Hi, I have a 2004 dually with a 6.0, with around 55,000 miles. The truck runs good but when I tow the race car trailer when I go up hills I get a loud noise,like the turbo is screaming and then when I go back to flat ground it takes a little while but it like spools down and runs normal till the next hill then the same thing. Any help would be appreciated. Ps, it seems like this happens after I have been running it a while. Thanks Jim

 

That is most likely the cooling fan.

You need to get gauges so you can determine the actual oil and coolant temps when that happens. A ScangaugeII is the cheapest way to go ($135 shipped when you join cleanmpg.com, $160 otherwise).

Are you losing coolant? Where do you maintain the coolant level in the degas bottle? have you inspected the coolant lately? Have you ever flushed your coolant?

 

It is the fan. We have an 06 and an 05 6.0 for work and towing our skidloaders they run quite often when we are towing up and down the hills. No big deal.

 

Sounds like the fan. I pull a 25' goosneck with up to 15K load. You will get used to hearing that fan kick in and out. As others have said, get a Scangauge-II. Not only will it tell you how your engine is performing, it will tell you when the fan is engaged.

 

cooling fan.....

 

Thanks for all the replys, I'm just glad it isn't anything with the turbo or anything else.

 

You still need to know the actual temps. You could have a plugged oil cooler, etc.

I guess you aren't concerned about coolant levels ...................

I know many people experience the high fan operation when towing, but it may not be completely normal - only the actual temps will verify that IMO.