Burning rear turbo bearing (hot side)
 

Hmm.. I seem to be having an issue where I'm doing some not-so good things to the turbo bearing on the hot side.
Last 2 bearings, the oil has seemed to be dark on that bearing.
I'm running an oil feed from a stock turbo feed port on my block to a 6an line. That goes into a very large filter, and outputs to a 4an line to the turbo.
No restrictors in the line. Oil flow during cranking looks good, fills a 1/4 quart very quickly.
I just went to a t3 .60/.63 water cooled garret turbo. After about 180 miles, it feels like it's starting to get loose again. I'm going to open it up and look at the bearings, but I suspect it's the same hot side bearing failure.

EGTs under control.. 1350 peak, 950 cruise. Measured immediately after #4 exhaust port.

Oil pressure reads good, 25psi idle to 70psi running. This isn't measured at the turbo, but at the standard oil port on the other side of the block.

To debug oil problems - and I'm assuming this is still an oil problem - what do you guys recommend? Perhaps an in-line pressure gauge at the turbo feed?

Re: Burning rear turbo bearing (hot side)
 

We've seen -4an still manage to be pretty big and recommend a 1/16" restrictor for the feed. I would check your oil dump and see if it is nice and flowing not to mention within 30* of vertical. Also, your EGT probe should be on the THIRD runner not 4th.


JP

Re: Burning rear turbo bearing (hot side)
 

Big is the idea. Why are you recommending restricting the line if I'm burning /coking that rear bearing?


Oil dump is 1/2" ID, vertical, I can stick something under it, but it's positioned very well and has no sharp bends.

This is a 22RE, inline 4. #4 is where I'd expect the highest temp to be.

http://lakebox.dnsalias.com/photos/1.../t3-60eng3.jpg

http://lakebox.dnsalias.com/photos/1...urborebld1.jpg

Re: Burning rear turbo bearing (hot side)
 

Re: Burning rear turbo bearing (hot side)
 

Better than the last one.... The question(s) still stand, however..

Re: Burning rear turbo bearing (hot side)
 

yeah, but you aren't the only one with a new manifold!

all i can think of is, your block doesnt have enough feed to get to the turbo. tee off of the sending unit hole, plug oem turbo feed

Re: Burning rear turbo bearing (hot side)
 

New manifold? I've only had one!
On your manifold, my only conern would be clearance with the stock distributor and power steering assembly if you still have one...

I've thought about doing what you suggest... A lack of oil flow would do it... Was wondering if oil pressure can and should be measured at the turbo itself?

Re: Burning rear turbo bearing (hot side)
 

no PS so im good, you could always switch the pressure sensor with the oem feed, and just lube it from sensor feed.

doesn't matter if you have 1500psi getting to the turbo, if you can't flow anything more than a few drops, which that big filter looks to be hogging any volume that you're getting across the line

Re: Burning rear turbo bearing (hot side)
 

I'm an idiot, that's why. I don't know WHY you have a inline filter, but I'm agreeing with c0mpl3x and that could be holding things back a little bit. Then again you said it filled a container rather quickly so I'm not quite sure.


I have a question for you. Pics of your oil dump off of your turbo. Just curious on how you ran that on account of it appears you made your very on oil lines and I want to see how you mounted it on the turbo itself.


Sorry I couldn't be too much help and I apologize for the previous n00b answer; HOWEVER, common runner is #3 for an EGT probe this I'm sure of (atleast for Honda exhaust manifolds). Don't know HOW big of a difference it will make (probably minimal) in the overall case of things and your max temp is far from severe.


JP

Re: Burning rear turbo bearing (hot side)
 

I'm running an inline filter because I've got a new motor. New motors tend to generate very fine debris. Fine debris + 100k rpm of a turbo = bad mojo. The inline filter is huge, it's the size of the oil filter for the engine. 3/8 inlet / outlet.
I had these issues before I had a large inline filter also.


If you mean the oil drain, it's pretty basic. I've got a fitting that works with the garrett center section going to a piece of brass plumbing pipe. The pipe is about 4-5" long, then goes to a high temp silicone hose that was designed for oil/fuel.

http://lakebox.dnsalias.com/photos/1...urborbld11.jpg
http://lakebox.dnsalias.com/photos/1...urborebld1.jpg



I had issues with high EGTs to start with, I figured conservative timing was good.. wrong.. conservative timing = high EGTs.
I don't think it matters if the probe is on #3 or #4.

