Engine temperature while towing

[tdouty]

I guess I'm old school, but I had always been taught that if the temperature gauge moves up towards hot, you pull off and let it cool down. I'm pulling a 32' Keystone Cougar X-Lite that is 6700 lbs empty so around 7500 lbs loaded in Pa. I had been pulling with a 98 Dodge Ram quad cab with a 318 and 3.73 gears and it was a all it could do. The maximum towing on it was 7800 lbs. I just got a 2006 Sierra 1500HD with the 6.0 engine in it and 3.73 gears. Pulling up a mountain at 65-70 mph in central Pa about two weeks ago, I noticed that the temperature gauge started at normal operating at just under the 200 degree mark; 260 is red hot on the gauge. The temperature went up to around 225 -230 and I didn't expect it to move much. I'm a bit worried because later this year we will be towing up the I76 turnpike towards Pittsburgh where the tunnel is. With my old truck I had to pull over and let it cool about 2/3 of the way up the hill (or did I?). I got the 1500HD to make sure I'd be able to tow the camper where I wanted to tow it, but now I'm afraid it might get too hot going up the mountain especially if it's hot outside.

I have a buddy who has a 2002 Silverado 2500HD with a 496 big block (8 litre) in it (only 40,000 miles and immaculate yet). He tows a 8400 lb camper that is about 9500 lbs loaded. He said that even with that truck it heats up on mountains, but has never once over-heated. He says it will go all the way up to red on big mountains, but doesn't ever overheat so he was saying not to worry about it because it can handle it.

I'm a bit worried about letting the gauge go that high to see if it can do it and not overheat. What are the experiences of those here? Is it normal to expect the gauge to go up near red and should I not worry about it? My tendency is to let it get up to maybe 240 and then pull off and let it cool down. I know turning off A/C and even turning on the heater can help so I'll turn off the A/C as a first step. Thoughts?

[tdouty]

It does have a transmission temperature gauge and if i remember correctly, it was around 200 which didn't seem too bad. I have thought about a bigger transmission cooler and will be keeping an eye on that gauge too. What cooler did you get for your transmission?

[lawrosa]

Most of the engine temps that rise on a hill are cause by the transmission getting hot. Most trans coolers are not big enough.

The reason why the engine temps rise is because the trans fluid goes through the radiator also. This makes the coolant hotter, hence the higher temps..

I installed the biggest trans cooler I could fit. My trans runs 180f as does the truck.

You need a trans temp gauge to know whats happening. If not your guessing.

And IMO if your truck was reaching 230F then your trans is the same or higher. The fluid will turn to varnish and youll be replacing the trans very very soon... ( About $3000 repair for the chevys)

I would change the fluid in the trans ASAP. Get a bigger cooler for the trans, and get a gauge for the trans and take it from there...

[MARKW8]

All the GM trucks have the clutch fan as standard. It can roar pretty good when it locks up. One thing about your truck, If your down to 2nd gear, the torque converter unlocks. This will build even more heat through the transmission and to the cooling system.

[tdouty]

Yeah, I'm not using the 318 anymore. I'm running a GMC Sierra 2006 1500HD with the crew cab 4x4 with the 6.0 in it which is pretty much the same size as the 360. That 318 was a strong motor! I'd run that thing hard and it never missed a beat. I did run into a case here about 2 years ago though where I got stopped on a hill and it couldn't go any further. It was just too much for it so I gave up on it and changed to 4 wheel low and towed it up the rest of the way in low range. It got me up the hill, but I was the slow man on the hill running the warning flashers. That made me think I either need to be more careful of the route I choose or get a different truck.

[Whiskey_River]

I had a 2001 Dodge with a 360ci & 4.10 gears. The temp gauge would also move higher somewhat under load. At the time I did some "google" search, 7-8 years ago. I found, don't know if its right or not, but the cooling in the 360 block had an area in the back that was close, or closer to the cylinder wall and had some type of pocket area in the back of the block that the coolant did not circulate as well as in other areas, thus under load would increase the temperature. I did add a bottle of "water wetter" as someone else recommended and it did help, and was only 10 dollars I think.
I don't know if the 318 block is the same as the 360, but it is from the same time frame.

[tdouty]

I do use the trailer tow mode and don't lug it down. RPMs are around 4000 to 4200.

[time2roll]

I have pulled 9 mile, 10%+ grades, low gear, 25 mph, full throttle, 115 heat, air conditioner on max, and the Ford gauge does not move :R

Anyway if yours stays 230/240 you are fine. What is your rpm when this happens because you should be 3000+ during a hard climb. Use your gears, all of them! Slow down a bit and drop a gear.

If the temp is approaching 250 I would slow up and drop down another gear. Last resort is low gear and turn on the heater but that is desperate. If you do pull off be sure to keep it running. Read the manual for best recommendations to sit in neutral or park, idle or fast idle etc. 50/50 coolant boils at 265/270 with a 15 psi cap.

Check options and specs for factory oversize radiator or larger transmission cooler if the trouble persists or gets worse.

[goducks10]

intheburbs wrote:
My half ton burb never moved the engine temp gauge. That includes pulls over the Rockies on the way to Yellowstone - 9600 ft pass - with the trailer below in my sig.

So far, the 3/4 ton is the same, though we've only pulled through the Appalachians so far. Will be doing the Eisenhower tunnel this summer.

It may not move till it reaches a set point. I had two F150 5.4 trucks. Used a scan gauge in both. The dash temp gage never moved even though the temps were going up on the scan gage.

Different story on my 12 Ram 2500 CTD. I watch the EVIC display with engine temp. I can see it increase along with the idiot gage.

[tdouty]

Oh and thanks for all the great replies! Great forum you have here!

[tdouty]

The thermostat is working correctly because with normal driving it's just under 200 which would be right for a 195 degree thermostat.

On the return trip I stuck to 60-65 up the opposite side of the mountain and the truck pretty much acted the same. I did have plenty of RPMs with the truck running about 4200 RPMs so there was plenty of fan and water pump speed. I'll pay more attention to see if I notice a fan kick on around 230 degrees on the next mountain I pull. Is there any way to know if it has one? Is there an RPO code for it or would it come with all towing packages from the factory?

[MarkTwain]

I don't know anything about your truck or engine, but I assume it has a thermostat, did you have it checked to make sure it was fuctioning ok. My Dodge 3500, 6 spd, tows a 14K 5th. wheel. My temp. guage never moves into the hot zone and just moves slightly above normal in all driving conditions, in mts. 8K to 13K high summer,freeway speeds.

[brirene]

I'll agree with those who are saying it sounds pretty normal. Those temps aren't THAT high, but you wouldn't want them to get too much higher.

[camp-n-family]

Pulling up a mountain at 65-70 mph in central Pa about two weeks ago,

There's the answer to your problem. Trying to pull 7500lbs up a mountain at 70mph is going to cause the temps to rise in just about any truck. Slow down, problem solved.

[MARKW8]

The temperature controlled clutch fan will not lockup until 230-235 degrees. The temperature should then come back down. This is normal as long as you hear the fan come on. It can be rather loud. My GMC diesel is this way.

Mark

[intheburbs]

My half ton burb never moved the engine temp gauge. That includes pulls over the Rockies on the way to Yellowstone - 9600 ft pass - with the trailer below in my sig.

So far, the 3/4 ton is the same, though we've only pulled through the Appalachians so far. Will be doing the Eisenhower tunnel this summer.