Engine and Trans temp running hot

[delongboy]

Hi, I am a newbie to this board and a newbie to pulling a travel trailer.  I have a 2008 Yukon XL Denali and we just upgraded our 1995 coleman popup to a 2004 Jayco 27BH.  The tow rating on the denali is 7900# and it pulled the 1900# pop up without even know it was there.  However on our first long trip with the jayco loaded to about 6500# (which should still be fairly under the tow rating) I started running into hot engine/trans.  I was watching the trans temp and if I would cruise at about 65mph the temp would start climbing.  It would get to about 210 and then the engine temp would start going up too.  At this point I would dial back to about 50-55 mph and the temps would come back down some. the engine would return to normal which seems to be right around 212 but the tranny would stay in the 190's.  I had it in tow mode the entire time.  We were going over some Va mountains but nothing too serious.  The engine seemed to have plenty of power and pull with no problem.  I am just wondering is this something to be concerned about or is it normal?  I believe it does have an aux tranny cooler.  Should I look at upgrading that or adding another?  This being our first trip in this camper it was packed fairly light, and I am worried as we begin to accumulate those camping "necessities" that the weight is going to be more of a problem.
Thanks

 

[Utclmjmpr]

You no doubt have a lot more frontal area on the Jayco that the pop-up, plus, have you checked the outside temps lately?? slowing down is allways good.>>>Dan (now add in the Yukons air conditioner)

 

[delongboy]

So you are saying this is to be expected?  Just slow down an maybe turn off the air when it starts heating up?

 

[tvman44]

I would add a larger aux tranny cooler, especially with the hot summers we have now..

 

[glockholiday]

The auxillary tranny cooler is a great idea. But you are still in the normal range. When towing my engine temp runs 195-210 and my tranny runs 190-230.

 

[Utclmjmpr]

Your poor cooling system is working itself to death to handle all these heat sources at once, engine, producing heat,  trans, producing heat,  air cond. producing heat,, at mid day temps yet..
Its a problem we have had since cars have been made. The extra frontal area is a major consideration.>>>Dan

 

[lone_star_dsl]

190 for the trans is ok.  Most use 225 as the red line for transmission fluid.

As far as engine temp, perhaps try a cooling system flush.  Maybe have the thermostat checked as well.  Also, take a look at your radiator and what ever is in front of it to make sure it's not plugged with bugs or debris.

 

[camr]

I would most definitly ensure that an external transmission cooler is installed. I have a Transcool installed on my 09 Buick Enclave and have had no issues pulling a 26 foot Heartland Edge on level prairie. No hills but LOTS of wind. The installation cost me about $300 and it is a small percentage of the total unit cost.

 

[eddieelk]

Years ago I pulled a 29 ft. Coachman with a '76 Cadillac sedan.  I took a condensor from an old refrigerator and mounted it in front of the radiator.  I cut the lower(input) cooler line inro the radiator, and used power steering hose to connect the condensor. It added an extra quart of fluid to the system, and it never overheated. The only expense was the hose and clamps. Eddie Elk.

 

[Gary RV_Wizard]

190 is ok for the tranny, though I would recommend using a synthetic tranny fluid if it doesn't already have it. 212 is ok for the engine. You have to expect tranny temps to rise when towing a heavy load - it is working hard at any speed. I hate to see it go above 200-202, though, even with synthetic.

You are already at/near your max tow rating. The 7900# rating is for an tow vehicle that is empty except for fuel and a 154# driver. By the time you add passengers and gear in the Denali, including the hitch, I'll bet the amount left for the trailer is no more than 7200 lbs.

So you probably need to stay under 60 mph in the hills.

 

[Mopar1973Man]

Like towing my Jayco around Idaho if I attack a grade full tilt I see a rise in EGT (Exhaust Gas Temp), and Coolant Temp on the diesel... But now drop from 5th to 4th cruise at about 45-48 MPH over a grade the engine temp never moves and EGT's are very controlable. So speed is your biggest problem. I tend to agree with Gary...