Traveling Duramax
04-10-2005, 09:02 PM
2003 Chev 2500HD Duramax/Allison, 31,000 miles. Always serviced ahead of time by dealer.
This past week while towing about 12k fifth wheel trailer, I initially noticed a power loss when the truck slowed and shifted to third gear. Pushing the accelerator further yielded no response. On other grades when shifting only from fifth to fourth, no noticeable power loss was encountered.
Sometime later the engine check light came on steady with the truck losing power down to about 10 mph. After about ten minutes I was able to pull off into a truck stop and check various things -- fluid levels, fuel cap, fuel tank vent hose, etc. All appeared to be in order, but the light stayed on.
After letting the truck sit for several minutes, when I started it, the check engine light was off.
However, on my way home (about three hours of driving) the truck would from time to time lose power with my speed slowing from about 55 or 60 mph down to about 45 mph on moderate grades. Once on a rather steep hill the truck shifted to third and dropped the speed to about 30 or 35 mph. In the past, on these same hills the truck never shifted below fourth and would maintain speed.
The engine and trans are stock OEM. The fuel tank is a Transfer Flow 45 gal replacement for the OEM 26 gal, but has been in the truck since new.
The tires are slightly oversize at 265/75x16 but have been on the truck for over 20k miles with no problems earlier noted (tire diameter is less than an inch over OEM).
Anytime there was the power loss condition, additional room was available to push the accelerator down, but it did not cause any change to the engine speed.
One other factor...weather was 60s and dry. Road was also dry. Fuel for the 8,000 mile trip that I was on came from Flying J truck stops. Earlier in the trip the truck pulled the fifth wheel over the western mountains with ease.
Any help would be greatly appreciated.
This past week while towing about 12k fifth wheel trailer, I initially noticed a power loss when the truck slowed and shifted to third gear. Pushing the accelerator further yielded no response. On other grades when shifting only from fifth to fourth, no noticeable power loss was encountered.
Sometime later the engine check light came on steady with the truck losing power down to about 10 mph. After about ten minutes I was able to pull off into a truck stop and check various things -- fluid levels, fuel cap, fuel tank vent hose, etc. All appeared to be in order, but the light stayed on.
After letting the truck sit for several minutes, when I started it, the check engine light was off.
However, on my way home (about three hours of driving) the truck would from time to time lose power with my speed slowing from about 55 or 60 mph down to about 45 mph on moderate grades. Once on a rather steep hill the truck shifted to third and dropped the speed to about 30 or 35 mph. In the past, on these same hills the truck never shifted below fourth and would maintain speed.
The engine and trans are stock OEM. The fuel tank is a Transfer Flow 45 gal replacement for the OEM 26 gal, but has been in the truck since new.
The tires are slightly oversize at 265/75x16 but have been on the truck for over 20k miles with no problems earlier noted (tire diameter is less than an inch over OEM).
Anytime there was the power loss condition, additional room was available to push the accelerator down, but it did not cause any change to the engine speed.
One other factor...weather was 60s and dry. Road was also dry. Fuel for the 8,000 mile trip that I was on came from Flying J truck stops. Earlier in the trip the truck pulled the fifth wheel over the western mountains with ease.
Any help would be greatly appreciated.