donkypuncha

When i drive like a granny the turbos whine normal but sometimes when i give it gas from a stop when it shifts from third to 4th the turbo will be boosting then give out for a split sec the boost up agian and some times when in 5th giving steady throttle with boost it randomly cuts out like a presure valve opens off and on . anyone notice this issue.

domboost

can't say i have. But please put some punctuation in posts. I had to read this 4 times.

Joewee3.5

Maybe it's the truck shifting that's making the turbos sound change. Unless you are wide open in 5th and the whistle is changing, then I'd say you're at the rev limit.

lumbermill

This has been discussed quite a bit around here. Lot's of folks driving around with a Scan Gauge or other monitoring device. From what I've read on here the boost will gradually drop as you are accelerating until a shift point at which the boost is vented to the atmosphere. After the shift the boost will begin to build again.

ohandtrytousesomepunctuationandpropersentencestruc tueuwillgetalotlessh8inandmooranswerstour?s

Leadsled124

The motor gets a little louder as you rev up and drowns out the turbos. Also yes the psi drps 1-2 lbs but that you cant hear a difference. The valve dump you are hearing is the wastegate/BPV releasing the pressure when you let off and recirculating it
The 5th gear random boost is just the load your putting on the truck . When you load the turbos they spool up. Lug it up a hill and you will hear it. If you had a boost gauge which should have come stock, you could watch the characteristics of what the gauge is doing under different conditions and it would all make sense

donkypuncha

when it boost and cuts off you can fell the diff in power. Its like it starts lagging for a split second then comes back.

ajkelly

I also noticed this valve dump noise you speak of. Although it took 8,000 miles for the noise to appear. I hear it at most shifts and when letting off the throttle. Just seems strange that it was not there from the start. The Ford garage is checking it out next week for me. They mention one other truck came in with a similar claim and corporate Ford said it was a normal noise after the turbos got broke in.

Leadsled124

For some odd reason i noticed a slight increased turbo noise after break in. Which is strange since ive never had to break a turbo in before. My only guess is ford is telling the truth that they are holding back on the tuning until a certain milage or engine running hours is reached. Maby they hold a few lbs of boost on the table until then.