Hey guys,
Last night I headed home from a buddies house and the turbo (hx35) started making noise whenever I got above 15ish psi. It wasn’t gradual, truck was perfect when I got out and made noise when I got back in. I’ve never heard an exhaust leak on a Cummins or any turbo vehicle but it’s almost like the turbo itself is leaking. At first I thought it was something hitting the turbine or compressor at low rpm but when you get the boost up it sounds more like a leak. Looking around I see no soot on anything under the hood. However, I’m still able to build 36psi which is the max I could before. No extra lag or smoke, no loss in performance that I’d expect from a leak. The turbo has almost no play, only a tiny bit of lateral play when it’s hot. None when cold. The sound is like a ticking flutter that varies with turbo speed but doesn’t happen in single digit boost. I ran the truck this morning cold and didn’t hear it at first but as the turbo got warm it certainly is still happening. I then tried taking the air filter off to get more sound and I don’t think I heard it but the turbo was so loud like that I’m not sure if it’s just overpowering the sound I’m looking for. The turbo spins freely by hand, no noise hot or cold. 
 I tried setting the air filter on some foam thinking maybe the cage was rattling and that didn’t do anything.

 

Heres some videos, I’m not sure you’ll be able to hear it but worth a shot. https://imgur.com/gallery/yedFsLT

 

Thanks, you guys are always helpful and cool 

Could be the compressor housing seal. 

1 hour ago, Threadzy said:

Could be the compressor housing seal. 

What are the usual symptoms of this seal failing? 

Edited September 10, 20204 yr by Reaper22

It’s just a guess from what you’re describing. No soot tells me it’s not on the exhaust side of the turbo. The only other side is the compressor housing. 

1 hour ago, Threadzy said:

It’s just a guess from what you’re describing. No soot tells me it’s not on the exhaust side of the turbo. The only other side is the compressor housing. 

Would I be able to inspect this seal by taking off the compressor housing? 

3 hours ago, Reaper22 said:

 The sound is like a ticking flutter that varies with turbo speed but doesn’t happen in single digit boost. 

 

That sounds like the turbo to manifold gasket starting to go. Soot don't always show up right away, I would look real close at that. If it is on the bottom it would be hard to see. Check all bolts on the exhaust manifold, they like to fall out.

You can make a boost leak detector. Pressurize the compressor housing with an air compressor set at 20 psi. Get a spray bottle filled with soapy water and start spraying  around the turbo. Might as well check the entire system. 

OK so I checked all the manifold bolts nothing missing there. I decided to take the compressor housing off and see what’s up in there. On the inside of the housing there are several nicks in the casting, one of which is raised high enough that i believe would definitely hit the blades, the blades aren’t damaged but Some of the tips have bright spots like the blade had been rubbing on something recently. There is also a random scratching further inside the housing. More videos if you’d like to see for yourself. After I spin the shaft I check for play. If you turn on the sound it clunks pretty good.

 https://imgur.com/gallery/1RCqdRb
The turbo definitely has more play in it when I really yank on the shaft with some force. What do you guys think? Rebuild time? 
Recommendations for a cheap upgrade? 

Edited September 10, 20204 yr by Reaper22

With the engine is off there is no oil circulating and that can exaggerate the play somewhat. So before I would condemn the turbo do a pressure check on the system as advised above.

21 minutes ago, dripley said:

With the engine is off there is no oil circulating and that can exaggerate the play somewhat. So before I would condemn the turbo do a pressure check on the system as advised above.

Would a rebuild on the turbo replace the parts that could be causing a leak? For how cheap the rebuild kits are and since it has 210k on the stock turbo I almost want to just go ahead and rebuild it

I’d figure out the problem before I threw money at it. 

1 hour ago, Reaper22 said:

Would a rebuild on the turbo replace the parts that could be causing a leak? For how cheap the rebuild kits are and since it has 210k on the stock turbo I almost want to just go ahead and rebuild it

I have to agree @Threadzy on finding the problem first. You can flush a lot of cash down the toilet hoping this or that might fix the problem. FWIW my HX35 has 510k on it. Rebuild kits for them are about $50. DAP has them. 

Like myself I ended up with a membership used turbo the bearing were gone. Grabbed a set of bearing and rebuilt the turbo and now still using it years later.

OK guys so I went ahead and whipped up a boost leak checker with some help from a Cummins forum post. Pumped it up to 25psi, well over what my boost was when I would hear the noise, and nothing. Spraying soapy water there are no bubbles on the compressor side of the turbo anywhere, nor on the boots I can access. I can’t hear any leaks at all and in the 10-15 mins I let it sit pressurized no noticeable leak down in pressure. I feared this would be the result since I was getting full 35psi of boost and the truck felt the same making great power. Where do y’all think I should go from here? 
 

I ordered the rebuild kit from turbo lab America because A I didn’t want to have to wait another 3 days to ship if you guys recommended I rebuild it and B rebuilding it sounds like a fun project and it’s got 210k on it and most likely needs it anyway. Plus. With these online classes I’ve got plenty of time to do it 

 

I came across a couple deals just seeing what is out there and I can get an he351cw for $200 or a super B special for $450. Either of those worth going for? Really don’t want a laggy turbo. I’ve got an edge JWA and would swap nozzles if I upgraded. 

Turn a problem into an excuse for more power :D 

Edited September 11, 20204 yr by Reaper22

Fixed! 
@NIsaacs got it right. Sitting here twiddling my thumbs I went to the Napa in town and got a t3 gasket and decided to just replace it since I’ve got nothing else to do and sure enough no more scary sounds with the new gasket. There’s only a tiny bit of soot on the edge, I guess because it would only leak at high drive pressure when the smoke had cleared up? Not sure about that... 
Either way, thank you guys for being awesome as always