What happened to my turbo?
 

Guys,
I'm hoping that one of you can suggest what might have happened to my Begi Churbo. I've been running it for ~4 years with no problems up until recently when it started to sound odd and feel like there was a boost leak. I pulled the turbo today and found the compressor wheel vanes almost uniformly damaged. There is some radial and axial shaft play, but I don't think it is enough to have caused the damage shown. The uniformity of the damage makes me think that FOD is also unlikely. I've heard that compressor surge can cause damage, but I run a recirculation valve and never noticed any surge sound.

Next question is what do I replace it with? I want to stay inexpensive, so probably churbo, because I don't think I'll be keeping the car a whole lot longer. I was satisfied with the performance so I'm leaning toward just ordering a replacement from Begi rather than gamble on an total unknown from ebay.

Thanks for your help.

https://www.miataturbo.net/attachmen...ine=1431303118

Something that wasn't suppose to be there passed through........missing any hardware ? I'm not seeing a nut on the turbine shaft.

Wow! That looks like $hit!!! Funny thing is, the compressor housing looks undamaged just the wheel itself.

This, take another photo on an angle. If the nut is missing and the shaft actually backed out, then that means there might be turbine wheel damage as well.

I'm definitely seeing a nut on the turbo shaft, and I have shit eyesight. Get yo eyes checked.

Here's a side view and the turbine wheel. It looks like there is a small nut in place on the compressor side and there isn't much front to back shaft play.

I guess it makes sense that a piece of FOD could have damaged just the longer blades until it broke up enough to pass through. Or it was still in the intake and I didn't notice it while I was pulling the turbo off. Either way, I should probably see if there are any bits in my intercooler and maybe do a compression and leak down test to make sure the engine is still healthy-ish.

https://www.miataturbo.net/attachmen...ine=1431308361

https://www.miataturbo.net/attachmen...ine=1431308361

I'd be checking your charge pipes and hoping that the intercooler trapped whatever passed through.

Your chances of consistency with BEGi are exactly the same as with Ebay. In fact, I'd wager that some "ebay companies" like Kinugawa would likely have more consistency in their products.

FOD.

Shooter,
All of our Chicomturbos have come directly from the US importer. You have not experienced a turbo that decided to give up, rather one induced to yield to other influences.

If the damage shown is other than foreign particles, I'll need to go back to square one or two.

All the dings in the surrounding material were created while the object bounced around. The wheel damage suggests to me no other possibility.

Most likely the object got beat into granules and are now somewhere in the intercooler, if one is present. If not present, or got through thr IC; aluminum debris would burn up in the chamber and pass right on through the chamber and out the exhaust. Virtually no possibility of damaging anything in the chamber. If steel, likely the same story, but a greater possibility of stuck in the IC or scratching the turbine if it got past the IC.

Pull all the sparking plugs and look for very small aluminum balls attached to the ceramic insulator surrounding the center electrode. A ten power little magnifier/scope is helpful. The balls are shiney and are remains of the aluminum stuff that came from somewhere. These same little balls also show up after a severe dose of knock, so its not cast in stone that they came from elsewhere. However, with alaly lost from the compressor and if shiney balls are on the ceramic, I'd suggest they are related.

If any plug appears to be dinged, do a compression check to soothe your worries.

And, of course, pay heed to my advisory group above.

If no balls are found and the plugs are relatively clean, no damage is likely.

There is no possibility of compressor surge breaking up the compressor wheel.

corky

Are you, by chance, running a recirculating BOV?

Yes

Check to see if it is missing any pieces.

Thanks for the input. I'll pull the intercooler tomorrow to see if there are any pieces remaining. With the positioning of the recirculation valve I doubt that a piece could have made it to compressor wheel but I'll check that as well. The odd thing is that I don't recall having the intake off anytime recently so I'm not sure where the FOD came from.

Wire can come off a filter element such as a K&N from time to time, but that's some serious damage and it does not look like something a wire would do. That thing self-milled pretty comprehensively. I would guess something spherical-ish even.

Wow that is serious carnage!

%100 that is foreign object damage. Now what caused it is the key but you can see what ever it was was bouncing around the compressor inlet and had been for a while. We see everthing from wreches, to nuts, to filter material, compressor wheel nuts, ball bearings.

I finally had time to pull the intercooler to inspect for debris and didn't find a thing. I also pulled the plugs as Corky suggested and didn't see any evidence of melted aluminum or damage to the insulators. I'm starting to wonder if the object never actually made it through the compressor and I just didn't notice it falling out when I pulled off the intake tract.

I could believe that a small rock composed of sandstone or the like may have just disintegrated in there. Prolonged exposure to small particles (sand) could also do that, but would probably be a bit more even in its wear pattern AFAIK.

Edit: No way on the sand, I forgot about those rings on the inlet. It was something that got spun around and milled the snot out of that area. Hose clamp would make sense, though you would have probably found some debris or something Is would think. I vote rock.