86 Pickup-Overheating - Toyota Nation Forum : Toyota Car and Truck Forums

bvenvert · 03-07-2005, 10:35 AM

I am looking for some assistance on an intermittent problem I am having with my 86 Turbo Pickup. It seems that I keep running into situations where my temperaturer gauge on my truck runs up to the hot range, but eventually the thermostat will open and the truck cools down. It doesn't happen everytime I use the truck, just on occasion.

My question is, could I have a potential cooling system problem that I am overlooking? I have changed the thermostat on my truck, three times in the past year. I recently drained the entire cooling system, replaced the radiator cap and replaced the thermostat for the third time, only to have the truck heat up again in the following week. I don't have any syptoms that there is a leak in the system or a head gasket problem.

Any suggestions?
Thanks
Bill V.

ModPod · 03-07-2005, 11:59 AM

Maybe it’s the water pump - just a guess.

texas12 · 03-07-2005, 06:22 PM

Is there any indication that it is actually overheating or is it just the guage reading high?
I had a similiar problem on my 4runner. Temp guage going near redline, not losing water, replaced thermostat, replaced temp sender. No help.
Just recently, I replaced my cluster, converting to tach, and now the temp guage slowly increases as truck warms and then stays in the center. I am guessing that the actual cluster temp guage was bad.

qsd-dan · 03-08-2005, 02:28 AM

[QUOTE=bvenvert]I am looking for some assistance on an intermittent problem I am having with my 86 Turbo Pickup. It seems that I keep running into situations where my temperaturer gauge on my truck runs up to the hot range, but eventually the thermostat will open and the truck cools down. It doesn't happen everytime I use the truck, just on occasion.

You're experiencing what is called "Temperature guage overshoot." Here is a site that goes into further details of this issue and how to correct it. Scroll down to where is says "Thermostat"

http://www.4crawler.com/4x4/CheapTricks/index.shtml

bvenvert · 03-08-2005, 02:28 PM

Thanks for the information. I was surprised to see that there was an actual service bulletin for the problem I was having. I think I am going to try to drill a small hole in the $4.00 thermostat I already have. As a a matter of fact I have two of them at this point. I will also call the local toyota parts store and see if they have the two stage thermostat and chekc a price.
Thanks Again
Bill V.

crazycruzer · 03-09-2005, 01:32 AM

I'm not sure about the engine running cooler with the thermostate removed? Thermostats help slow down the flow of the coolant so that it cools off in the radiator before it re-enters the engine. You can try buying a 170 degree thermostat to allow it to open sooner than the stock 180 or 190 degree thermostat during hot weather. Just remember to keep the 180 degree thermo and install it during cold weather. As far as overheating, I had that same problem with my old 90 Supra turbo MKIII back in the day. After spending hundreds of dollars replacing all types of cooling parts, I finally broke down and spoke with a Toyota specialist (now a very good friend and reliable source for auto repair). I was told that OEM head gaskets are weak and is a common problem in turbo equipped Toyotas. He recommended that I changed over to a metal head gasket and that should last a bit longer and allow higher boost. Sure thing, I no longer had overheating problems.

Phat_Phingers · 10-08-2005, 09:51 AM

My 86 22R is doing same thing, but I've had the water flow control for the heater removed and I'm getting an air lock in the heater line,(I've shortened the hose so its lower and its better now) Mines not just a guage problem cuz I also get now heat when the gauge goes past normal. Could the stat be in backereds? any thoughts?

subliminaltrips · 10-08-2005, 10:46 AM

could be backerdz.id pull out the thermostat completely as a test. it should not heat up much at all with it removed.if it does heat up without it id change your water pump... 26.99 brand new lifetime warranty at auto zone.... maby an hour job to replace. beck arnley has 160 degree thermos. i use one down here in fl. hell most people dont even run them down here.

bigturtle · 10-25-2005, 08:06 AM

y'know, it's just a shot here, but i didn't see a plugged radiator core mentioned anywhere.
i've experienced spot on identical symptoms in my '86 4x4 pickup 22r, listened to all the mechanics/toy buffs, learned tons about 'yotas still couldn't figure it out.....
i was talkin' to my mom on the phone and the subject came up an' she kinda blurted out sumthin' 'bout plugged rad. core- she was right. new core later problems solved! but thats just my personal experience. "bigger the variety of solutions-better the education for us all"guluk den.

99mustang232 · 10-25-2005, 09:17 AM

you can always get a dead part, you can test thermostats by putting them in a pot of water, then bringing the water up to that temp to make sure the thermostat opens, which is an easy test, hell someone could of even installed the wrong temp range... but this is a good thing to do to any thermostat prior to installation.

Yotalover · 10-26-2005, 08:49 PM

Big Turtle, I've had to replace two radiators on an '86 Toyota truck I've owned and driven almost daily since 1989. Both of these radiators were stopped up with ****. I wonder if this is a common problem with 22R engines? I use about a 50/50 mixture of water and antifreeze. Am I using the wrong kind of antifreeze?

osum · 10-27-2005, 04:28 AM

I had a heating problem with my truck too - it got hot even on freeway speed - so I replaced the radiator - that did the trick for me as well. Our trucks pre-88 are really old and a clogged radiator is a definitely possibility.

If not radiator and thermostat - you may want to check out the engine clutch fan, and hopefully not, a weak headgasket. It is the clutch fan, if it cools down on the freeway, but gets hot in stop and go traffic.

Road Wolf · 12-22-2005, 06:44 AM

I am having this problem, so I took it to a radiator shop and they said it was the thermostat, was fine for a day then started acting up again.

So I checked the fan and it was wobbling, so i replaced the clutch and it was fine until i jumped in the throttle and up it went.

So I yanked out the t-stat and it was bad (grrrr) so I put in a new one, and it still got hot when I drove it hard or pulled a load.

Then I noticed it was pumping the antifreeze out the overflow, and next was a new radiator cap to replace the other new one I had got when I replaced my radiator before I started having problems.

Now it will heat up from cold just before it reaches operating temp then settle back down and be fine, but I'm worried it will overheat if I have to push it, like going up a hill near my work.

I got a new water pump but haven't put it in, I'm thinking about putting it in and swaping the radiator for a new one and drilling the hole in the t-stat, but I may just try the swap and drill the hole and see what happens.

Does anybody have any other suggestions on this one?

Road Wolf · 12-29-2005, 04:56 AM

Well the t-stat had a hole already in it, but had a floating metal plug in the hole so I took out the plug and swaped out the radiator for another new one and it seems to fixed the overheating problem.

However it is still overflowing the overfill bottle and not sucking it back out, I'm thinking it may be bad hoses to and inside the bottle. Any other suggestions?