How hot does your 4R run usually?

[nacho]

The needle on my temp gauge seems to be on the high side from middle all the time even on cold days. Is that normal or should the needle be more on the lower side or right in the middle? How hot of a thermostat do most of you run? I was thinking about going to a 170' thermostat to see if that lowers it some.

 

[quicksilvr]

The needle on my temp gauge seems to be on the high side from middle all the time even on cold days. Is that normal or should the needle be more on the lower side or right in the middle? How hot of a thermostat do most of you run? I was thinking about going to a 170' thermostat to see if that lowers it some.

Using the needle as an indicator is basically worthless. You really have no idea how hot it is, based on the needle position. It could be 185 or 205, and the needle could be in the same place.

You need to get an OBDII tool of some flavor, and see what it's running that way. After that, make a decision.

My truck runs between 185 and 192. My friends '99 consistently runs 200-205. I think anything under 205 is fine.

 

[Qyota]

Mine runs between 197 and 205, usually, as indicated by the SGII. As high as 209 once. It's weird, even on really cold days (15 or 20 below), the temp will get up over 200. That's why I'm doing a cooling system overhaul this spring. New radiator, hoses, thermostat, gaskets, etc. I don't like to see anything higher than mid 190's. Not sure why it runs so hot.

 

[ironhippy]

According to my scangauge II my 2000 rarely ever goes above 195 and I've never seen it above 197

 

[econhonda]

Never been above 193.

 

[Qyota]

Yeah, that's why I think the cooling system on my truck isn't quite right. I hope it's not a restricted coolant port somewhere in the block.

 

[rjaudi]

I just got my scangauge and am getting consistent 204-206 degree temps. My radiator is a year old, new coolant, new water pump, and thermostat is 1 year old. Any ideas on why I am running this hot? I do have the tranny cooler mounted in front.

 

[cosmos7]

My 2001 with supercharger warms up to 199 degrees and seems to stay there no matter what it's doing. When I first bought the vehicle it was running screaming hot... I noticed because the hood would be too hot to touch. Turned out to be cracked hoses but that stupid needle never moved from the middle, which is why I bought the Ultragauge.

 

[02SE]

The factory gauge is really just a glorified idiot light. On mine, it's up to 'normal' temp by 158° F and stays there without moving to at least 205° F, according to my Scangauge.

As for temps when warmed up, it's usually between 188-193° F. The 205° F reading was on a very hot day, while climbing a steep hill in 4 low.

This is with a manual transmission. For an automatic with the tranny cooler built into the radiator, and/or auxiliary cooler in front of the radiator, normal operating temps might be a bit different.

 

[quicksilvr]

I wonder if the 200 range is pretty normal for these 3.4 auto's.....

I know my thermostat has been replaced, and now I don't wonder if the previous owner replaced it with a lower temp one, since I probably see 185-190 80% of the time. The other 20% I get up to 195 tops. I've never seen 200.

But like I said, my friends nicely maintained '99 reads 200+ all the time.

 

[nacho]

Considering that water boils at 212* it seems like these engines are all running a little on the hot side. I guess the engineers knew what they were doing, but it seems like a cooler running engine would last longer.
Has anyone ever put in a cooler thermostat like a 170* one?

It sounds like most everyone's temp gauge reads close to the middle no matter what their true temp really is. Interesting. I can never get a straight answer to any of my questions from my local Toyota dealership tech guys. That's why these forums are so great.

 

[quicksilvr]

Considering that water boils at 212* it seems like these engines are all running a little on the hot side. I guess the engineers knew what they were doing, but it seems like a cooler running engine would last longer.
Has anyone ever put in a cooler thermostat like a 170* one?

It sounds like most everyone's temp gauge reads close to the middle no matter what their true temp really is. Interesting. I can never get a straight answer to any of my questions from my local Toyota dealership tech guys. That's why these forums are so great.

Yeah, but a pressurized system raises the boiling point of water considerably. I think a 16lb radiator cap adds 48 degrees to waters boiling point. Not to mention the fact that it has ethylene glycol in it....


Your coolant won't boil till at least 260 degrees F if your system is functioning correctly, probably higher.