2012 F350 Ambulance - Loses Power

[brianp87]

6.7L Ambulance 72,000 miles
So we get this thing in and it loses power every time it goes up a big grade. Has to be a large hill but happens 100% of the time. So we get it in drive it quite a distance 25+ miles to closest big grade and we can duplicate it. We find it loses boost. Problem only happens like this no other times not even a short grade. No cel or any pending faults stored. So we record data every time and try multiple times. Anyone have any guesses on what we found? It took us quite a while to figure this thing out. The only background beside maintenance this vehicle has had was exhaust temp sensors at 40k, turbo for a broken fin at 56k, water pump and rear radiator for overheating(it overheated big time) at 69k, leaking vacuum pump for oil leak at 69k. Maintenance was done often and up to date. Btw we found issue and is fixed but it took some time.....

[Jeff @ Able Auto]

My guess is a waste gate sticking open. Whats the prize?

[brianp87]

The waste gate on this is part of the turbo. I would have probally guessed that also. Im not sure we even got a prize for fixing it.

[steven kiser]

Sorry for the late jump in here, had a bit of a bug that laid me flat for a few days. There is and issue with a strain on the turbo because of a programming issue. There is a recall od trucks produced at the Kentucky plant. If this doesn't apply then I would agree with the Turbo replacement. From what I've read it's not uncommon. There have been instances where a partially clogged particulate filter will cause an issue like this because it can stop the turbo from spooling up properly. If the filter is the culprit carefully inspect the blades of the turbo. I read a few articles saying that they will crack under strain conditions. A quick suggestion here. If it were in my shop the first thing I would have done was call the dealer and have them run the vin for any warranty coverage or applicable recalls. Ford at one time covered all their dsl's for 100k no time limit. Don't know if this still exists but would hate to find out it was after the fact. Good luck.

[brianp87]

We fixed the vehicle it was time consuming to find the issue. The turbo we did a while back had a broken blade. Since I haven't gotten a lot of hits ill let you all know what it was so hopefully if you run into it it will save you some time. The oil cooler coolant passages were plugged. The engine oil temp was getting hotter then the coolant temp not a lot but enough to shut the turbo down under heavy load and not enough for a fault code. I think when the vehicle overheated in the past it burnt the silicant in the coolant causing the restriction.