I have a 95 Miata with a Garrett M24 AR 80. Only turbo i can find online that are similar are the GT2560. Bought it used off of craigslist. It had no shaft play and looked in great shape. It was off of a 240sx that he made to be similar to a Silvia. I have had this on my car for about 400 miles. It was running 10 pounds of boost and running great. Last night coming home from dinner started to make bad scraping noise. The shaft is pretty wobbly and scraping on the inner housing. It seems to have been running hotter than usual for last few months and did have an oil leak at the oil drain. I also am concerned the BOV is not hooked up right. Would a bad BOV cause a failure like this or more like the heat/oil leak? is it a bad tune? read something how ignition timing could have issue? or was it just a turbo with issue I picked up? I have been tuning this on megasquirt without issue. Dont want to buy a new turbo and have same thing happen. I have pretty much followed the car passion broke and boosted build exactly. I have rx8 injectors, cast iron log manifold, ebay intercooler and piping, ebay bov, innovate wideband, megasquirt PNP2, coolant reroute, 2.5 inch downpipe and exhaust.
Any help would be appreciated. I am going to take it apart soon to see what exactly with turbo is. The turbo has shaft play and compressor wheel has some damage. none to the exhaust side is damaged. Could I also rebuild or should I scrap it and move on?

 

BOV is separate from turbo woes unless it wasn't opening and you were experiencing compressor surge which afaik won't kill a turbo after a few hundred miles. Oil drain issue is separate from compressor woes it seems. Rebuild turbo, tighten/replace gasket/replace oil drain line, follow oil drain line process for BOV. What was running hot? Look at 10 other failed turbo threads and one has at least one of your problems.

 

I know the turbo should be hot, but it melted part of the wideband line so thinking it was hotter than it is supposed to be. The coolant temp has been fine. Also left off that there was some smoke from turbo, which I thought was part of the oil leak.
Thanks Monk

 

depending on the turbo model, if its a ball bearing turbo off a s14 s15 silvia, it cannot be rebuilt and you can buy a new center section from garrett. s13 t25 turbos are journal bearings and can be rebuilt.

only thing that can kill a turbo like that is bad oil supply/drain. post some pictures how you have this setups.

 

I have the same turbo. It can be rebuilt.
30-40$ cheapo ebay kits exist, or gpop shop has a higher quality kit for around 80$

seeing the inside could help diagnose the issue, but it sounds like it needed a rebuild from the start.

 

the bov was not working correctly, the WB melted. I would fix that stuff first.

 

check the oil feed and drain. If the turbo is not getting oil then it will develop shaft play, or in the case of a ball bearing turbo too much oil can hurt it. If it is ball bearing make sure you have a restrictor installed. A leaking or bad bov isnt going to cause the turbo to fail. Wrap the wideband sensor wires in heat tape and tie it out of the way so it doesnt melt.

 

Yes it can. not normally at 10 psi, but on an old turbo, quite possibly. The oil restrictor could also be a culprit.
Did it have the water connected?
Are the flow directions correct? water flows UP through a turbo, not down.
Was it just a really old 2560R? was it starved of oil?
Where is the oil being supplied to the turbo from?
Why dont you have a heat shield on the manifold / turbo , to prevent melting things?
How long was the WB non functioning?

 

If the BOV was leaking in boost (common problem) the turbo could have been spinning up to a crazy high speed to make the boost demanded of it. This would put it way off the efficiency island, making it hot, and also lead to premature wear.

 

I think its SUPER unlikely that a leaking BOV will cause a turbo to overspeed and fail. It would have to be a giant leak for this to happen, and you would notice much slower spoolup and the car would not drive that great it would feel very laggy.

 

...

 

surging kills compressors. a non working BOV can cause surging.

 

You guys are on your own.

 

let's all keep speculating with absolutely no proper info or diagnosis or anything

 

it doesnt kill it in 400 miles, it takes a LONG TIME

 

That's "compressor stall." "Compressor surge" is a different beast and kills turbos. Compressor stall takes forever to kill a turbo, and just plain old might/probably won't.

 

Was there a lot of 2 stepping in that 400 miles of boost?

 

2 steppin to 50 cent

 

I did have an oil restrictor on the turbo. The water lines were hooked up. The oil feed was at the top of the turbo. so the water lines were on either side. In the 95 1.8 i used the high pressure feed from the block. I need to do a heat shield, but havent. The WB went out probably 10 or so minutes before the turbo went out. Wasnt tuning or anything so thought i could make it home without issue. Did notice on the way there before any sound or WB breaking that the boost didnt come on quite as fast and felt less responsive. The car wasnt overheating I monitor with coolant temp gauge. The turbo was getting oil because it had a leak at the oil outlet. Will upload picture of turbo. I am taking it apart now. The turbo snap ring is giving me some issues.

 

Ill post more when i take it apart. Thanks for the help thus far!