Pink crust on turbine wheel?

**Charles.waite** · 02-09-2016 01:41 PM

Hello ladies and gents. Welcome to another edition of "Is this normal"!

So a while back I bought a used k03 locally, it actually seems in really good condition, but I'm rebuilding it anyway. Anyway I was a little bit confused about what I saw on the hotside wheel:

Its sort of pinkish/white fairly hard but scrapes off with a small flathead. There was also a ton of black coking/buildup underneath that ring flange thing between the wheel itself and the chra that scraped off really easily. My thought being the bearing section was seeping oil when it was being used previously.

But what about the pink stuff? I assume its coolant. You thing the CHRA was leaking coolant AND oil? I plan on getting the it media blasted to clean it up because I would imagine that gunk would really affect the balance and efficiency of the turbo. So its not a huge deal, just curious if anyone has seen this before and what the cause ended up being?

**p0isin** · 02-09-2016 02:00 PM

My guess would also be coolant. Not sure on the root cause however.

**vce1232000** · 02-09-2016 02:17 PM

Turbo bushing-shaft failure allows coolant to leak into the intake compression chamber

. Mic

out the shaft for wear tolerance

**Charles.waite** · 02-09-2016 09:05 PM

There is some wear on the shaft, at least there are two polished sections where it rides on the bearing. I'll snap some pics later tonight.

**yeoj112689** · 02-09-2016 09:24 PM

I know nothing about this topic but that picture is pretty cool looking.

**Charles.waite** · 02-09-2016 11:49 PM

Isn't it cool though? I find this sort of stuff really interesting, taking complex mechanical contraptions apart and figuring out how they work.

Anyway, more pics!

Some nice carbon buildup on the base of the shaft. And you can see the parallel wear marks on the middle of the shaft where the bearing were riding. You can also get a better sense for how thick that pink crust is.

The base of the hot side. There was a TON of sooty/sludgy carbon buildup and I wouldn't be shocked to find out this turbo had seen some overheating/oil pressure issues in its lifetime.

And finally the bearing. Original one is top right. You can barely make out some dents in the v-channel where the retainer was wearing against the bearing. The replacement bearing is bottom left.

**vce1232000** · 02-10-2016 08:12 AM

Mite want to

some emery cloth over the shaft where the wear grove is.

a little ruff

. Check clearance where worn at with a micrometer. If in specs re-use. I would

the shaft and check for run out and side to side play

**Charles.waite** · 02-10-2016 08:22 AM

Well A) I don't have specs for that and B) I don't have a mic so I can do neither. I have a cheap digital caliper but I don't think it's going to be accurate enough to to show any meaningful data there.

Besides I'm not going for perfect. Just good enough. I am going to need a micrometer at some point when I rebuild my engine but it's not in the budget atm.

**vce1232000** · 02-10-2016 08:58 AM

Well guess your gonna pass emery cloth on the shaft. Clean and

back together and hope for the

...

**Charles.waite** · 02-10-2016 10:11 AM

Originally Posted by vce1232000

Well guess your gonna pass emery cloth on the shaft. Clean and

back together and hope for the

...

Yea pretty much. The main reason I'm even doing this is so that I can swap the turbo out for my current original one and eliminate the turbo as the source of my oil burning. If its not the cause I'll likely just throw the original one back in, or have the CHRA rebuilt and balanced professionally or something.

**audihere06** · 02-10-2016 10:58 AM

Did your rebuild kit come with a different style oil bearing? Curious because the stock one has two small holes, and when i had mine rebuilt the new one has two large holes and several other small holes.

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**Charles.waite** · 02-10-2016 11:18 AM

Yea initially it did come with a different bearing. I ordered a regular OEM style bearing separately when I realized the difference. I'm not sure I want to be the guinea pig for the dual channel bearing though...

**aluthman** · 02-10-2016 02:15 PM

Originally Posted by Charles.waite

Well A) I don't have specs for that and B) I don't have a mic so I can do neither. I have a cheap digital caliper but I don't think it's going to be accurate enough to to show any meaningful data there.

