juice

I have a 2 part question here. First off I'm running a 92 runner with the 3.0 a/t 4" lift and 33's pretty stock except cold air intake. It has 93,000 original on it.
Question 1: When I got it I had to replace the tranny in it, was still running but the housing was cracked. so I put in a tranny from a 95 and the only difference was the neutral safety switch which I just took off the old one and put on the new one. At this time I also replaced the radiator, 180 thermostat, and added another cooling for the tranny line in the front of the radiator so it would run through 2, 2 being the stock one and the aftermarket one. well in town it would run bout 180-190 for temp but on the highway would get up around 200, then after a distance the tranny temp light would come on. Usually if I slowed down and let the temp drop a bit the light would go out or if I stopped, shut the truck off and restarted the light would be off. Any ideas as to why this may be?
After this I wanted to try just running with no thermostat and the results where the same with the exception of in town temp being between 160-170.
Question 2: It is now getting colder and want better heat in my truck in town so I put a brand new 180 thermostat in. Only now its running 200 all the time. I've tried 2 thermostats with the same result. Any ideas here would be much appreciated.
The coolant is full and no signs of BHG. And I've let it run plenty with the cap off to circulates. Maybe the thermostat isn't opening all the way? Since its on over heating I would think that it's open partially and or the rad fan is working properly.

camo31_10.50

i'm like...complete opposite...my 3vz runs cool...like on the VERY bottom of the temp gauge.

and when i let it idle for extended periods of time (i.e. 20mins or longer.)...i've only let it idle that long ONE TIME..and the heater WAS NOT on lol...i took off down the road and it quickly came back down to normal.

sam333

Did the transmission overheat( light go on) before the extra cooler was added? Why did you replace the radiator? I would remove the extra cooler. I would try to separate the two problems( is it the engine overheating the trans, or is the trans overheating the engine). Running without thermostat is never a good Idea. The thermostat is there to get the engine up to the proper temp quickly and keep it there. The engine temp affects more than just the heater. It affects how the engine burns fuel, wear on the engine, and affects how computer operates the engine( coolent temp sensor). The temp rating on the thermostat( best engine operating temp) , is just the temp that the thermostat opens at, and trys to maintain by varing the amount it opens.The thermostat only has control of the coolent temp up to its opening temp( 180 derees ect). Once its opened all the way , its up to the rest of your cooling system to keep the coolent temp at that best operating temp(180). So I would look at the rest of your cooling system first, staring with your extra trans cooler ( is it blocking airflow to your radiator?) Hows your water pump? Did you flush the system when you put in the new radiator. Hows your electric fan? Did you put in a new radiator? Sometimes a blown head gasket is hard to pinpoint because the leak is so small. You can have a sniffer( senses combustion gases) used on your radiator, and it will tell you if you even have the smallest head gasket leak. l

juice

I put the radiator in before the tranny. the truck was over heating before I found the crack in the housing in the tranny so I replaced the tranny. the temp light for the tranny came on before and after the extra tranny cooler, but only at highway speeds. So like I said before with the thermostat in running 180-190 but now running 200-210. Just dont know whats up, I've been through the hole process of "bleeding" the cooling system and here we are.

DIRT CLOD

FIRST: if you aren't certain it has been done, call your local toyota dealership service dept. and tell them you would like to see if the headgasket recall has been serviced on that VIN. These engines are notorious for head gasket issues and toyota foots the bill if your car hasnt had it done.
Check to see if there are any obstructions or kinks of any nature in any of the tranny cooling lines.
Turn your heater on High when you are going down the highway and see if temp. goes down, then at least it's localized to the cooling system. I have had a few issues with the cooling system in my '92 as well, only mine is manual.
Water vapor at the tailpipe? hold a peice of glass or mirror in front of tail pipe and see. This is a good indicator of head gasket issues as well.
my $0.02 anyway

juice

thanks thats a good idea to call the dealership, I forgot bout that, but being a 92 if it hasn't been done do you think that they still will honor it? it does only have 93000 on it. and I've been leary bout the HG issue any way and constantly monitoring it and right now its 20's and 30's here in Iowa and the only water I notice at the tailpipe is at start up and its all water and not that much, could this be an BHG issue? But at the same time the coolant always appears to be at the correct levels

DIRT CLOD

they have to honor it if it has never been done. No matter if it has even 226,000 miles on it. the issue was with the gasket materials, the ones that came with the engine from the factory wene not up to par material wise....I hope this helps you, let us know what you find out.

