trouble towing above 55

[fordboy]

I have a 97 f350 7.3 five speed I bought a few months back. It is 100% stock all original as can be with 290000 miles. I have towed my boat with it on several occasions which weighs in at about 5000 pounds with no issues, can go 70 all day if wanted. I hooked my 5ver(10000 pounds) up to it today for the first time and towed it about 3 miles to just make sure everything was good. I seemed to be having trouble getting above 55. I will try again in the next day or so cause I just towed it around the block which is 1 mile sections each time, so not really a lot of room to roll it up past 55 before having to slow again. If I do find its having trouble with getting it to continue to accelerate after 55 what do you guys think I need to be looking at? I have put 4000 miles on it so far and dont seem to notice any issues with the truck and this is probaly my 4th or 5th 7.3, but all the others were superdutys.

[diesel_brad]

Sounds like a tired stock OBS. Nothing really wrong

[pa-powerstroke]

With that many miles probably just a lot of blowby

[fordboy]

So what are you guys telling me I need to rebuild? It doesent seem to have excessive blow by from the tests I read to try on here but I guess I will recheck it. runs great other wise.

[diesel_brad]

I would 1st do complete service on the whole truck, engine to axles, filters and fluids.

If blowby is not a problem, I would be looking at injectors. These injectors are typically for for 150-200k. After that they just got sloppy and inefficient.

You could also look at power adders(chip, exhaust, intake)

[fordboy]

ok whats a good wayto check the injectors? Do you think a chip and intake/exhaust would help if thee is other issues or will I be adding to my truobles?

[diesel_brad]

You have to pull the injectors and have the flow tested

[pontiacross]

make sure you dont have any exhaust leaks between the heads and the turbo as well, it could just be a boost issue

[fordboy]

I think I may have an exhaust leak as when you have the windows down and you are driving down the road you get a strong exhaust smell in the cab.

[fordboy]

tips on where I should be looking for the exhaust leaks at? Also is there a concrete way to verify what I have if any for low by to verify this is not the trouble. Hard to believe it would be for as well as the truck runs, and it has no issue at all with pulling the load up to 55. Still have to hook it back up again though.