Need Help:Limited power underload, any ideas?
 

I have a 2003 6.0 and recently experiancing limited power while towing a load. Things I notice while towing: sound of maybe the turbo or flood gate or something almost constaintly cycling, On hills, inclines an odd smell of anti freeze, on one of the mountain inclines my maximum speed by the top of the hill was only 35mph it never seemed to shift down and just slowly went slower. It never did this prior to installing new larger tires about 6months ago, the tires are not much larger 33" dia., but could that affect the programing and not allow things operate properly? Any Ideas Would Greatly Be Appreciated!!!

Any engine mods, how many miles, how often is the truck used and what for? Need more info. Any check engine lights? See if you can pull codes. Antifreeze smell usually is ruptured EGR cooler, headgaskets or might just be a faulty coolant reservoir cap.

You spelled cummins wrong!:moon:

03 limited towing power
 

Mdub707, No Mods, 76,000 miles, Daily driving with occational pulling of 12,000lb loads, havent pulled any codes, no engine light, and yes it might just be the reservoir cap it looks as though fluid has been coming out of there. The temp gauge never goes past half way? What ya think about the larger tires, could that affect trany shifting, and the cycling of the noise I hear?

Thanks'

MFCummings

Tires wouldn't do anything like that. I have two buddies running 37's on stock gearing with no issues.

That "cycling noise" you're hearing is probably coolant pushing out of the reservoir, sounds like a tea kettle right? It MIGHT be the cap but is probably EGR cooler or more than likely headgaskets. You wouldn't get codes or anything with this, I didn't either. From the sounds of it, it's headgaskets and it's severe, especially if you're losing that much speed. Be careful because it can hydrolock if it's that bad.