Jump to content
HybridZ

Damage to the compressor wheel


Zmanco

Recommended Posts

I was pulling the turbo to install plate locks on the manifold nuts and noticed this damage to the compressor wheel.

 

post-1744-005197700 1342760359_thumb.jpg

 

post-1744-032876100 1342760366_thumb.jpg

 

I've never run the car without an air filter attached so am really surprised to see this. It looks like something hard was rubbing against the blades. There is also more lateral play than there used to be - enough that the side of the blades can just begin to touch the housing, although the wheel still spins freely.

 

I've looked inside the tube and cannot find anything at all. Any suggestions for what caused this?

 

Also, looking for suggestions on where to source a new wheel? Rebuild kit?

Link to comment
Share on other sites

I actually bought a turbo off ebay that had similar damage. I dont know what caused it the guy said it was on a running ZX, my only guess would be debris. With them spinning that fast almost anything can cause damage I assume.

 

I ran a piece of panty hose through mine with no damage, must have been something tougher than that. haha

Link to comment
Share on other sites

I thought about what might have caused this some more and the only thing I can come up with is there was a track day where the intake hose had rubbed and allowed the rubber to separate from the metal coil that gives it shape and it had partially collapsed. At first it was a mystery why the engine was losing power on long straights but I later found the damaged hose in the garage. I don't recall looking at the inlet then so maybe the damage had already been done? It's been a while but IIRC the collapse was 6-12 inches upstream of the turbo intake so I can imagine that the collapsed rubber tube might have been pulled against the compressor. But given it's rubber, I don't think that explains the deep gouges I see on the leading edges of the compressor.

 

Also curious about the lateral play in the shaft on the compressor side. I checked my logs and the turbo was purchased new 17k miles ago. It's a genuine Garret and has 9 track days for a total of about 1000 miles of track time. Is this just the normal wear and tear that comes from running on the track? FWIW, I've always run Mobile 1 10W30 synthetic, have a 25 row Earl's oil cooler and am careful to let the engine idle after hard running to cool before shutting down.

 

Also, I can just barely feel a little play on the turbine side, but cannot see any movement, so I suppose the bearing wear is all on the compressor side. Should I just buy a rebuild kit and replace the bearing? Is there more to it than that? Any suggestions on resources I can study for rebuilding turbos before I tear into this?

Link to comment
Share on other sites

The metal coil in the rubber hose probably rubbed against the turbine. Those pieces have also gone through the engine and lateral play in the turbo was most likely caused by the damage. Get the turbo rebuilt, remove your oil filer and cut it open to check for metal, change the oil, and do a leak down test on the engine.

Link to comment
Share on other sites

I already have the head off and there's no visible damage I can see in the cylinders or the combustion chambers. Also, as I recall, the metal coil of the hose had remained intact, although I'm thinking the same thing as johnc that it's the likely culprit - even though I can't explain it.

 

Now the challenge is to find a place to balance the assembly after I rebuild it. Anyone know of a place in the Denver area? I'd rather not have to ship it out.

Link to comment
Share on other sites

FO!

 

Foreign Object Damage.

 

Likely it was ingested, threw the wheel out of balance, and as that imbalance worked and worked, your bearings are getting damaged.

 

Looks like you have something that was hitting the inlet taper to the eye on the scroll casting. That may be the 'bounce point' where whatever went through the turbo bounced off at high speed before being ingested.

 

You say you had a tear in the inlet piping? Chances are you ingested small rocks, etc during your time there, through that opening (dust throwoff up in the air) and that is what caused your damage.

 

Air takes the path of lowest resistance. It would rather suck through that hole, than through any filter!

Link to comment
Share on other sites

I ordered a new compressor wheel and rebuild kit from G-Pop Shop. After I rebuild it I plan to send it back to them for balancing. I can't find a single shop in Colorado that balances turbos. Is it a rather specialized skill, or perhaps the market for it isn't that large?

 

And Tony D, this wheel was only a little over $100. I imagine that one is precious.

Edited by Zmanco
Link to comment
Share on other sites

  • 2 weeks later...

I purchased a rebuild kit and new wheel from G-Pop Shop and am sending the center section out to them for balancing. I upgraded to a 360 deg thrust bearing while I was at it.

 

Here are some other pictures of the wheel. The deep gouges lead me to think that it wasn't the rubber from the intake hose that did the damage. Unfortunately I don't think I'll never know for sure.

 

post-1744-085478500 1343828497_thumb.jpg post-1744-040769200 1343828502_thumb.jpg

Link to comment
Share on other sites

I can tell you it was a 'rub' from something that protruded into the turbine inlet and then was removed. I don't see any evidence of passing through the splitter vanes on the wheel, which if something went THROUGH the inlet, it would go and hit those vanes or otherwise scar the surface finish on the wheel where it passed.

 

I don't have a good side view, but it is possible the wheel was rotating in reverse when it happened... backspin damage, it's hard to tell but the direction of the 'pulled metal' generally looks to coincide with direction of normal rotation so something was sucked into the inlet, but couldn't get through....

Link to comment
Share on other sites

  • 2 weeks later...

Yasin, the T3/TO4E turbo with spacer blocks access to getting a wrench on some of the turbo nuts unless the manifold is removed from the head. And it also makes it really hard to get to the manifold nuts while it's on the car. It's easier and takes less time to remove the head, at least for me.

 

FYI, thought I was going to put it all together last weekend but turned out one of the exhaust manifold studs broke off. Easyout failed so I had a local shop take it out yesterday with a plasma tool (way cool) and am now waiting for the new studs to arrive from McMaster later this week.

 

This "little" issue has turned into quite a project. Car has been off the road since the last track day 5 weeks ago ... :(

Link to comment
Share on other sites

Ok gotcha makes sense. Removing my turbo and manifold is also tricky, so certainly understand removing the head. I recently had to deal with broken exhaust manifold studs and had to buy this kit to remove the pieces that broke off flush in the head..just needs a steady hand:

http://www.threadkits.com/time-sert/metric-series/kits.html

 

Hope the car gets put back together soon!

Yasin

Link to comment
Share on other sites

Yes, I have a kit like that for the valve cover bolt holes :) Hardest part I found for the exhaust stud was drilling the pilot hole in the center of the broken piece. Even after using a punch, the drill bit wanted to walk as the surface wasn't flat in the center.

 

In my case it was the stud that connects the turbo to the manifold. Interesting that one of the other studs was slightly bent which probably explains why it broke off. I installed those new when I first built the motor so know their history. The only things I can imagine is that the vibration from driving with the turbo loose (not very loose, could just begin to hear the exhaust leak) might have bent it? Not sure I like that explanation, but don't have a better one.

 

As a side note, while the L engines are rather durable once set up properly, these little nagging issues are frustrating. I suppose if I didn't track it I might not see these though ... or at least they would take longer to show up.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...