pulling issues & temps...

[dakotakid]

We just got back from a 3000 mile trip - ND, MT, & ID. I pulled a 40 foot Cross Terrain 5th wheel with a jet ski in tow behind that. Total length was 73 feet. It pulled like a dream - WAY better than the travel trailer we had last year! Fuel mileage went from a worst of 6.8 to a best of 9.3, with low 8's being the average. I ran the Edge on levels from 0 to 3, with most of the time spent in 1 or 2. EGT's were in the 1200's most of the time, 1300's on the hills, and I saw it hit 1400 twice for a few seconds. My biggest issue was water temps. As soon as the truck started working for a sustained period my water temps started climbing into the 220-235 range. It didn't matter what power level I was at - I could make it heat on any level. My worst hill was climbing out of Boise on Hwy 55 - thermometer said 102, water was 240, 1st gear, 18 mph, can't remember where the egt's were when I got to the top. I did much better on the return trip - I knew where the biggest hills were and approached them a little differently. Question is - how do you keep them from heating so easily? Last year when the truck was stock and I pulled a much smaller trailer I had the same issue - water temps on the big hills.
Otherwise, the truck was great! I really liked having the Edge monitor to keep an eye on the vitals. Water temp on the Edge usually read about 220 when the dash showed just under 210.
Anybody else have water temp issues??

Pat

[OC_DMAX]

Which one of the three DMAX's in your signature were you pulling with? (If it is the 2004, is it an LLY engined truck?)

There have been some issues with the LLY engines overheating. Depending on which poll you read, upwards of 33% of the LLY trucks exhibit this problem. I have never heard of an LB7 engine having this issue.

[dakotakid]

Sorry - forgot to include that. I was using the 2004 with the LLY engine. Last year when I pulled a smaller camper and the truck was fairly new and stock, I had some heating problems on a hot day. Since then I have added several mods (see sign)and upgraded to a much larger camper. I did have some heating issues pulling the smaller camper a few years ago with the 2002 LB7 engine - if I recall right I was using the Predator tuner at the 40hp setting and I would start heating on the big climbs...

Pat

[markrinker]

I'd get to bottom of those heating issues pronto, or pull less. Heat kills the best of engines.

[OC_DMAX]

Pat,

At www.yahoo.com, (http://www.yahoo.com,) use the search funtion and type in "LLY Overheating", "LLY Over heat solutions", and various combinations, etc. You will stumble on a number of topics in different forums where people are discussing this issue. Some forums are more aggessive than others at attempting to get at a solution to this problem that is causing havoc among a small subset of LLY owners.

Also, if you have a chance, go to your dealer and look at a 2006 DMAX. Look under the hood at the radiator, radiator shroud, engine air cleaner, engin air intake and location of transmission cooler (among other things). GM realized they have a problem and made some significant changes.

Alan