Turbo Diagnosis, after removal

[guitaraholic]

I have an T28 (ball bearing) turbo that I took off my car last week because it was making a ticking noise, like it was scrapping against something. So I figured the turbo was toast.

I took it apart, there is no shaft play from side to side, and only minimal up and down (not enough to see, just bearly enough to feel). I took the whole CHRA out and found that the exhaust side "sheild?" is loose. If I hold it down in place, I don't get any scraping at all and the turbo spins just fine. Do I need to secure the back side? I will post some pictures if this will help clarify the question.

Thanks everyone for the help.

[clark]

I have an T28 (ball bearing) turbo that I took off my car last week because it was making a ticking noise, like it was scrapping against something. So I figured the turbo was toast.

I took it apart, there is no shaft play from side to side, and only minimal up and down (not enough to see, just bearly enough to feel). I took the whole CHRA out and found that the exhaust side "sheild?" is loose. If I hold it down in place, I don't get any scraping at all and the turbo spins just fine. Do I need to secure the back side? I will post some pictures if this will help clarify the question.

Thanks everyone for the help.

from your description, it does not sound like you tested for "in and out" shaft play. e.g: push the wheel to and fro the way you stick a straw into your big gulp.

and by shield do you mean the little plate between the exhaust side turbine and the CHRA?

because that is supposed to be "loose" when you take the chra off of the exhaust compressor housing. only when you bolt the chra back to the exhaust turbine housing does that plate become secured.

if you suspect the wheel was touching the housings, look for scoring on your intake and exhaust housings. if you see any, yes, your compressor was touching them and potentially making that noise.

[guitaraholic]

When I meant up and down, I was talking about "in and out" I am sorry about that, and now looking at it that way, I can see how it could have been misinterpreted.

The in and out is only noticable by feel, its like wiggling your teeth. (No not rotten teeth that are ready to fall out of your head...lol, I mean healthy teeth). The movement can be felt, but not seen it's that small.

As for the sheild, yes, I did mean the plate between the exhaust side and the CHRA. I looked and I didn't see any signs of scoring/scraping anywhere, I might have gotten lucky and caught it right when it happened.

As of right now, I just put the turbo back together (well, mostly) and it doesn't make the noise like it use to. (Before, when I first took it off, if would sound like it barely scrapped against something on one side, when you spun it with your fingers, it doesn't seem to be doing that now at all. I am going to hook it up to an air gun and spin the hell out of it, and see if it still does it, if not, I was thinking about putting it back on the car.

Infact, I have an adjustable length WGA from HKS on it, and to be safe, I extended the rod all the way out where the wastegate is open 1/2 way w/o boost. I know it will kill performance, but right now I'm just going to see how it works.

If anyone has any other suggestions or info and what else I should do, I would be glad to hear from you.

[clark]

When I meant up and down, I was talking about "in and out" I am sorry about that, and now looking at it that way, I can see how it could have been misinterpreted.

The in and out is only noticable by feel, its like wiggling your teeth. (No not rotten teeth that are ready to fall out of your head...lol, I mean healthy teeth). The movement can be felt, but not seen it's that small.

As for the sheild, yes, I did mean the plate between the exhaust side and the CHRA. I looked and I didn't see any signs of scoring/scraping anywhere, I might have gotten lucky and caught it right when it happened.

As of right now, I just put the turbo back together (well, mostly) and it doesn't make the noise like it use to. (Before, when I first took it off, if would sound like it barely scrapped against something on one side, when you spun it with your fingers, it doesn't seem to be doing that now at all. I am going to hook it up to an air gun and spin the hell out of it, and see if it still does it, if not, I was thinking about putting it back on the car.

Infact, I have an adjustable length WGA from HKS on it, and to be safe, I extended the rod all the way out where the wastegate is open 1/2 way w/o boost. I know it will kill performance, but right now I'm just going to see how it works.

If anyone has any other suggestions or info and what else I should do, I would be glad to hear from you.

it might have been running dry too. i've actaully had metal shrapnel clog up my banjo bolt that goes into the engine block. it's a very small port so it's easy to get clogged.

check your banjo bolt and make sure it's clean. also i too have done the compressed air test on my turbo. make sure you pour some oil in there before you do it.

[guitaraholic]

Thanks, I didn't think about adding oil to the turbo while doing the test, thanks a ton for the heads up.

I just hope all goes well with it. Yes, I posted about a week about about going the Holset route, but I would rather take my time and shop for good deals, then have to rush to get it done with cheap parts.