I'm still hunting as to why I'm burning turbo bearings.. I'm probably going to put a mechanical oil pressure gauge on that inlet and see what happens.

Re: Burning rear turbo bearing (hot side)
 

I didn't think you had an oil dump flange and was curious how you did it, but alas you have one. Well, as you've said the filter was there before and didn't cause it.....or could it have just been causing it and now it's finally bad? I really wish I could give you good advice here, but as you can see I'm pretty much in the dark. Bump for your answer.


JP

Re: Burning rear turbo bearing (hot side)
 

what weight are you running for oil?

Re: Burning rear turbo bearing (hot side)
 

I've been running 10W-30, straight dino as I'm in break in.. I can go to a thicker oil, synthetic - might impact my ring seating, but at this point I really need to the turbos to stay together....

I measured the oil pressure tonight at the turbo oil feed line, post oil filter. 20psi at idle, 60-70 psi at 3k RPM. No restriction in the line... That's more than enough pressure through a 4an line, perhaps I've got a crapola turbo... (reman, was told genuine garrett / dynamically balanced)

Lateral play is at .030" - basically at the limit of what it should be without turbine/housing contact...

Dunnoooo.. damn thing is an expensive pain in my balls.

Re: Burning rear turbo bearing (hot side)
 

Well since its an old turbo, and looks to be a T3, I'll take a guess here - its your turbine seal thats FUBAR. Its probably the piston seal, meaning it looks like a piston's ring you'd normally think of. Exhaust pressure keeps the oil in the chra, and if you have very high exhaust mani pressure, a restrictive exhaust, as well as a worn seal, there could be 1200F gasses passing that seal and burning the oil.

I'd suggest watercooling the turbo (it likely has the ability), and/or letting the turbo cool down every time before turning the motor off.

BTW what exactly is the issue? Just the bearing collecting a bit of coked oil, or smoke from oil leaking into the turbine housing?

Re: Burning rear turbo bearing (hot side)
 

10-30 way too liquid at high temps for any turbo car.
0.022! is already too much shaft play IMO and it's the garrett spec.
0.03 is way too much shaft play, it'S actually enough play to cause wear of the turbing piston rings and make this turbo a leaker. The turbo itself it the cause of your problems i am 99% sure.
I say: 5-50 synted oil. 1/16" restrictor, 1/2" drain and a profesional / warrantied turbo rebuild maybe with watercooling upgrade and you're good to go.

Re: Burning rear turbo bearing (hot side)
 

The turbos in the above photos is not the turbo I'm using currently, they're just photos for example of how I did the oil return. The turbo I'm using is a garrett t3, completely rebuilt and balanced.. It's not new from the factory garrett, but it should have been fine.

The turbine seals should be fine. Less than 200 miles on the turbo. Boost pressure less than 10 lbs. It's already watercooled...

Appreciate the guess though.



Blasst,
As stated, I'm running a water turbo now.
I've switched to a 15w-50 synthectic Mobile1, even though this isn't the best idea for new motor break in. I did it a week ago and the turbo was already out of spec.
I don't know that I'm willing to put a restrictor on it as long as I'm destroying bearings due to oil flow.. If I start getting oil past seals, I'll start restricting it. There was no restriction in the factory turbo setup and the guys I know running journal bearing garretts aren't running them with this motor..

I'd buy "warrantied" turbos, but unless they're a no-fault warranty they're essentially worthless.. 98% of the turbo failures are going to be be attributed to some customer issue from what I've seen... Probably rightfully so - especially if shops are going to fault the type of oil (dino vs synthetic) or oil weight.

I'll post up some photos when I get it apart.

I added a BOV also to prevent compressor surge. 1G type valve.

Re: Burning rear turbo bearing (hot side)
 

No news is good news? What's up?


JP

Re: Burning rear turbo bearing (hot side)
 

Yes all warranties are limited, that's normal.
I personaly never void a turbo or rebuild warranty because of the type of oil, or lack of a restrictor.
Only obvious signs of abuse or neglect such as dented wheels, if you tampered the CHRA, or if it shows signs of oil starvation or gross contamination. warranty returns are rare. Case when we have to void it, even more.

Re: Burning rear turbo bearing (hot side)
 

Rear bearing looked OK - not an oil issue.
Turbo out of spec, going back for repair. As I opened it, I voided the "warranty"