New Here, Need 4Runner Temp Help Please

J

jnettrecker

New member
Although I am not new to Toyota (had several pre 1994 trucks), This is my first 4Runner. 1997 Limited 4x4. Very pretty vehicle and I'm ashamed to say I bought it for running feeders on the hunting leases. Truck is running fine but I have a technical / overheating question. The radiator had a very slow leak when I purchased it. Bought it, Filled it up and drove it home. Lost a little fluid but factory dash temp gauge never went over 50% and everything was fine. Installed new radiator and used O'Reilly UNIVERSAL 50/50 antifreeze mix. Topped everything off, ran the motor until the thermostat opened, topped it off again and filled reservoir to the correct level. Truck set for 2 days, fluid level had not moved. Drove truck into town (+/- 15mi) Set in parking lot for an hour and then back home. Now keep in mind it was 105 here today in TX, but on the way home I noticed the temp gauge was near the red square box at the top of the white area. Not touching the red butt but definitely closer than I have ever seen. I got out and checked......no leaks, everything seemed normal, just hot under the hood, well technically it was hot everywhere, and the black asphalt wasn't helping I'm sure, got back in and drove home. Gauge Stayed there the entire way home. Got home, let it cool down all the way, coolant level in tank was the same and radiator level is full. Is it overheating? What is a normal running temp for this truck? Thermostat seemed to open about the right time when I was doing the fluid fill. I do have an infrared temp gun to check things, just need to know the parameters.

Any help is appreciated! Thanks in advance for your help.

Note: I'll be selling the running boards if you know of anyone looking.
00404_30FPwzHblC0_600x450.jpg
 
Register to hide this ad
My Ultragauge puts me at 201.Xx sometimes but usually I run between 197 & 199

I ran a couple hours on the interstate last year in some serious heat. It got as high as 213
 
What kind of radiator did you install? Also, It shouldn't hurt anything to run on others but these things really love running on Toyota Red. Especially in the higher mileage trucks.

I will add that my typical reading on my ScanGaugeII is around 165-180 every day. I also have a TRD ext. cooler though. I usually wont see anything above it unless I'm doing very low speed up and down driving which is mainly offroad.
 
Last edited:
You don't say that the fan is running... is it?

From your descriptions I am simply guessing that the fan clutch may not be engaging and the truck is simply using moving air to cool it and not getting the benefit of the fan.

I realize it is too hot to be running without air conditioning but try that for awhile to see if that affects the temperature gauge.

And of course it is way too hot out to be running the heat, but do so for a bit and see if that affects your temp gauge-be sure that your circulate the new antifreeze/water mix all throughout the system.

You'll get various opinions on the cost versus benefit of the Toyota red coolant but if you have mixed your new coolant with it some would argue you are inviting trouble.
 
Ron Helmuth said:
You don't say that the fan is running... is it?

From your descriptions I am simply guessing that the fan clutch may not be engaging and the truck is simply using moving air to cool it and not getting the benefit of the fan.
Click to expand...

I 2nd the fan not engaging properly. I would also wash out the coolant you just put in and get the toyota stuff.
 
I grabbed my temp gun and went for a drive. The temp gauge would almost peak out then take a dive as if the thermostat had opend up. The highest reading I ever got on the motor itself was 209° and the hose coming out the top of the motor into the radiator was 190°. I'm thinking a thermostat? The gauge would literally go down to about 1/2 taking 30-35 sec to go down then slowly creep back up over 3-4 min. The fan is running like crazy. If it were any more engaged we'd be preparing for lift off, lol. Anyone know if the t-stat is an easy swap?
 
sure wouldn't hurt to change out the thermostat but it almost sounds like you have a bubble in the system.

Never done the t stat myself but I'm sure there are threads out there about it

thermostat change 3.4 v6

yota tech has one or more
 
So you said it was fine until you worked on it The radiator and antifreeze. A no-cost test would be to put the old radiator back in and see what you get. Should only take a couple of hours. You have already done it once.
 
Last edited:
Well the other radiator is long gone. Thinking I may try to just pull out the t-stat until I can get to town.

Another thought, I just bought the truck so I don't know it's history. Is it possible it was already running hot, I just never saw it since the system didn't pressurize on the way home?

Now my wife's RX-8 has an AC issue......not my week, lol.
 
I second the thermostat. The way the temp is diving and then creeping back up, sounds like a thermostat that's hung up. And it's low cost so you might as well replace it. Keep us posted.
 
Well the job is already done and I just read that post....... I replaced with a 180° from O'Reilly. Jiggle valve was at 12 o'clock on the one I removed so I re-installed the same. Is factory 6 o'clock? No more diving on dash and sitting there idling for 30min in 95°+ ambient temp & dash gauge never went over 80%. Also held laser temp gun on exit hose for nearly 5 min. At the hottest point with me revving engine to 2,000 rpm it hit 200.4 but was normally between 178°-186°. I need to go drive it but I'm thinking that was it.
 
IGNORE that last post. Major overheating issues still. Is it possible for the truck to be running perfectly smooth and have a head gasket issue? I was able to identify some additional items that may help.

The faster I go 65+mpg the higher the temp gauge goes. When it hit the red block at the top I pulled over, ran around to the front and shot the engine with my temp gun. Radiator 167, engine 200. It gets hot at the weirdest times too, like going down hill at 55 (in overdrive)s. Just for kicks (cause I was getting aggravated), I floored the truck. It downshifted and the temp immediately started to drop. Truck is pristine but I'm at my wits end with this overheating thing.

:frusty:
 
Ive replaced all the anti-freeze with Peak (the one for imports), replaced thermostat dongle at 12 o'clock, replaced radiator (note: radiator was leaking when I purchased the truck so I changed it the next day. Did not notice it overheating on the way home). Fan is blowing strong and I've opened the heater valve to flush out any air bubbles.

Is it possible for the water pump to stop?
 
You must log in or register to reply here.

Members online

No members online now.
Total: 169 (members: 0, guests: 169)

Forum statistics

Threads
278,306
Messages
3,554,045
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top