I'm on the verge of giving a dealer a "go" on a new '05 3500 SRW 4x4 DurAllison. I really like the truck, but I don't have forever to sift through threads to see if overheating is a design issue. Can someone more patient than I am please tell me if there is a concern/ problem with overheating? It doesn't really matter how much I personally have to tow, etc. I had an '01 7.3 Superduty that never even resembled getting hot, no matter what. I really would like to get this truck, but work two jobs and don't have time to play around with or figure out problems.
Great forum, btw!!
Thanks in advance.
Charley

please do a quick search or just sit down and scroll...I see at least 3 threads started about overheating.

welcome aboard

Also look at a post that has some details about the engine changes to the '06.

so far the edge juice has reported 203 degrees on two occasions (floored on #2 pulling a boat, 95* air temp), the allison has not gone over 190 degrees, i would say without a doubt this truck cools better than my 2003 dodge ram CTD. my personal experience.

was cooling mostly an issue on 2004.5s?

I have had both my 05's over 230 while towing within GM limits. I recently had 1 of them over 250, but that was under extreme conditions most people would never encounter. This is documented in the overheat thread.

HI Rick,
What are the details of your overheat? Truck speed, grade of hill, temp, humidity, altitude and load.

thanks,
jeff

I just towed 1300 miles with my new 05 towing 6000#'s at 80-85 in 90-100 heat with the A/C on. Truck is bone stock, so far, and trans never got above 190'ish with water temp right about 200. This was from Michigan to Texas including up long grades in Kentucky between Cincinatti and Louisville then on towards Bowling Green.

FYI, mileage at those speeds averaged 13.8. On the return trip, unloaded, but the same speeds, it averaged 16.6. I, too, was wondering what the heat and load would do to the temp gauges. Take care.

I'm on the verge of giving a dealer a "go" on a new '05 3500 SRW 4x4 DurAllison. I really like the truck, but I don't have forever to sift through threads to see if overheating is a design issue. Can someone more patient than I am please tell me if there is a concern/ problem with overheating? It doesn't really matter how much I personally have to tow, etc. I had an '01 7.3 Superduty that never even resembled getting hot, no matter what. I really would like to get this truck, but work two jobs and don't have time to play around with or figure out problems.
Great forum, btw!!
Thanks in advance.
Charley

I bought a new 3500 SRW duramax allison last week and read through all the overheating threads prior to buying. My background is I am a design engineer - physics and electrical engineering.

What I gleaned out of it was this...

1. If the truck is fully loaded (or nearly so) and the air density low (high altitude, high temp, low humidity) and a long steep grade is taken at high speed and full throttle - the truck will overheat.

2. 04.5 model trucks had a more serious issue but were made better by a reflash.

3. 05 trucks don't seem as susceptible to the issue.

4. Now that everyone here is constantly staring at their temp guage - some are thinking their trucks are running hot when they are perfectly within an acceptable operating envelope. 210 degrees is "nominal" - 230 is high - but not "overheated".

5. The 2001-2003 duramax engine (lb7) engine did not overheat if pushed to it's limits. The expectation by newer duramax owners (lly engine) is that the new truck will behave in the same manner. The duramax engine was redesigned to increase horsepower and torque the middle of '04 (hence the 04.5 designation). The newer engine will now overheat when pushed very, very hard under the right conditions (thin, hot, dry air that can't transfer heat quickly away from the radiator).


Bottom line for me was : Based on what I read - if I don't drive "aggressively" with a full load up high mountain passes - I won't have an issue with my '05.

- jeff

HI Rick,
What are the details of your overheat? Truck speed, grade of hill, temp, humidity, altitude and load.

thanks,
jeff

start here

http://dieselplace.com/forum/showthread.php?t=14625&page=149

No overheating problems with my '05 3500 LLY in Texas. It's been HOT (96-102 ambient temp) everyday since I got it 3 weeks ago. Always less than 210 (doesn't change) and the tranny temp 170-200. Towed a 10,000# travel trailer last weekend about 150 miles....same temp readings. The fan clutch seems to come in more than my '01 Yukon 2500, but never stays on more than a minute. Fact is, temp readings have been about the same as the '01. I'm gonna tow the TT to Ky for 3 weeks, so it'll get a good test. I've even idled it extensively in this heat with no problems.