Intermittent boost loss

[Heavyhaulmark]

Hello and good morning! Newbie here. I'm having an intermittent boost problem. A little background, the truck is a 2013 factory 4 axle 367 pete with a 600 hp isx 15.
Back in the summer I replaced all the usual sensors for carbon build up.
Recently I have replaced the turbo(complete with new actuator, turbo was purchased from HD Turbo) CAC, boots and clamps. While the turbo was off, I had the complete after treatment system removed disasembled cleaned and reinstalled.
I haul heavy, 220 - 230k loaded, 90k empty so I'm heavy all the time.
After doing the turbo I ran several loads in the 220k weight range when suddenly it developed this boost loss issue. I first noticed it on flat ground. We were fighting a bit of wind so the turbo was spooling about 32ish lbs when POOF down to 10lbs of boost.... no codes, no warnings, all other gauges normal. Boost pressure returns after about 30-60 seconds. It began repeating this randomly. My first thought was the imap sensor. Upon inspection, IT WAS PACKED with carbon. I cleaned it up and the problem seemed to go away albeit temporarily. Now it's back. Looked at the imap again and it's not bad, light carbon only. I'm going to change it again anyway, but is there anything else any of you guys can think of to cause this? Tia!

[tree98]

You say you purchased the turbo from HD turbo. Is it a holset vgt or something else?

[Heavyhaulmark]

Holset vgt reman. They boast a better reman process than factory. However I'm still getting a lot of whine out of the turbo, even at idle.

[Waterloo]

Did it whine when you installed it?

[Heavyhaulmark]

This engine has whined since I bought it actually.. I thought replacing the CAC and turbo would cure all that but it hasn't.

[Heavyhaulmark]

When I purchased the truck it had 315k miles on it. It currently has 568k miles

[Waterloo]

If it is whining or whistling, there may be a loose clamp somewhere. Have you inspected the clamps on the actual turbo itself? And the the exhaust back pressure sensor, has that been replaced? I believe it is located on the top of the motor where the coolant thermostat is located. Tucked in behind there, like a 27 mm socket to remove if memory serves me right. I have a CM-871, so that sensor may have moved on your motor, but I think it is still there in roughly that location.

And that turbo, is it slobbering oil? And how about the actuator? New or old? And when the actuator was installed, was it calibrated with Insite?

[Waterloo]

Another thing too, have you ran an overhead? How does the cam look in there, and how often are you changing the oil. If your iMap sensor is clogging that quickly, may be time for some serious emissions service.

[Jose9640]

Any codes? Sounds like a VGT issue to me.