filter minder bottomed out... noise?

[Forrest Nearing]

coming home today I heard a noise I've never heard before... Only happened at WOT in OD above 3000rpm



couldn't really repeat it in 4th, but it certainly didn't sound transmission or speed related.



sounded turbo related... kinda/sorta like surge, but not so much "woof woof" as the turbo whistle kinda warbling slightly. Noticed I'm down maybe 1-2lbs at WOT. Everything else seemed fine. Thought maybe a boost leak that was only exposing at full song? (didn't make sense as it didn't do it in lower gears) Then I thought, well, I guess I found the lifespan of the sps62... I guess ~50k miles of 50-55psi is a pretty good run! but, again, it sounded fine otherwise... no shreeking like the wheel was rubbing, no woof/woof of surge (other than the occasional snap throttle release when jumping out to pass and seeing a car coming! LOL)



now, I've been up against a wall today w/ work running all over hell's half acre, and I've been beating on the ol' girl trying to shave time



earlier today we were flying up and down some gravel roads, and I often drive/work in dusty conditions.



I eye the filter minder every time I check the oil, and it hadn't pulled in despite the outerwear being fairly dirty/dusty.



pulled in and left her running, popped the hood and looked/listened for anything while I let the EGT's cool down. nothing looked out of place, etc.



saw the filter minder bottomed out and reset it and killed the truck.



pulled the little yellow cap out and there's a little white plastic valve/orifice that looks like it could oscillate if it was bouncing against the spring or if it was pulling so hard some air could sneak past the yellow cap.



the AFE race filter is drying right now (didn't look THAT bad, but the pre-filter was NASTY!)



just curious if anyone has ever run into a sound like that and traced it to the filter minder



thanks!



oh yeah, the shaft play on the sps62 feels like it did when I first pulled it out of the box Oo. Oo. I'd like to thank Industrial Injection for building a hell of a turbo and Shell Oil for their fine Rotella Synthetic

 

[JDiepstra]

I am not sure if you mentioned this but in different wording than my simple mind uses but I get a bit of a turbo "woof" on occassion when I let off the throttle too quickly at high boost levels. I think it is because there is less pressure on the "in" side of the turbo than the "out" side of the turbo and the air is trying to get back through the turbo. This only happens when I let off quickly and as I read your post again, that doesn't sound like the problem.

 

[Forrest Nearing]

this was only happening at WOT in high gear above 3000RPM. boost was down from 49psi to 47psi

 

[AllianceDiesel]

yep thats whats happening, we call it turbo bark, its when there is so much air trying to get forced into the engine and then there isn't a need for that air and it has to escape somewhere, so it goes back out, have seen it on a locomotive blow up a turbo.

 

[KAlder]

:I think Forrest probably knows what turbo bark is

 

[Forrest Nearing]

this is not turbo bark... I have been running this combo for over 30k miles



this is a brand new noise today