Ideal coolant temperature range for Gen3 Monty

[montero.life]

Hi,

I just picked up a 2003 Montero Limited. I re soldered the contact points at the back of the temperature gauge because the needle kept moving up and down giving inaccurate readings. Also, to be safe I picked up an Ultra-Gauge to see what the exact temps were through the OBD2. On this weekend's road trip (3 hours each way) and noticed that the temps were around 217F to 228F with the AC off. The 228F reading came only when I was going up one of the higher mountains. As soon as I started to descend the temp dropped again. This was also the only time I saw my temp needle move a little over the half way line.

The Ultra-Gauge has a feature that allows you to set an alarm for when the temperature hits a certain reading. Does anyone have an idea what I should set it at? Is 230F too high?

Thanks in advance.

 

[MontySquareo]

230f is fine, I'd set it at 220 just to be safe. Mines never gone past halfway except for before I owned it (rip head gasket) and when the thermostat died. Most engines won't fail before 240, so I go 230 max and get worried at 220

 

[montero.life]

230f is fine, I'd set it at 220 just to be safe. Mines never gone past halfway except for before I owned it (rip head gasket) and when the thermostat died. Most engines won't fail before 240, so I go 230 max and get worried at 220

Awesome. Setting it now to 220. Thanks for the info.

 

[montero.life]

This is the highest it hit this weekend.

 

[MontySquareo]

This is the highest it hit this weekend.

idling or hard driving?
does the temp gauge ever go past halfway (or is it broken like many of them are)

 

[SD_Montero]

I'd go through the whole cooling system for sure. 255 is way too hot

 

[Walrus]

According to my service manual, the thermostat begins to open at 82C/108F and is fully open at 95C/203F. Normal engine "Hot state" is between 80-120C/248F as defined in the service manual diagnosis procedure for an overheat/low coolant situation. (P0217)

220 sounds like a safe alarm point!