Please help: Vibe breakthrough!

[DieselViking]

I think I made a breakthrough today diagnosing vibration/buzzing that I've got at idle. Been having problems with the constant vibing (my bedliner and dash buzz at idle) and also turbo fart while cold:

This is what I did on a hunch:

With key off, unplugged the little electrical connector on the upper right side of the exhaust side of my turbo housing (the VGT Control Valve)...

Started the truck- SMOOTH AS SILK! I havn't heard my exhaust have a deep rumble like that in ages! It sounded deep and CLEAN.

OMG! ALL VIBRATIONS GONE. GONE.

No wooshing in exhaust and no turbo whistle.

Raised the RPM's a bit in neutral and while powerbraking. No whistle.

NEXT:

Turned off engine. Read the codes: P0040 and P1000. Plugged little connector on turbo back in. Started truck:

Still SMOOTH, NO VIBES ANYMORE! HAHA...AND Turbo whistle.

Now the turbo would spool up to 10 psi while raising the revs in neutral...it would only push 3-7 before in neutral.

Took it for a drive down the street...WOW throttle response and quick spool up. Felt like a different truck...for a moment until...

The BAD part: Within 2 blocks of accelrating and shifting and coming to a stop...THE VIBES ARE BACK AT IDLE...

Also, the idle started jumping 50 rpm erratically, up and down, until I gave it throttle a few times, then it went back to normal.

WHAT IS HAPPENING? I think I made progress figuring out the problem? Is my turbo totally stuck? What's the deal.

Marc, other techs chime in? Thanks.

[DieselViking]

I did the same thing later today with the EBP sensor:

With ignition off, unplugged it...started it up...voila! Smooth idle and nice loud rumble to the exhaust, no more constant hissing like before...AND there seems to be A LOT more exhaust flow coming out of the tailpipe? This time though unlike with unplugging the EVRT solenoid, I actually got some turbo whistle while revving in neutral. ???

Turned it off, plugged the EBP sensor back in, started it...SAME symptoms back, dashboard humming, bedliner vibrating steady, idle blip, and hissing in the exhaust.

Maybe it's the EBP that's gone bad then?

I'm going to take it for a test drive with the EBP unplugged and see if there's a difference.

[mschn99]

your truck doesnt even referenc the EBP sensor anymore...so having that affect it makes no sence. The vibration you describe really cant be from the turbo either....i dont know if your just wanting to feel a difference or what, but unless the turbo is completely coming apart it wont cause a vibration at idle....

[DieselViking]

I'm taking it to the dealer this week, maybe they can figure it out. As of today the vibes got worse= louder. My driver side dash is vibrating/buzzing like crazy at idle. I can't explain the unplugging the sensors thing man, only that it made the truck quieter. Weird. I had a thought...could it be a plugged up catalytic converter? At idle maybe it has too much backpressure when combined w/ the turbo? When I unplugged the VGT solenoid, it would keep the vanes in the full open position, so maybe that's why it quieted down if it was the cat that's plugged up??? I cleaned my EBP sensor and the sensor tube yesterday, and now unplugging the sensor doesn't cause a change like it did before, except set a CEL. Weird too right? Cause like you said my truck is an '06 and isn't supposed to reference the EBP in the programming? Anyway, this week is dealer time. Thanks for your input as always. Adios.

[matty21]

Originally Posted by DieselViking

I'm taking it to the dealer this week, maybe they can figure it out. As of today the vibes got worse= louder. My driver side dash is vibrating/buzzing like crazy at idle. I can't explain the unplugging the sensors thing man, only that it made the truck quieter. Weird. I had a thought...could it be a plugged up catalytic converter? At idle maybe it has too much backpressure when combined w/ the turbo? When I unplugged the VGT solenoid, it would keep the vanes in the full open position, so maybe that's why it quieted down if it was the cat that's plugged up??? I cleaned my EBP sensor and the sensor tube yesterday, and now unplugging the sensor doesn't cause a change like it did before, except set a CEL. Weird too right? Cause like you said my truck is an '06 and isn't supposed to reference the EBP in the programming? Anyway, this week is dealer time. Thanks for your input as always. Adios.

I have the same vibrations as you. except this morning just to see. i started it up without being plugged in (-37 degreees celcious) and it started not badly but it ran so quiet i almost thought it was a gasser.till it warmed up. but while it was quiet it was also very smooth, with no vibrations. lemme know if you get the cure mabey i'l try.

[DieselViking]

Took it to the dealer. They wouldn't run the tests I asked for (cylinder contribution, egr, vgt)...tech said to me he won't test anything under warranty unless a check engine light is on...what a great dealer eh??? Claimed it was my short exhaust that was the problem and I tried to explain to him that the problem started already before my exhaust system. Go figure they jump for the 'non factory' thing right away. Anyway, he reflashed with the latest update and said he hoped it would help and said come in when the check engine light comes on. !!! Maybe they hope my warranty runs out before I have a problem? Haha. Anyway, I took it home and decided to try one last thing...I removed the exhaust and Cat completely. Just the downpipe now. Seemed to help. Loud as all hell now and sounds like a squadron of F-16's but the dash seems to have quieted down some and the idle seems better I guess. Maybe my cat was plugged up? Might just leave it this way. I'm gonna try some stiffer rubber hangers and weld up my joints on the exhaust and see if I get a difference.

[kinghawg98]

maybe its just so loud now you cant notice it....

[DieselViking]