Besides I'm not going for perfect. Just good enough. I am going to need a micrometer at some point when I rebuild my engine but it's not in the budget atm.

Mail it my way and I'll mic it after cleaning it.

**vce1232000** · 02-10-2016 02:20 PM

Originally Posted by Charles.waite

Yea initially it did come with a different bearing. I ordered a regular OEM style bearing separately when I realized the difference. I'm not sure I want to be the guinea pig for the dual channel bearing though...

All the turbo

are using the dual feed bearing for better longevity and

. I currently have the dual feed in my turbo set up

**audihere06** · 02-12-2016 11:07 PM

Originally Posted by vce1232000

All the turbo

are using the dual feed bearing for better longevity and

. I currently have the dual feed in my turbo set up

Dual feed being the larger holes? Pics? I'll show you mine if you show me yours... Turbo bearings that is.

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**vce1232000** · 02-12-2016 11:15 PM

Originally Posted by audihere06

Dual feed being the larger holes? Pics? I'll show you mine if you show me yours... Turbo bearings that is.

I haz no pics

. I sent my turbo assembly out for the re-

.

**audihere06** · 02-12-2016 11:15 PM

Ah. My rebuild guy gave me my parts back ill try to get some pics

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**vce1232000** · 02-12-2016 11:20 PM

Originally Posted by audihere06

Ah. My rebuild guy gave me my parts back ill try to get some pics

Lucky you

. My original chra unit grenaded

. Nothing was salvageable

. So I had to secure another used one and had my re-

that one.

**Charles.waite** · 02-12-2016 11:20 PM

Wish I'd seen this earlier I popped most of the chra back together this afternoon just for kicks. I'll probably take it apart again though. I'll snap a pic when I do.

Adam I might pm you and send you my wheel. Stay tuned.

Also also my rebuild kit is sort of iffy. The goofy shaped retaining flange for the bearing (the one that has tangs that fit into the bearing recesses) didn't fit well and the finish of it was junk so I reused the original. And then the cover that goes on top of the trust bearing was missing one of the two retaining nubs so I reused the original there also. Sort of annoyed but what can you do. Everything else was great.

**audihere06** · 02-12-2016 11:27 PM

Originally Posted by vce1232000

Lucky you

. My original chra unit grenaded

. Nothing was salvageable

. So I had to secure another used one and had my re-

that one.

Here is my bearings new on the left and stock on the right. Also included my old exhaust wheel with shaft to show damage for those interested.

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**Charles.waite** · 02-12-2016 11:34 PM

That's the same as my bearings. Left side one is the dual channel the right side is the original.

**vce1232000** · 02-12-2016 11:38 PM

Big difference

in size of the lubricating oil ports

**vce1232000** · 02-12-2016 11:39 PM

Originally Posted by Charles.waite

Yea initially it did come with a different bearing. I ordered a regular OEM style bearing separately when I realized the difference. I'm not sure I want to be the guinea pig for the dual channel bearing though...

Which one did you end up using then

**Charles.waite** · 02-12-2016 11:57 PM

I used the dual channel. Seemed more exciting. And if you're running it with no ill effects then why not.

**vce1232000** · 02-13-2016 12:04 AM

choice imo

**mec** · 02-13-2016 09:14 AM

that crust is just schmegma

**audihere06** · 02-13-2016 11:18 AM

Originally Posted by Charles.waite

I used the dual channel. Seemed more exciting. And if you're running it with no ill effects then why not.

I haven't had any issues with the dual channel, but theoretically wouldn't the larger oil channel lower the oil pressure at the turbo?

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**Charles.waite** · 02-13-2016 12:26 PM

Originally Posted by audihere06

I haven't had any issues with the dual channel, but theoretically wouldn't the larger oil channel lower the oil pressure at the turbo?

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Given the carbon buildup I saw I'd rather have the increased flow over slightly higher pressure to the shaft

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