One of the turbo's was squealing at about 99k, the dealer said they replace the turbo, now I have the following intermittent problem. The turbo/boost fails and the truck has no acceleration. You can see the boost gauge is at zero and the accelerator is mashed to the floor, I could be cruising at 80 on the freeway and the back off for a second then try and pass a car and the boost dies, nothing. I pump the accelerator, put it neutral and rev the engine repeatedly until the boost comes back. This happens in a thousand different scenarios, to many to explain. The dealer had engineers look at the truck and they said there was an excess of carbon build up in the turbo's, I don’t know what they did but they cleaned it up and it went away for about 10k miles, now it’s back and much worse. The truck now has 129k miles on it and I’m at a loss, obviously it’s out of warranty. Any ideas anyone?

 

sounds likethe electronics to the turbo's to me. Check the connection to the turbos and check your coolant level for it as well.

 

This could also be a fuel problem. Have your fuel filters been changed recently?

 

Yes I Have, we even make sure the water seperator is clean

 

It does in a way sound like something electronic, but nothing is repedative in the way it frees its self so its so hard to nail down

 

I guess my best advice for now is the check all the connections, ensuring good contact. Check the mechanicals to the turbo for proper operation.

 

I'm not trying to make you sound stupid, but did you change the filter at the separator, or did you just drain it?

 

Yes, the filter at the seperator has been changed, not a stupid question at all. I cant believe no one else has had anything like this happens, this sucks. I could walk out to the truck right now, start it up and low and high turbo's won't boost, how is that possible?????

 

What about turbo clamps? Are they tight?

 

I will have our mechanic check those, recently there has been an exhaust smell in the truck while at a stop

 

If you have an exhuast smell then there may also be other factors at play here.

 

Maybe your EGR valve is stuck open. Although that would probably be too simple of a fix.

 

I have a 2008 F-350 with kind of the same problem, if I'm driving at about a 100 km and floor the truck to pass a car i have no power about a 1/4 of boost, then if you let off and ease in to the peddle the boost comes up but slowly. if you pull over and shut the truck off and start it back up the power is back and works find till u drive at a 100 or slower for 10 or 15 min. some times if you hold the peddle to the floor till it govern out the power will come back. i have had it in to ford a few time and they can't find anything wrong with it.