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Woo Hoo!! Truck Has A New Noise!!

Mad Maxx

Mad Maxx

See, what had happened was...
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Ok, haven't Driven the Truck for a Week, Hopped in Today and noticed a New Noise, I think it's coming from the Transmission.

Truck Drives perfectly fine around Town at Light Throttle, but when I Pulled Out in front of someone and had to give it some Pedal, there is a very weird Scraping Sound with a Slight Vibration. The Truck still Accelerates and Shifts Fine, but there there is this New Scraping Sound. Checked the Fluid, and there was a good amount of Tiny Air Bubbles on the Dip Stick (not sure if that means anything, but figured it's worth Mentioning), Fluid is still nice and Red, didn't Smell Burnt, Level was a lil Low so I Added some.

Could the Converter be Shot and what I'm Hearing / Feeling is it Slipping? I sure Hope that the GMAX6 & 1054 could Hold the Power I'm putting down, because I surely DO NOT Beat on my Truck at all...Hell, I barely even Drive the damn thing!

Any Ideas?
 
How hot was the trans. It needs to be right at the bottom of the hot hash marks at 160-180 trans temp.
 
The Allison's have been known to make some pretty crazy sounds when cold. I have been using my front grille cover lately now that the cold snaps are coming. It is the only way I can get the engine and the Allison warm and up to temperature.
 
Take a long highway ride and get the trans nice and warm. Then check the level.
 
Ok, some Interesting-ness Today.

Noise is still there.

Checked Engine Oil, it barely Registered on the Dipstick!! Got out my Drain Pan and pulled the Plug...def got about 10qts out, if not, pretty damn close. So I dunno what that's all about? Needless to say, I did a Full (early) Oil Change, just in case.

Pulled the Allison Spin-On, Fluid was still all good, light amount of "Dust" on the Filter Mag. Cleaned it all and put on a New Filter.

Drained Transfer Case, all good, Re-filled with 5w-30 through the Speed Sensor Hole.

Checked Rear Diff, just a lil bit of Metal "Fuzz" on the Dipstick Magnet.

Went for a Drive, Noise is still there...seems to be coming from the Firewall / Trans Tunnel Area now.

EGT's seem to be Low, and Boost is Low as well.

Come Home, Pop the Hood and Stand on the Nerf Bar and Nail the Throttle a few Times, and get a Puff of White-ish Smoke from the Rear-Middle of Engine, right in the Area of the Turbo. It came from Under the Cowl so I couldn't Pin-Point it, but tomorrow I guess I'll Pull the Turbo Heat Shield and see of I Blew another Hole in the Downpipe. The Matting on the Firewall looks Chewed Up pretty Good behind the Turbo as well, but I forget if it was already like that before.

Would a Hole in the Downpipe cause LOW EGT's and Low Boost?

Another way I can Describe the Sound is a Basic High CFM Air Leak or like the Engine has entirely WAY too much Timing Rattle.
 
Don't forget you have two exhaust pipes feeding the turbo - that's where I would look. Maybe the turbo controls are binding?
 
WarWagon said:
Don't forget you have two exhaust pipes feeding the turbo - that's where I would look. Maybe the turbo controls are binding?
Click to expand...

Checked the Up-Pipes as best as I could and they look good.

I was thinking maybe a Stuck Vane also, good thing you Reminded me.
 
I agree with Mike. Check the flange for proper tightness. If you installed an aftermarket exhaust system with either a turbo back or a downpipe back setup, it may be loose. I would like to think that if it was an issue with the turbo or a stuck vane, then you would be getting the CEL or throwing a code of some sort. Check for hidden DTC's. It could be something with your EGR bypass as well.
 
Pulled the Heat Shield on the Turbo and Looked / Poked / Felt around and can't see any Holes, Loose Clamps, Bolts, nothing.

Ok, so this is 100% Turbo Related.

I had my EFI Tune Set Up with an LB7 Idle, so this morning I Loaded in a Tune with a Stock Vane Profile, and as soon as I Turned the Key, there was an Interesting "Click" Sound from under the Hood. Started the Truck and the Hiss just doesn't Sound like it used to. I don't think it's as Loud as it was.

Give it a few Revs, everything was good so went for a Test Drive. I couldn't see exactly when it Starts, Boost wise, but the Noise comes in around 16-20psi and stays, then it'll go away.

Now at Idle, if I keep giving it some Revs, I get small Puffs of White Smoke in the Area behind the Turbo / by the Glow Plug Box. If I really Goose it at Idle, I'll get a Decent Puff of White Smoke.

So....

It is Vane Position Sensor Shot? Stuck Vanes? Bearings starting to go? Turbo Blown?

There is no CEL, didn't Scan for any Hidden Ones.

Can I Log / See Commanded Vane VS Actual Vane Position in an EFI Log?
 
So just did some Searching around on the Net, and while it isn't as common on our Trucks as it is on the Powerstroke, it DOES happen.

Alot of people say to just go out and Beat the Snot out of it and that should free the Vanes up if they are stuck. They say you can't hurt anything because everything is Governed. Does that sound right?
 
Well you could try that... Of course I didn't say it was a good idea...:dunno:
But it IS something I've been known to do. If something acts like it wants to break I give it an opportunity to prove it. :D
 
I'm gonna pull the Vane Sensor and Vane Solenoid tomorrow and see if something is Obvious. I'll Clean them up then go an give it Hell.
 
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