pfbz

2011 F150. Stock except for canned SCT tune. ,

I get an occasional boost 'flutter'. Happens most frequently when:

1) On an incline
2) Moderate throttle pressure, enough to kick up the boost but not enough to kick down the transmission.
3) Often at high altitude.

Boost starts to dump/build/dump/build over a 3-5 psi range very rapidly with accompanying venting sound. I finally caught a bit of it on video, below. Sometimes the fluctuations are a bit bigger than shown. Once it starts oscillating it seems to continue unless I either back out of the throttle or put it down enough to kick down to a lower gear.It's not specifically related to boost pressure...

Problem occurs with stock tune as well, just harder to reproduce. Fresh-ish plugs & plug tubes.

Usually the truck will make/hold the boost levels shown without the flutter. I've been reading about potential problems with waste-gates (2011 manual waste-gate actuators), possibly a bov issue (again, 2011, so dual turbo mounted bov's), boost leaks, solenoid valves, etc. but nothing seems obvious with the intermittent nature of the problem.

Any thoughts?

Further troubleshooting suggestions?

Order of priority if I'm going to start throwing parts at it?

kruman

My 2012 does the exact same as yours, particularly when it's cold outside. I'm not sure of the exact cause yet. I have read a lot and have about the same list for troubleshooting you do.

cougatCHASER

Have you ever found a solution after 6 years?



I have a 2011 f150 EB that does the EXACT same thing with no luck. I can hear the driver side turbo (sounds like the waste gate opening) but it’s more that strange flutter.



It does it under moderate acceleration, as if I’m forcing the truck to do something it doesn’t want to do until I give her all the beans.



I have NO vacuum leaks



I monitored the boost gauge with my OBII Scan tool that links to my phone.

While under moderate acceleration (1,800-2,500 RPM’s) in 6th gear, I can see the RPM’s bounce between those parameters.

- while monitoring boost

Results: boost builds between 6-8 psi, I hear the flutter/surge and the boost drops to 6 psi. Still holding the accelerator in the same position, boost builds to 8 psi and “flutters/surges” back to 6 psi. (it’ll do that indefinitely until I press the accelerator to trigger a down shift - will still surge but less noticeable



I’ve done the below;



- drilled 1/16 inch weep hole.

Results: all the condensation that built up in the intercooler, puked out (approximately 1-2 oz) I didn’t measure it



- put both BOV’s under a vacuum

Result: both BOV’s hold a vacuum (up to 25 psi)
while vacuum testing BOV’s, I sprayed some penetrating oil on the arm that actuates the BOV



- put all three bypass solenoids (Part #: BL3Z 9K378 A) under vacuum

Result: all three held vacuum


- additionally, put the bypass solenoids on a 9v battery while under vacuum and not under vacuum

Results: no issues either way. Audibly heard the solenoid opening and closing as intended.



- pulled throttle body

results: not noticeably dirty - still replaced since I had the TB off. (I’m an amateur and I was at the end of my rope and limited options/knowledge)



- installed Mishimoto catch cans for the excessive blow by

Results: highly recommend because there is so much crap that would normally go into directly into the intake
(trying to extend spark plug and intake valve lifespan)



Replaced turbo coolant o-ring and aluminum bolt (Driver side/same turbo where “flutter/surge” is heard) (Part #: BL3Z 6A968 C)

Results: no longer leaking, still surging

(Hoping that was causing the turbo to go above operating temps and not build boost safely, or a vacuum leak) (more so wishful thinking, I knew it wouldn’t fix the issue but still needed to stop the coolant leak)



Additional:

no white, blue or any shade of smoke coming from exhaust

Transmission shift points are fine - trans fluid is where it needs to be.

hope that make sense. Like I said, I’m an amateur and don’t know what I’m doing. If I used the incorrect terminology, please feel free to correct me. Tried my best not to throw parts at it since I’ve been down that road before. Any ideas/suggestions/solutions are greatly appreciated.

my next step is to sell it, buy a naturally aspirated, pre-OBI or OBII, carbureted, pushrod engine because this is too much. Apparently, I have 360 HP but I wouldn’t know because of this lol

also, pardon the typos, autocorrect took over