Need advice on blown turbo! Why did it happen?

[Maranello993]

Recently I installed a 14b on my 95 GS-T and the turbo ripped itself up. The 14b had 93k miles on it and it had a little more side to side shaft play than I liked, a little up/down and very very little in/out shaft play (whereas my t25 has ZERO). Install had a few problems, I had to remove the turbo to re-tighten the coolant line next to the block, and that same coolant line was touching another so it broke on my once. I fixed it so nothing was touching and it hasn't been a problem. The coolant return line is slightly kinked because it curves. I know that both coolant and oil got to the turbo because I had to fix a leak from the oil return line and the coolant feedline. The turbo still spins freely but the compressor wheel is all ground up and there is now almost 7mm or so of in and out shaft play. The turbo always whined and I thought it was my Dejon tool intake or something. I realized it wasn't when the noise got really loud as the car wouldn't boost past 10 psi with the mbc set at 14 and white smoke puffing out after a pull. When I pulled the intake off something (not sure exactly what) fell out from the front of the compressor. I couldn't find it in the grass and my brother keeps telling me it was part of the compressor wheel. The questions I have are: Why the FRONT of the compressor wheel would get ground away near the shaft, what caused all that in/out shaftplay, what can I correct before I put a 16g in so I don't kill that too, was the turbo just ready to go or was it something I did, and should I be worried that the shavings that resulted got in my motor? Thanks in advance and hope this long post gives enough information. I will upload photos as soon as I can use another computer.

 

[90laserRSfwd]

sounds like the 14b was abused when you received it. Hard to say for sure, just my uneducated guess thus far.

 

[JusMX141]

The questions I have are: Why the FRONT of the compressor wheel would get ground away near the shaft, what caused all that in/out shaftplay, what can I correct before I put a 16g in so I don't kill that too, was the turbo just ready to go or was it something I did, and should I be worried that the shavings that resulted got in my motor?

The front of the wheels near the shaft are often cut from the factory when the wheels are balanced. You can see what I'm talking about on this new 16G compressor wheel:

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The in / out shaft play is caused by the oil hole in the thrust plate being clogged by some foreign object, normally metal shavings from an engine that's on it's way out. I'm not saying YOUR engine is dying- the turbo might've come from a car with a blown engine and had metal in it when you bolted it to your car.

Here's an example of a thrust plate with a clogged oil supply hole- you can see how scored the thrust plate is in the center where the collar rides:

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Here's the same thrust plate next to a new one:

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The shavings that went into your oil pan would be scarfed up by the oil pump where it would be sent to the filter and eventually be trapped. I wouldn't worry; however I'd probably change the oil and filter no matter how new it is just to be on the safe side.

 

[Maranello993]

Yea, my t25 that came out is in PERFECT CONDITION. My motor has seen only the best mobil 1 oil and I change it every 1 or 2k miles. The turbo lasted like a week and like I said it always whined. I've posted pictures of the compressor fins in my profile. The compressor wheel has been ground away by something and I'm not SURE what it was. Thanks for the help guys. Hopefully my 16g install will work out.

Edit: I wasn't so worried about shavings going into the oil pan, but shavings going into the intake. Yes I will change the oil and filter, and the coolant is going to get drained for convenience during the install. And as far as the fins, I'm talking about major grinding, not just those little balancing cuts. I also don't think I mentioned the pulsing squeaking sound that came out of the intake filter at idle and continued as the turbo slowly stopped spooling when I shut the motor off, it sounded like when you brush the fins with your finger.

 

[relmer4]

It looks like the nut is missing that holds the the compressor wheel to the shaft. It is likely that that is what fell out of the intake when it was removed. I would guess someone had the turbo apart and didn't locktight the nut back on. It does'nt look like you need to do anything different when you switch to a 16g. Just make sure all the debris is gone and switch turbos. Hope this helps.

 

[Maranello993]

Wow, I can't believe I didn't notice that. Maybe it was because I was rushing to go back home to Blacksburg from Loudin County (I was literally told to rush and I made them wait while I popped the hood). Thanks for pointing that out!

 

[JusMX141]

The compressor nuts on older 14B's were right-hand threaded. This was later changed to a left-hand thread design because the right-hand thread nuts can loosen during operation due to the direction the shaft turns.

You absolutely MUST use Loctite on the compressor nuts that are right-hand threaded!

 

[Maranello993]

Ok I installed the evo 3 16g and nothing leaks, it holds 8psi until 6700rpm then creeps to 10/11psi. There was both oil and coolant in the old 14b. I'll take it apart and figure out exactly what the problem was.

Edit: The compressor wheel is seized to the turbine shaft and won't come off. I think it surged and undid the nut, which created play that shoved the compressor wheel into the compressor housing and ruined both. The nut ground away at the compressor wheel after it got unscrewed and destroyed the wheel.

 

[spidey7]

My 20g creeps to 20 psi, maybe I should oversize the hole of the ext wastegate...Or my boost controller is not working good?

 

[Maranello993]

BTW the 16g, which is hooked up exactly the same as the 14b was, is still in perfect condition and has no shaft play at all. Just wish I could get some money back for that 14b. Spidev, you could start a whole new diagnosis thread on that. I ported my wastegate inlet and the flapper hole substantially and I also have a tubular o2 housing. I don't have a 20g or experience with, it could be a number of things. Do some searches and find out what other people have done.

 

[Maranello993]

Angelo's Mitsubishi - a set on Flickr

Photos of the 14b

 

[VTEC_THIS]

Wow, that looks nasty. I've never seen a compressor or turbine wheel that messed up!