Power loss when towing uphill

[mannyg]

I have a 2005 F350 Turbo diesel with only 58,000 miles. When driving in town or uphill it runs great with avg turbo press between 20 -30 psi. I took my boat out the other day when I went up hill to the lake it ran great and actually eccelerated up hill.

On the way back I started to loose power. I went from 65mph to 40MPH with my rpm at 3,000 and turbo psi around 10 and the pedal was floored. A times I could hear a high whistl like noise. Trans and engine temp was normal. When I got to level road it accelerated and everything was normal again. This is the third time it has happened. did take it to ford dealer and they tested the turbo and replaced fuel filters and yet it did it again.

Anyoine have any idea what it could be??

Manny

[jimbo57]

I just had the same probelm with my 2006 F350 6.0. Towing a 7000 lb load from Vegas to San Diego. High temps in the desert so I didn't push it so much on the grades there. Kept it at 65 mph on flat and 55 on grades. Until the last grade in Temecula. Hit the grade doing 60. 1/4 mile into the grade I'm doing 40 with only 10 psi showing on the turbo and my foot almost to the floor. Engine temp and tranny temp still showing normal. After I got to the top, accel was good again and is fine now without the heavy load. What is the deal here?

[mannyg]

Exactly! The thing here is my RPM was 3,000 and doing 40mph. So I dont think its the turbo. Is there programming between the engine and Transmission?

[nylyon]

Do you know what your oil temperatures are? Is there any white residue on your degas bottle? You should see if there are any stored codes as well.

[mannyg]

my oil temp is normal. No eveidence of any overheating. There is however white residue on the degas bottle and I think it was also filled a little over the max level. I understand it should be at the Min level. there were no codes according to the dealer.
So what does this all mean, and how does this efeect the loss in power while towing uphill?

[nylyon]

Do you have a gauge to measure your oil temperature or are you assuming that because your dash gauge for water (coolant) temperatures read normal your oil temps must be okay? There are a lot of possibilities, but because I am having such problems with my oil cooler I suspect that your oil cooler is going bad. The oil temps are getting high enough for your truck to de-fuel which is your performance problem. Additionally, the lack of coolant flow through your EGR cooler is causing the coolant in the EGR cooler to flash boil and you hear that whistling sound, venting from the degas bottle.

Of course I suspect this only because I am going through the oil cooler replacement for the second time, and I am beginning to eat and sleep oil cooler problems and information so I am quite biased at the current time, added to that that I am not a tech, but it is completely reasonable that this is a possibility for you.

[mannyg]

No I have only water coolant temp. I assumed the oil and water should be relatively close in temp.

so the high oil temp would cause the lack of acceleration/power while towing? How does one check to see if it is indeed a bad oil cooler?

[charlanay]

Same thing happened to me, took it to the stealership and was told it was plugged oil cooler and EGR cooler. Changed out both in the same weekend, haven't pulled a load yet to see if it still does it. Did your fan come on and scream at you?

[mannyg]

was your trucks RPM around 3,000 at 40-45mph and pedal to the metal?

[surfdogskier]

Same thing happened to me pulling my toyhauler. Turned out to be my EGR cooler went bad which is often the result of a oil cooler going down. I put a EGR delete on mine but my oil temps were still way up, like 40-60 degrees over engine temp. Replaced my oil cooler with a bulletproof oil cooler condenser mount and now my oil end engine temps are almost identical.