Okay, I have posted several other questions on here and I appreciate the help in telling the dealers what they can't tell me. I have been to 4 different dealers since I bought the truck in April (3 are due to where I was at the time).

So, I got the oil cooler kit and the EGR cooler replaced and subsequently added gauges this week, even though the truck in my signature is stock. I have almost 98,000 so pushing close to the warranty.

Now that I have gauges, I was towing my toy hauler (about 7,000 loaded) last night for about 550 miles from Billings, MT to Spokane, WA. The speed limit is 75 most of the way and trying to do that speed gets me horrible mileage and my EGTs are about 1,200. So that is fine, I stepped it down to 65 and got 10 mpg, though it adds 1.5 hours to the drive. LOL

So I want to know if my truck is running hot for a completely stock truck, no program or anything. The EGTs are basically a complete function of my turbo psi. If my turbo is at 10, I am about 1,000. If turbo at 15, then 1,100, if at 20, then 1,200, if at max of about 28, then 1,300. And the crazy thing is, if in town at 35 and psi at 10, I am still at 1,000 degrees. To me that seems excessive. Also, the fan clutch comes on every time the EGTs approach 1,200 degrees.

When pulling the continental divide, about a 10 mile pass with 5 miles at 6% grade, I was drafting a semi at 50 mph, needed 28 psi boost and running at 1,300 degrees.

So, this is what I am thinking. Either that is normal and I am making a big deal about nothing. Or one of two things, my intercooler/turbo is not working properly or my catalytic converter is clogged.

Please let me know what ya'll think. Thanks so much for the help!!

 

If your toy hauler is only 7000 lbs, that's a real small trailer! Have you actually had this rig weighed on a truck scale?

Where did you locate your temp probe on your manifold? Were you in tow/Haul mode? How long did it take you to get to the 1300*? It sounds to me like close to normal temps for a bigger rig.... I was coming back to from camping in the hils west of Baltimore and also hit temps of 1000* and over....never as high as 1300 tho. Went to 1200 once ... OAT was about 85-90 and hill was long and steep...5th wheel weighs about 8700#(loaded)..... had me and 3 passengers.

 

If you are getting 28 psi of boost out of your turbo then there is nothing wrong with either your turbo or your intercooler because if either was busted or had a leak then that kind of boost pressure would be impossible. While a plugged cat is certainly a possibility it tends to be rare on these diesels. Unless your coolant temp gauge is actually running hot I wouldn't be too worried about exhaust temp, for those vehicles I have driven with aftermarket egt gauges here in Florida, it is not hard at all to get up to 1200 degrees when you put your foot into it consistently.

 

yeah the claimed dry weight is 5,700 pounds and I had a 400 pound quad and a couple appliances as I mixed a dune camping trip in with the last of our move. There was no other weight in the bed of the truck or in the cab, was just me. It is a 27 footer, so looks big, but never had it weigh.

Even driving it unloaded, it got to about 1,200 today when I stepped on it, but then dropped as I took foot off gas.

It is more the limitation of getting to 1,300 on a mountain pass, even when not hard on it and the fan clutch running the entire time, sounding like a frieght train and dragging down my gas mileage.

 

To repeat a question, what is your coolant temp?

 

Sorry, was in a hurry earlier packing for another long drive. My coolant temp on the dash did not budge the entire time. My tranny temp gauge was not hooked up properly so I am not sure how hot that was.

 

I have watched my coolant go from 185 to 230 with the stock guage not moving from the center.

In a hard pull 1300 is ok, You need to look for a turbo back exhaust, that will help allot with the EGT temps.

10 mpg sounds LOW, I get about 15 with that load,

 

Yeah, 10 mpg does sound low, but for some reason my camper pulls heavy, it is a bumper pull so I am thinking part of it is wind resistance. I pulled my brother's 6,000 tractor on a flat bed and had no problems.

Either way, my EGTs are running about 1,000 degrees at 75 mph UNLOADED, it gets up to 1,200 on the mountain pass, and one short push at 75 going west up lookout pass, it hit 1,300, and yes it was unloaded. To me, that all seems high. I can get it to 1,200 just getting on the freeway unloaded. Does that seem normal for a bone stock truck?

I can do a 4 inch turbo back for around 300, but have read about just deleting the cat and the muffler. Being that I plan on keeping it basically stock, will the full pipe run cooler than just deleting the cat and muffler?

But the bigger question, is that too hot regardless, so there is other problems going on?

Please let me know your thoughts, again...

 

I have watched my coolant go from 185 to 230 with the stock guage not moving from the center.

In a hard pull 1300 is ok, You need to look for a turbo back exhaust, that will help allot with the EGT temps.

10 mpg sounds LOW, I get about 15 with that load,
15 mpg? in the hills? with 7-8000lbs? Are you running a tuner while towing??

 

The mileage seems a little low and to me the EGT seems a little high. But the EGT thing could be probe placement as well. My EGT's are a little lower with similar loads. I'm getting around 1100 while pinned down at 28 lbs boost climbing a mountain pass. But like I said, probe placement might be that difference.
What is your coolant fan doing? Is it coming on and staying on? I'd also get an after market guage on that coolant temp and find out what's really going on.

 

Yeah, when I did the gauges, I did not know the water temp was a dummy gauge too, so I just did tranny and EGT. And yeah, it could be probe placement. Mine is drivers side close to the cab on the bottom.

When driving unloaded in 90 degrees outside temp, then is a quieter fan running quite often, not sure if that is coolant fan or a fan from the new oil cooler kit (haven't research what the difference is between the kit and the oil cooler). But when towing, the fan clutch that sounds like a freight train comes on just as I start up the pass and runs for most of it. Since I got the EGR and oil coolers done, it does not come on during flat driving anymore.

Am thinking of taking back to dealer to have them check the oil cooler install.

One other thing to add, it appears when towing that it won't pull any harder at 1,300 degrees. In other words, no matter how hard I mash the pedal, it will not pull any more when my gauge hits 1.3k. So in the morning when it is cool, I can pull the same pass harder as my EGTs are a little lower.

 

I did a 3.5" downpipe to a 4" pipe with a 4" cat (from a Cummins) and Magnaflow's muffler and I haven't seen my EGT's go over 1080 degrees yet.....and that includes a 31' bumper-pull toy hauler that was weighing almost 11k pounds towing through the Sierras. As soon as my truck downshifts and the turbo really kicks in, then my EGT's are only in the high 900's. I guess the Exhaust upgrade was really worth it. My truck is not running any programs right now.

Don't feel bad, my truck sounds to be identical to yours and I get 10mpg with this toy hauler too. When I pull my 7k lb 30' snowmobile trailer at 75mph, I do get about 11mpg when I'm running a tune. All trucks are different in the mpg arena.