I love my '06 F350 4x4 Crew Cab Harley Diesel. My first truck ever. Bought it to do mountains while pulling a toy hauler in mountains. Retired and ready to travel the country.

In the last 3 yrs., when towing about 10,000 lbs. up-hill in the Smokies on hot (85F+)days, I get this loud roar from under the hood and a loss of power to the extent that I have to use the slow truck lane at 30-40 miles per hour. Very embarrassing!!!
The truck also has problems shifting into the next gear up unless I ease up on the accelerator. The noise then eases a bit but still no more power. The turbo gauge and RPM gauge are not effected much by the roar and loss of power.

The truck is still under a Ford extended warranty so I have been to dealers in Michigan, North Carolina and Florida without success. They have replaced EGR valves, Speed sensor valve and other valves, as well as fuel filters, air filters, etc. I change transmission oil and coolant as well as oil and filter much sooner than recommended.

I'm afraid that too many dealership mechanics are just code readers and not diagnosticians. So is there some key to this problem?

 

Sounds like you're hearing the fan kick on... it's LOUD when it's locked up. How fast do you expect a stock truck to pull 10K up hill in the heat? Do you have any guages installed on it? Any mods?

Welcome to DB! We have a pretty healthy 6.0 section, lots of info for you down there.

 

 

Mechanically, this 2006 truck is completely stock so as not to mess with the extended, extended, soon-to-be-extended warranty until 2015. The price of peace of mind -2300 bucks- on or before December 28th.
Unless I can solve this issue, I'm forced to bite that expensive bullet.

Yes, I have the stock gauges. On a 95F hot day here in very flat southern Michigan, I loaded the Harleys and the beloved Valkyrie into the TailGator, put the Diesel "expert" at the dealership behind the wheel with his code reading gizmo plugged into the computer. To his surprise, the loud roar and all the symptoms appeared while pulling the load over an I-94 overpass. Not much of a hill!!! It startled Mr. Code-Reader and stumped the gizmo. His guess, flush the exterior bottom of the radiator of debris which may cause shifting problems. Even though the gauges showed normal transmission oil temp. That cost me another 285 bucks with no improvement.

Come on guys, give me some direction. I don't mind throwing a little more money at the problem, but I need to throw it in the right direction. It's driving this retired psychologist nuts!!!!

 

Welcome to the site

 

First off welcome to DB. Secondly on a hotter day the oxygen in the air is less dense which means you are not getting nearly the burn would be on a cooler day. The cooler you can keep the air the more efficiently your truck will run and burn the fuel. Thats why most people who tow run water meth, intercoolers, and air intakes to help get more air and cooler air into the cylinders. Towing in hot temps can play havoc on any truck

 

Thanks, guys, for the warm welcome. I'm surprised at the hot air affect on the power while towing. I'm wondering why the temp did not rob power during the first couple of years. What that means is the Rockies are out of the question. I might also post this problem on some RV sites.

There is a independent repair shop that has kind of a treadmill to run the truck with a simulated load (dyno or dymo). Is that something you guys have tried out? Keep in mind that the end of the extended warranty looms large.

 

to DB!

 

Anything thing that can be affecting it the the effect of the EGR Systems and CCV systems on the vehicle. You trucks Crankcase CVent System vents into the intake of the turbo which then leads to filling your Intercooler with air causing a restriction in the air system which in turn raises air intake temps and creates less power. Another reason may be the fact of all the oil from the CCV system combining with the EGR gasses casuing your intake runners to clog. Which can lead to the same issues and the restricted air system. Also does the truck seem to build boost like normal?

 

The boost needle on the gauge builds up to above the middle so nothing too unusual. Just the loud roar and not much action. As soon as you ease off the throttle, the truck shifts and the roar goes away. You gave me something to take to the code readers. Any other possibilities?