mrm1595

So driving around through the city the temp gauge is halfway but when i get on the freeway and drive a while it starts to get hot (about 3/4 way on gauge) but doesnt 100% overheat. Also, if i turn off the engine for a little bit and start it back up while its warm the temperature gauge will almost be in the red then slowly start to cool down once i'm driving again. Any ideas on what this could be or if any of you have had the same experience? Its not burning coolant at all so i figured the head gasket is ok so it must be the thermostat or the radiator.

Terrys87

iTrader: (1)

The temp gauge is not the best on these trucks. You did not say what year truck you have, but if it is the SR5 gauge, you can do the Definitive Temp Gauge fix on it.https://www.yotatech.com/forums/f116...ge-fix-271152/
I have had erratic gauges that just need to have the sensor cleaned that is in between cylinders 2 and 3 on a 22r motor. I just clean the crust off of the sensor with a brass wire tooth brush. Other areas to look at is your fan clutch which is a consumable part and can need replacing occasionally.

Since you posted in the 89-95 section, your radiator is probably in need of a good flushing. Take it to a radiator shop and have them to power flush it. I have mine done and they require me to pull it out of the truck and it cost $25 to have it done. The Preston kit that you can buy and flush your self just isn't good enough to knock out all of the crud that gets built up in them. I had a truck that it brought the temp gauge down a quarter of its normal reading just by flushing it.

How is your Thermostat and Water Pump?

mrm1595

Lol yeah i should have specified what i have. anyways, its a 94 4runner sr5 with the 3.0 3vze. I was going to replace the thermostat with a colder one (I live in PHX, AZ) and how could i check to see how the water pump is?

AdmiralYoda

In more than one vehicle I've had I chased my tail multiple times replacing parts just to find out the coolant temp sensor for the gauge was out of whack. You might want to test it out....there is a procedure in the FSM to check the resistance. Its a cheap and easy fix if its the culprit.

In my old Jeep Cherokee I put a heavy duty water pump, clutch fan, thermostats, new electric fan, HD radiator, etc and I was still running very hot. $600 later it turned out to be a $15 coolant temp sensor. Lesson learned. But I had a bullet proof cooling system after that though...

AdmiralYoda

Using a non OEM thermostat is usually not a good idea. If there truly is a problem it doesn't normally fix it. Plus if you make your truck run cooler than Toyota intended it will run like a turd and burn more gas. You are better off finding the exact problem rather than trying to throw band aids at it.