Slooow 6.0

[Towin Slow]

Hello all..I am having some towing issues with my 6.0.
Truck is a 06 F 350 crew with 76,000 miles and no mods.
I tow a 11,000 pound 5th wheel RV.
The truck has a problem keeping speed up on any incline. I will have my foot to the metal with 27 psi on the boost gauge and continue to loose speed until I start going down hill. Some times a blower will come on when this happens. The dealer replaced the FICM on the 1st visit, head gaskets on the 2nd and the just replaced the oil cooler on the 3rd. I can understand replacing the FICM and gaskets but what would the oil cooler have to do with a loss of power. Has anyone had this problem with there 6.0. I thought mabe it was just me asking to much from the truck but when I was towing last week a F-250 gasser with the same weight class trailer blew right by me and my foot was to the floor.???? Thanks

[chuckles]

exhaust plugged up? have you checked codes? Is this manual or auto trans? What are your temps? Where are you location wise?

[Towin Slow]

Exhaust is working...The only code that showed was for the FICM...auto trans...all my temps were fine on factory gauges...I live in South Jersey with no hills to take the trailer and someone from the dealership to so that I can show them the problem.

[chuckles]

any smoke coming from tail pipe? possibly a driveline issue?

[Towin Slow]

No smoke and I don't feel the trans slipping.

[fordmugg]

leaky up pipes maybe

[VeeDubTDI]

The factory gauges are worthless unless the problem is really bad.

Has this always been a problem, or is it something new?

[Towin Slow]

This is the second season with the trailer and we started going up into Pennsyvania and New York this summer and thats when the problem started to show. When I tow along the east coast on flat roads there is no problems.

[VeeDubTDI]

Hmm... you really need some way to check all of the engine sensor readings. It could be defueling for some reason (oil temp too high, IAT too high, ...). Or perhaps your MAF sensor readings aren't quite what the PCM is expecting... not off enough to throw a code, but not right enough to produce good power.

We're really shooting in the dark without some data logs of what's going on with the engine while you're towing.

[Towin Slow]

So the oil cooler could be the problem? THey said when they checked the oil cooler there was a 25 deg. difference. I asked the about a flight recorder if this fix does not work to see what the truck was doing on the highway.