Temp Gauge Reading

[bohemian]

On a recent 1000 mile plus trip through Central Calif I was a bit concerned about the temp gauge reading

I am driving a stove stock 2000 4 Runner with 150 K in excellent plus condition with a recent service that included coolant change...
5 speed trans....

Travelling at 75 plus in 5th
Outside temps around 100
Air on
Roof rack but no load
Driving alone no passengers
200 pound cargo inside...

After a time the temp gauge needle would move from its usual place at dead horizontal to about half way between there and the red zone.. or about 1/4 inch away from the red...

I never let it get any higher

When it got to this point I would switch off the air and turn on the heater full blast which brought the temps back to normal. ( this is something I have been preaching to my kids for years)
I would repeat this process as necessay...
Going up long grades it obviously heated up quicker and down grade cooled off quicker

The question is... normal for a 4 Runner or not...

If this were another vehicle I would be looking at the coolant level ( which is at the top)
Loose H20 Pump belt ( it is not loose)
Bad fan clutch ( seems to be good)
Slightly plugged radiator... doubt it.. fluid is clean and new
Thermostat sticking closed

However if any of those conditions existed it would heat up at other times and does not

I took a 50 mile trip today in 85 dgree weather, both open road and town ,and gauge stays at normal......

Any observations here?
Was it simply hot out?

Toyota Serv Mgr says he has a 2001 and the needle never budges in similar circumstances?

Appreciate any input

Thanks....

 

[004Gunner]

Since you checked the rest, I would check or just replace the thermostat. When the coolant was replaced was it a flush or drain and fill?

 

[bohemian]

The service was done about 1500 miles ago.
The price indicated flush.. but who knows

For a thermostat to be at fault it would be failing in a closed position..
I'll pull it and see what's up

I have driven it today in "normal" conditions in 90 degree temps with no repeat of yesterdays events.


I usually do all of the auto servicing and repairs but the FBU decidied to have this major service

then she bought a new Highlander and "inherited" the 4 runner

Last time I had a similar situation on a 1982 4X4 Toyota pickup
it turned out to be 2 things... fan clutch was toast and the radiator was
a bit plugged. I replaced them both.

Thanks

Jeff

 

[FoneRunner]

I've never had this issue with my 4runner, but my F150 started acting funny with the temp guage and it turned out to be a bad ground on the electrical system...it only affected the temp guage and nothing else. I added a ground strap and it's never given me another issue. Failed emissons one year cause of it though....that's why I remember it. Hope that helps...

 

[96743runner]

Never had this problem with my 4Runner either. My temp. gauge needle never goes past the halfway mark. On my scangauge, it says that the temp. is 188 degrees and it also never runs hotter than 188 degrees.

 

[juiceboxer]

I was towing my boat through vegas in 120 degree heat and my needle never budged past halfway. That was with the air cranked, Headrest T.V.'s running, sub blasting, etc. I was shocked at how well these thing stay cool. I would check the thermostat first, then go from there.

 

[bohemian]

For drill, if not to correct this condition, I'm going to change the thermostat

Thanks for the replies.