Slightly overheating after prolonged idling

Truck engine slightly overheated after prolonged idling. Temp goes down within seconds if I press the gas just over 1K rpms. Ambient temp is between 85-100 F. Coolant level good, oil level good. Pressing the gas (higher rpms) will result in higher pulley speed which will cool down the system but should the ECU take care of it and should I be concerned about radiator fan clutch (considering high ambient temperature and pronlonged idle time of 1-2 hours)? What other things would you check on? Note: it’s does not completely overheats even if I don’t press the gas.

 

That's not overheating, and idling @ 100° that temp wouldn't worry me.
Without the forward air flow, I'd actually expect it.

Is idling for hours on end something you do often?
If it was my truck, and it was avoidable, I'd avoid it.

 

Until it gets in the red part near the "H", you have nothing to worry about.

 

100°, a mechanical fan, and idling for 1-2 hours? Yea, it's gonna get a little warm. As long as it isn't near the red zone and the dash isn't warning you you're good. I would however change the oil more often if you idle like that a lot.

 

The current condition is still safe as others said. However, your fan clutch may be slipping or you may have mud/debris packed between your condenser and radiator. Usually the fan clutch fails the other way (fan doesn't slow down when coolant is cold) but I guess anything can happen.

Did you have A/C on while idling? The idle rpm should increase with A/C running.

 

Thanks everyone for the replies. It has done this before but the temp gauge needle was just slightly over which was not concerning to me (see pic example). The more recent times it has done it, it’s been slightly higher than usual. Note, it does not do it often, only when idling for longer periods of time. Unfortunately, I do run it like that 2-3 times a month since I cross the border very often and during holidays the border crossing lines can get long and slow.

Although, I am not concerned anymore. Is there any recommendations to make sure I’m keeping my cooling system as efficient as can be since it’s a hot summer and I have to run it on idle frequently?

 

Just make sure condenser and radiator is clean, and you keep up with the maintenance, maybe on the short/sever duty side since you are holding temps without airflow. There's a sticky with a maintenance map outlining it all.

 

Thanks! Forgot to mention that I recently started hearing a belt squeaking noise during cold start. I tried replacing all idle pulleys but the Gates were not designed as the OEM and didn’t like them so I installed the OEMs back with a new belt. Noise went away for a while and I can once in a while hear it again during cold start but only for the first few seconds. Not sure if the belt slippage can be a factor as mentioned in one of the comments.

 

OP, out of curiosity, how many miles does your truck have?

I don't think I've ever seem the temp gauge move in a modern car - I've thought many newer cars have idiot lights in gauge form.

 

Plan to replace the fan fluid coupler

 

I’m amazed that people even look at the dash temperature gauge. To me it’s like the tachometer or inclinometer. They pass time when you are bored, but not otherwise useful.

 

You could always upgrade to a bigger radiator if you live in a hot climate.

https://csfrace.com/csfs-high-performance-radiator-for-2nd-3rd-generation-tacomas/

 

Welcome to the forum

 

It's rocket science

 

Not to worry you, and it’s minor so far, but yeah, that’s higher than mine when I’m sitting there idling for extended time in 100 degree plus days with the AC on or even when towing with a 4000 lb trailer.

I did put an electric pusher fan on it to help the AC blow cooler while idling, that may help yours also. I don’t think you need a larger radiator, but I’d do or get a thorough radiator back flushing and have your regular fan fluid coupler checked as mentioned by Vlady.

 

Move to alaska

 

130k

 

IMO, and one of the first things I did was get a OBD2 reader and Torque or get a Scanguage or other and get the accurate temperature rather than relying on a "dash gauge". I could tell exact temp and know the thermostat was working and at what temps. Overheating once will ruin your day.

 

Wouldnt hurt to wire in an electric fan

 

FYI: Toyota had a TSB a few years ago (tsb-0063-18) in hot climates where they acknowledged airflow and they fixed it with a kit to add an electric pusher fan. If there isn't enough airflow for the AC, I see it affecting general engine cooling.