jnettrecker
New member
Thanks in advance for any help or input and I apolagize in advance for the length of my post. Just trying to give you all the info I have. Honestly, I am at my wits end; although I used to be a motorcycle mechanic and have a general knowledge of wrench-turn-ology, I have very limited "acquired" knowledge of these trucks.
Vehicle:
I recently purchased this truck. It is a 1997 Toyota 4Runner Limited, 4x4 Automatic 3400 v6 w/ 226,000 miles. 1 owner, maintained at the stealership. All recalls done including head-gaskets. Runs perfect, no stutter, no miss, no oil in anti-freeze, no anti-freeze in oil (milky etc), no water vapor or strange smells from muffler (other than normal condensation), plenty of power, no funky hot or burning smells, and spark plugs look like new! If it were not overheating I would not be afraid to take this truck on a cross continent Safari. It truly is pristine!
Problem:
Dash gauge says truck over heats while going down the road. ONLY going down the road. Ambient temp while experiencing these symptoms range from 85F - 103F
-Let it idle, temp gauge only goes up to 50-60%
-Drive it like a hot rod, gauge only goes up to 75%
-Drive it down the highway at 70mph in OD and it hits the red block at the top in under 3 min.
I have taken my laser temp gun and shot the motor when it was at it's hottest points and the highest reading I have ever gotten has been 209F at the intake manifold and 187F at Radiator.
Interestingly enough I figured something out. If I keep the RPM's above 3,000 (manually shifting gear to gear) it never overheats. Matter of fact stays about 50%. I also discovered when I am driving in OD on highway and the gauge is nearing the danger zone, I can pop it in Neutral, raise the RPM's to 3,500 and it will drop to 50% in less than 10 seconds....... Whether or not gauge is reading accurate temps or not, who knows. However, I do know it is working percentage wise because results from all test have been consistent, not just a random jumping of the gauge.
Parts Replaced: (I know it isn't ideal, but so far All parts have been sourced from O'Reilly Auto as it is the only honest parts store close by, so my resources are somewhat limited. Toyota dealer is 1.25 hrs. Note: nothing I have done has changed the original symptom of overheating):
-New Radiator
-New 180F Thermostat (installed w/ dongle in 12 O'clock position)
-New Temperature sending unit (front passenger side of intake manifold under fuel rail)
-New 50/50 Antifreeze (O'Reilly Universal Coolant, this was the first thing done and made no difference whatsoever)
I'm thinking all I have left are the fan clutch and the water pump. I'm really tired of just replacing parts and would love some feedback on where I should go next or maybe a way to trouble shoot both of those items, or ANYTHING else I'm missing.........:redbrick:
Vehicle:
I recently purchased this truck. It is a 1997 Toyota 4Runner Limited, 4x4 Automatic 3400 v6 w/ 226,000 miles. 1 owner, maintained at the stealership. All recalls done including head-gaskets. Runs perfect, no stutter, no miss, no oil in anti-freeze, no anti-freeze in oil (milky etc), no water vapor or strange smells from muffler (other than normal condensation), plenty of power, no funky hot or burning smells, and spark plugs look like new! If it were not overheating I would not be afraid to take this truck on a cross continent Safari. It truly is pristine!
Problem:
Dash gauge says truck over heats while going down the road. ONLY going down the road. Ambient temp while experiencing these symptoms range from 85F - 103F
-Let it idle, temp gauge only goes up to 50-60%
-Drive it like a hot rod, gauge only goes up to 75%
-Drive it down the highway at 70mph in OD and it hits the red block at the top in under 3 min.
I have taken my laser temp gun and shot the motor when it was at it's hottest points and the highest reading I have ever gotten has been 209F at the intake manifold and 187F at Radiator.
Interestingly enough I figured something out. If I keep the RPM's above 3,000 (manually shifting gear to gear) it never overheats. Matter of fact stays about 50%. I also discovered when I am driving in OD on highway and the gauge is nearing the danger zone, I can pop it in Neutral, raise the RPM's to 3,500 and it will drop to 50% in less than 10 seconds....... Whether or not gauge is reading accurate temps or not, who knows. However, I do know it is working percentage wise because results from all test have been consistent, not just a random jumping of the gauge.
Parts Replaced: (I know it isn't ideal, but so far All parts have been sourced from O'Reilly Auto as it is the only honest parts store close by, so my resources are somewhat limited. Toyota dealer is 1.25 hrs. Note: nothing I have done has changed the original symptom of overheating):
-New Radiator
-New 180F Thermostat (installed w/ dongle in 12 O'clock position)
-New Temperature sending unit (front passenger side of intake manifold under fuel rail)
-New 50/50 Antifreeze (O'Reilly Universal Coolant, this was the first thing done and made no difference whatsoever)
I'm thinking all I have left are the fan clutch and the water pump. I'm really tired of just replacing parts and would love some feedback on where I should go next or maybe a way to trouble shoot both of those items, or ANYTHING else I'm missing.........:redbrick:
Last edited:
Thanks for all the help. I'll let you guys know.
