Hoping someone with more experience knows what to look for here.

 

Last Feb I replaced my turbo, didn't get a chance to change the oil line so it had a slow leak, finally got around to replacing that, however to get the gasket remnants off, I attempted to rotate the turbo, should have just pulled it off instead. One of the bolts snapped. not a warranty-able item so I paid the shop I bought it from to fix it (drill/re-tap) During this process, I changed the exhaust manifold gaskets because one of them was leaking.

 

After all of this, I suddenly had a howl at 2-6psi... thought it may be the exhaust touching the frame, so when it was in for other service, I had them bump it over while they were under the truck. Didn't drive much since with all of the weather... but the other day I drove it, and not only do I have the same howl from 2-4psi, but at around 3 psi and 1400 RPM I get what sounds like when we were kids and put an index card in the spokes on our bicycles... 

 

Of course my exhaust has that Cummins fart sound of a straight pipe but never heard these howls and fan-ish sounds before getting those exhaust manifold gaskets done... are these just normal sounds that I'm only now hearing because of the increased flow?

  On 12/31/2022 at 7:19 PM, wh82 said:

Last Feb I replaced my turbo, didn't get a chance to change the oil line so it had a slow leak, finally got around to replacing that, however to get the gasket remnants off, I attempted to rotate the turbo, should have just pulled it off instead. One of the bolts snapped. not a warranty-able item so I paid the shop I bought it from to fix it (drill/re-tap) During this process, I changed the exhaust manifold gaskets because one of them was leaking.

When you say rotating the turbo, are you meaning that you loosened the bolts on the turbine side and rotated the bearing housing? You can clean the gasket off by not removing turbo or clocking it. It will take time and patience but it will work. Sure taking the turbo off is easier, depends on what your doing to justify the work, additional time, and gaskets/seals.

 

 

 When you replaced your drain line gasket, I assume that is the only line you replaced, did you oil the turbo from oil feed side before startup? Same applies if you replaced the oil feed line too. Every time I do a drain line or supply line I make it a habit to pre oil the turbo bearings or bad things can happen.

 

It could be that a manifold gasket is not properly centered and has an exhaust leak...

  On 12/31/2022 at 8:10 PM, Stanley said:

When you say rotating the turbo, are you meaning that you loosened the bolts on the turbine side and rotated the bearing housing?

Yes, couldn't really get to or see the gasket surface, thought this would be easiest to just 'clock' it at the time, I was wrong, turbo ended up coming off for repairs because the bolt snapped with no effort.

 

  On 12/31/2022 at 8:10 PM, Stanley said:

 When you replaced your drain line gasket, I assume that is the only line you replaced, did you oil the turbo from oil feed side before startup?

Yep, put oil in the top of it, spun the turbine a bit, did again a few times till the oil quit disappearing in the feed hole.

Have you checked for play in the shaft? Up/down & in/out

Any visible grooves in housings, fins look OK, etc.

I'm kinda leaning more towards a possible exhaust leak of some sort from from your card on a bicycle reference.  

Sounds are hard to describe and without hearing them, they can be perceived differently. 

Well I would pressurize the air system and look for leaks. Then I would inspect the turbo closely for any rubbing od parts. Like my HX35/40 I fried the bearings in the turbo the compressor wheel is rubbing the housing and does not spin freely. The noise could be a boost leak. 

 

Strange but true my 3/4 bushing unscrewed from the manifold and fell out and hung on the boost tubing. Even at zero boost, my EGTs bit higher 900 to 1,000°F but still drove no issues. The sound was very usual. So pressurized the air system you can here the leak easy being the air is rushing out then I saw my boost bushing hang on the tubing. Hua... there is my problem. Fixed.