DIRT CLOD

I had a 77 toyota tercel , good lil car, that i bought in 1990 for $75 and the rear control arm had snapped. I sold it to a friend for 100 and he was driving it a week later. I asked him how much he spent (i mean come on its a $100 car). He called the dealership to price it and found it was a recall. Toyota came to his house, towed the car to the shop, replaced whole assemblies both sides, no bill....I was pissed..lol

juice

I called them today and they said it had been done back in 97, not sure how many miles where on it then but its only got 93000 now. lol that sucks bout your tercel but atleast you made 25 bucks on the deal.

sam333

Your truck( cooling sytem) really isnt running that hot. But the trans temp light is a problem. The two may be related or not.

I would pull the trans temp switch if you can, and test it( as per the manual).Or try heating it up and see at what temp the light goes on. It might be bad and you dont really have a overheating problem. Normal operating temp for the trans should be around 200 degrees( at the sump).You can always add a trans temp gauge too.

One of the best tools I have is a IR heat gun, just point , pull the trigger and you get instant and accurate tempratures. If you are over 200 -220( at the sump) on the trans, its to hot.

If the light is accurate( good) or you check it with a IR gun and the trans temp is to high, I would do what DIRT CLOD said, and check for obstructions( dents, kinks) in your coolent lines or anything else that would affect the flow through the coolers.

Check( smell) your fluid, to see if it smells burnt. Make sure the trans is not coverd in dirt /grease ( harder to disapate heat).Pull the pan change the filter and what fluid you can.

The trans could be going bad and that is whats causing the extra heat.

On the engine ( other than the obvious stuff, like coolent level, slipping belts)I would check your fan clutch( no oil leaking or spins to easily).Electric fan comes on at around 220 degrees. If you have an IR gun you can test when the thermostat opens while the engine is running. Vent hole in thermostat. Water pump ( vanes broken or eroded , pump housing eroded).

You said you replaced the radiator . Did you buy a new one ? If not. Again you can use an IR gun to check the radiator for blockages( any large temp differences in one location).

If your cooling system was negleted before you bought the truck( not changing coolent or running water) the walls of coolent passages can be coated with rust / minerals, that really cut down on the flow and the the transfer of heat to the coolent .

I would also check your timing and exhaust back pressure.

You can also check for a blown head gasket your self by renting or buying a coolent system pressure tester. You can have a leak just from your combustion chamber to your cooling jacket and not the other way round( so no coolent in your cylinders or oil , just pressurized /heated coolent.)

juice

Great info sam thank you. I will try the pressure test just to make sure that the HG isn't blown. And I've been meaning to install a tranny temp gauge just like u said but haven't gotten around to it, I messed up when I put in aftermarket gauges in the passenger side part of the dash and didn't leave enough room to put one but its time to make a spot I think. It just would be nice to know exactally what temp it is running thats why I like the coolant gauge I installed. Others have told me that 200 isn't high too, but its just that it didnt' do it before and now it does. I've been wanting to go with an electric fan too but been waiting on getting other stuff done first, might have to push that up on the priority list as well. But one thing with the tranny light, when I shut the truck off and turn it right back on the light is out, wouldn't that lean more towards an electrical problem? But on a side not I did come to my detroit ez lockers sitting at my door step.yahtzee. Gotta get this stuff figured out so I can lock the front and rear