IJ.]

Undertray?

 

[eman2289]

Ill try to readjust the fans. But that doesnt solve my problem on the highway.

And IJ, what do you mean?

 

[IJ.]

Plastic undertray that goes from the Lip to the Crossmember, Mk3's WILL run hot at highway speeds if it's missing.

 

[eman2289]

Ive never seen an undertray... Pic? And would that really cause the car to run 50 degrees hotter than it should??

 

[Supra_Villan]

My car had no undertray and she never got hot, even with a small leak somewhere (birdcage would come on every now and again), and i drove it....well, like a 16 year old would a loud ass turbo car haha.

 

[IJ.]

Usually +5>10c but you might have a partially block AirCon condensor/rad so combined it's running hot.

 

[eman2289]

How else could i unclog it besides using prestone flush and then using a hose in the rad hoses, radiator, and head??

 

[IJ.]

Can take it to a shop and they can pull the tanks and rod it out, that'll cover the internal blockages, a lot of the time there's 15+ years of leaves and bugs in the fins of the rad and the AC core, time consuming PITA to clean out but well worth it.

 

[eman2289]

Its a new radiator...

 

[RacerXJ220]

Need better fans, or more of them.

Running an oil cooler should help.

 

[gurley0916]

I had the same problem when I went to electric fans on the stock radiator. This was when I was on the twins. I would fun 220 then 230 on highway with heater. I put the clutch fan back on and I never saw it go over 190 to 200 cruising. I know after a pull it would go to 210 for a while. This was with a under tray and fan shroud.

But Im single now and I lost my under tray and the fan shroud broke so now i am without both and I still dont see above 190 on the highway even after hard pulls. Most the time it sits at 185 on my gauge.

This is really weird that you are experiencing these temps on a single turbo. What CFM do your fans blow because stock clutch fan is around 3400 cfm on a mk4 setup. Might want to make sure you have more than that.

 

[AZN MK3]

check your radiator cap. If the rubber gasket is cracked or brittle it will cause you to overheat.. Make sure its a 14/16 psi cap as well. Hope that helps

 

[IBoughtASupra]

Fan clutch for the win. Reinstall it, you don't notice the minimal horsepower gained from removing it.

 

[mkiiichip]

I also had no undertray, and no temp problems.

You never answered my question about the temp probe. The cheap probes cycle the fans, while over heating, (while lowering coolant temps minimally (only lowering probe temps)).

While your at these coolant temps the fan should never shut off.

So is it a cheap probe?

IJ, I understand your logic, but the undertray is there for efficiency purposes, any setup should be able to keep the temps in check without it. (especially when the vehicle is undrivable because of overheating issues.)

I am still willing to bet that the OP has a probe in the rad to control coolant temps.

 

[eman2289]

Will a clutch fan fit on a 2J in an mkiii?? It doesnt seem like id have enough clearance...

---------- Post added at 12:10 AM ---------- Previous post was at 12:01 AM ----------

Im not sure of what type of probe it is, but the fans do not shut off until the car cools down to around 180 i believe.

EDIT: I see that it does fit. That may be my best option. Can I possibly use better e-fans? I dont wanna have to listen to the loud clutch fan...