jf109

First and foremost, happy Memorial Day and a hearty hello to everyone on the forums! Long time lurker, first timer poster. I've searched the forum to death looking for something that sounds like what I have going on and have yet to have any luck. I have a 2011 FX4 with the 2011-2014 F150 EcoBoost S3M Phase 2 Performance Pack (AFE Intake, AFE Cat-back 4", Charge pipe and SCT LiveWire with 5-Star tunes) When driving with the stock BOVs I had a pretty unhappy sound that I can most closely relate to the sound of tire squeal when under heavy boost and the stock BOVs should be activating (sudden drop in throttle). I swapped out the stock BOVs this past weekend for some Turbosmart Kompact BOVs in the hopes that this might fix the issue. The noise has changed but now I am getting a balloon leaking sound right after the BOV activates. I have reconfirmed that all vacuum lines are where they should be and everything SEEMS tightened up. I have gone thru 3 tunes as well as back to the stock tune with no difference. The sound seems to happen much much more at low RPM / low boost. If I am at WOT then I cannot hear it. I was thinking it might be the wastegate solenoids as many astute individuals on this forum have already pinpointed them as a point of failure. Could it be that the solenoids are activating at too low boost and dumping when there isn't enough pressure to dump? Here is a link to a youtube video detailing the sound.

TJPlatinumEB

1. Wastegates don't make noise. They are just an actuator that is pulled open by boost and shut while under vaccuum. The actual wastegate itself is physically inside the turbo. You won't ever hear a wastegate make noise.

2. If you had a wastegate failing and wouldn't close, you'd never build boost. If it was failed open, you would never stop building boost. You would have engine lights going off all over the place if either of these things were the issue.

3. Your truck appears to be making two noises when letting off the gas. Which one are you talking about? The first or second? The initial rush of air or the whistle? Have you sent this vid or talked to your tuner about any of this and see what they say or recommend? I know you tried multiple tunes, but what have they said they think it is? Have they heard the noise?

If you aren't getting codes and the truck runs good, then I wouldn't be too terribly worried. Yes it is an odd sound, but it could be something as simple as a crack in a vaccuum line or something like that.

jf109

Thanks for the reply TJ. I shot an email off to the tuner yesterday, no reply yet. The second noise (the weird bark, whistle, squeal, haunted truck sound) is the odd noise I'm referring to. I think you are right about the vacuum line, I had heard that the solenoids controlling the BOV had a tendency to leak and could be causing the issue (the ones I incorrectly referred to as wastegate solenoids) It sounds to me like a leak. Everything runs just fine and the truck builds boost with no problem, so I have that going for me.