I thought maybe, but it stays a constant frequency, and doesn't change with engine RPM. It definitely tracks boost though. Like at exactly 16 psi or something. But, I can test your theory by jamming a rag in the gap and seeing if the sound goes away or changes.
I was noticing that the T-bolt clamps don't clamp perfectly round, they kind of egg shape the hose. My gut is telling me that the hoses have enough clamp force to stay attached but there's one thin section where air bleeds out on one of the joints.
Well, my photo host appears to be taking a dump but I solved the whistling noise and also it appears I've got enough spacer on my rear O2 now that I don't throw a code for that either anymore. I have a photo of the joint where I think the noise was coming from. Bottom line, the lower intercooler elbow that comes with the Snabb kit was too small, made worse by the fact that my intercooler doesn't match factory as I previously posted. I replaced it with the Samco silicone hose from my previous kit and the noise is gone.
And this fixed it, although it's a temporary solution. It's over-stretched here and it's also part of the complete samco kit for stock tubing and I'd like to sell it off and recover some money, so it's coming back off.
So I thought I was done with this car, but circumstance had the last possible mod I'd be interested in doing fall very affordably in my lap...
Boom. Stock 19T from a 2000 V70R.
A bit on the high mileage side with some play, but zero evidence of the wheels rubbing on the housings. I'm gonna clean and rebuild it and then drop it in. I watched some youtube videos of how to rebuild turbos and it's super easy, I thought there was machining involved. I'm still deciding whether or not to upgrade the compressor wheel to a billet 19T or 20T wheel, I probably will just because I got the turbo cheap and it's about the max you can mod these cars without doing engine internals. I do need to go research and find out what to realistically expect from the upgrade.
And this is as far as I can tear it down as I don't own a large snap ring pliers. I'll pick one up this weekend. The cool part is that from everything I've read, the hot side is the same on all these so I can do the rebuild and then just stick this in my hotside that's on the car, none of those nasty exhaust bolts to deal with. I plan to get it installed and re-tuned before the end of the summer.
So last week I started tearing it apart, this thing is filthy:
The dirty compressor wheel came off easily enough.
The turbine wheel and bearing section is really coked up badly, I couldn't even get the bearing off. The bearing was scored around the OD like it spun in the housing.
The o-ring wasn't even visible behind the layer of gunk built up in the compressor side.
Oil varnish and heavy wear on the thrust plate:
At that point I ordered a rebuild kit and dumped all the parts into a solvent tank to soak. Then the rebuild kit arrived yesterday! Much faster than I expected.
The compressor side parts came out really nice and clean, almost like new.
The compressor side of the center housing cleaned up pretty good too:
Not so much on the hot side:
This didn't come clean either, it's really hard oil coke I think. Either the engine was burning a lot of oil or the turbo was leaking a lot of oil.
Lots of gunk built up in the oil passages and on the sealing surface in here:
So then as I was cleaning, I went to blow out the water passage and it spit a whole bunch of powdery corrosion at me. It appears that the entire water jacket on this turbo is blocked off by something like stop-leak or some other corrosion. Air does not blow through it. It's a white powdery gunk that I can scrape out, but only so much as the water passages twist and turn inside the housing.
Between that and the extremely hard buildup on the hot side sealing surface that I can't even scrape off with a knife, I'm wondering if this center housing is too far gone to use. I might take it to a motor shop and see if they can clean it out in a hot tank.
Also the compressor bypass valve is toast, so I need one of those. I'm starting to think my best bet will be to just put this compressor wheel and cold side housing on my existing turbo, basically upgrading it from a 16T to a 19T, since the hot side is all the same anyway, and call it good. That or pull the whole center housing and rebuild it with the kit, but that seems like overkill on a turbo with less than 70k miles on it.
I do also have a spare LPT turbo, I should pull it out and see if I can use anything from that. Ugh.
Looks like the PO of this turbo was not a fan of regular oil or coolant changes.
One way to get hot side parts (turbine wheel, heat shield, etc) really clean is glass bead blast. You might want to also polish the shaft a little to give the new bearings a chance. Obviously don't bead blast the shaft. Mask that first. Check with your sources but the center housings might be the same for 16T, 19T and your LPT.
I would not blast the compressor wheel, just get it really clean so that it stays in balance.
Oh, and PS: these turbos have what are called "full floating bearings" which means they are supposed to spin in the housing. The theory is that they spin at about half the speed of the shaft, making the relative velocities lower between the shaft and bearing, and the bearing and housing. The scoring you see is from age and really dirty oil.
So in my research I'm learning that swaps are possible from the 13t through the 18t, and the guts and hot sides are all the same, but the 19t and 20t are one size bigger. So if I try to use my 16T center housing I'll have to machine it. I'll post pictures later. I might not do this swap after all unless I can get this 19t center housing really clean. Gonna see about hot tanking it like an engine block.
Here's the 19T vs 13T compressor wheel. The 16T will be in between. It's a bit surprising that these half millimeter differences change the turbo that much. Then again, at 100,000 RPM a millimeter clearly translates into several cubic feet per minute of flow.
The turbine wheels are identical, I measured them to make sure.
The center housings are different only in this relief for the compressor wheel. 19T on the left, 2mm larger than the 13T-18T on the right.
So that leads us to tonight. I got this for $20 from Amazon:
And this from Sam's club for $10:
Let's get started!
My plan was to blast into the trash can to contain the mess, but no way, it went everywhere. So I took it outside. First pass, it did some damage but not as quick as I'd hoped:
As for rust and surface corrosion/contamination, it does a remarkable job.
The 13T impeller cleaned up pretty nice on the first pass:
The 19T, not so much. Need a combination of soda blasting and scraping to clean it up.
So far I'm impressed with the soda blasting, I went through less than 5 lb of soda (I bought 26 lb) but I had to refill my compressor 3 times just to get done what i got done. I think I'll take the whole can of worms to my workplace where we have a several hundred gallon tank on an industrial compressor, and I can spend some real time blasting the parts. I still have some carbon to blow off, but I think if I can blast for more than 2 minutes at a time I'll make a real impact on the parts. Stay tuned.
At this point, I'm happy with how the 19T housing is cleaning up, so I'm going to try to machine the 13T housing only because it's less corroded and has the same ports as the plumbing on my car. But if I mess it up I don't care, moving one water line is not a problem.
I find myself wishing I went ahead and took the blasting gear with me today but at 7AM packing dirty clothes and baking soda and all that crap just seemed like a hassle, so rather than stay late soda blasting, I figured I'd try to see if our lathe at work could hold the center housing accurately enough. Well I got impatient and did it over my lunch break, so I could have finished soda blasting at the end of the day.
The good news, the lathe dialed right in straight and true, and I was able to very easily open up the compressor clearance.
So now I have two 19T center housings, but one with the correct water piping ports blocked, and a lot less corrosion and coke buildup! It was very easy. All that's left is to finish blasting and cleaning the turbine and the back of this housing and I can rebuild, and then install my newer beefier turbo.
That soda blasting is quite effective! Much easier cleanup than other types of blasting media too.
Interesting that the T-wheels are all apparently the same. That should save you about an hour of chiseling and blasting that caked up wheel. I wonder if the turbine scroll A/R is the same between these models. Might be worth a check since that is usually matched with the compressor.
My guess is that you will have better top end power with this larger turbo, but a bit slower spool up. Will be interesting to see how drivable that will be with the 5M, especially at your altitude.