I have been towing my toyhauler lately in some hot Texas summer heat. My temp gauge seems to stay around 205 to 210 almost constantly. Also my A/C doesn't run as cool as it should when it gets over 100 degrees, imo. IS this ok? The Cummins seems to be fine, plenty of power etc.

Is our stock thermostat a 195? Has anybody switched to a cooler one, say 185? What effect would that be on my temp gauge if I am already reading 10 or so degrees higher than the current thermostat?


Thanks in advance.

 

I have a 180 stat from Cummins and I ran it on my 03. It kept my temps much cooler than the stock unit. My new truck stays nice and cool right now so I have not installed it yet. IMO it's worth it if your truck is running warm. Are you sure your fan is engaging properly?

 

If your truck wants to run at 205-210, it will even without a thermostat.

 

DZ.....I guess my fan is working because when im not towing I don't notice it staying at 205. It only stays that warm when it's working hard in hot 95 plus temps.

If it wasn't working I would think that it would get much much hotter very quickly. NO?

 

Ok, so there is no need to switch the thermostat then right? The 205ish is just normal and not hurting anything over extended periods of time?

 

205 is not bad if you are towing when it's that hot out. If I was doing that a lot though, I personally would prefer cooler temps if possible. That's why I have the 180 stat..

 

Mine runs right about the same as yours is in the heat over here in NM. If I was towing all the time I'd go to a 180* t-stat, but it IS possible that the truck would still run the 205*'s anyway.

CD

 

I thought these trucks were designed to operate at 205-210 because of the 3rd injection event and burning all fuel in the chambers??

 

When I ran my 180 stat in my 03, my truck never again saw 200 degrees except one time when I was trying to back my 10,000lb trailer through a very muddy yard where I had to use 4wd to get in. Now that was fun.......

 

This assumes that the thermostat is fully open. My guess is it is not fully open. A new thermostat is inexpensive and would answer the question in short order.

 

The CTD runs more efficiently when hot, and has a large reserve capacity built into the cooling system. The fan clutch shouldn't engage until well over 205*F, and it's obvious when it does from the roaring sound audible over the engine noise/exhaust.

The only time we've been able to make the fan clutch engage is at high ambient temps of 90*F+ with a couple gallons of coolant drained from the system... 230-240*F seemed to be the threshold for partial fan clutch lockup.

 

A product that is new to the Market is the ROYAL PURPLE " Purple Ice" additive. Several on here use it with good success. I have 2 bottles in my new 07 as we speak. Temp still runs the same when pulling, but as soon as you level off on flatter ground it immediatly pulls the Temp down 10 degrees or so. Truck used to take a few miles to cool off. Might be an option for you..

 

Purple Ice has been around for a while - we put it in the '98 several years ago - and it does work as advertised.

 

I appreciate all the comments. I will probably go ahead and change out the thermostat at my next self-imposed 20,000 mile maintenance service interval.


I wasn't really concerned that the truck was overheating, but if heat is the engines enemy............I'd prefer it to stay under 200 degrees if that is possible and practical. I've wondered too if my Ranch Hand Full Front Replacement bumper (and winch) might even be blocking some air flow thereby making it run warmer.

When accelerating hard (non-towing) in 95-100 degree temps, I notice the temp will go slightly over 200ish....then go back down. But while towing heavy on the highway, it just seems to stay around 205-210ish all the time when the ambient temp is hot.