The Project Pad

So I noticed an oil leak starting from teh turbo as I was getting the car running over the past few months. At first, I thought it was the gasket from the drain line. After replacing that gasket and torquing everything down, I came to the realization that the oils is coming from between the hotside and the center section...



As you can imagine, I'm fearing the worst right now that the seals in my turbo have mysteriously died and I'm on borrowed time with this turbo. Being a GT2871, you can imagine I'm not too thrilled about this as it's more $$ and time that I don't want to deal with at the moment.

Any thoughts/suggestions/opinions? Do I run it until it completely blows? It's actually leaving a tiny puddle as the car idles up until the housing gets hot enough to just burn off the oil.

Not catching a break right now :(

I'd change the oil. no starts situations tend to throw a lot of gas into the oil and thin it out.

I can fix the GT if it is the seals, so worse case it is only a couple hundred dollars, not a thousand.

How does the shaft feel?

Just make sure the oil isn't coming from the bottom end. If the turbo inlet is dry and the outlet is wet, for sure turbo is getting oil past the "seals". Seals are really just piston rings. Just like piston rings, excessive crank case pressure can cause oil to blow past the rear seal and into the exhaust. How is your crank case being vented and how is your drain situation?

Hank, thanks for the info.

I have change the oil, and the oil coming out is not clean fresh looking oil that went in, so hopefully it's residue like you had mentioned from the thinned out oil from the 6 months of starting that I tried to do!

The outlet of the turbo was dry (cold side), this is literally running between the hot side housing and the center assembly. I will run it for a little while and hope that it "heals" itself. Need to figure out the tuning first so I can actually drive it up/down the street. Right now, it's not very happy. It revs, but not a full range.

BTW, I have a catch can that theoretically drains back into the crank case. I need to double check it and see how it's acting, but I think it's OK. It's on the "to do" list.

Gosh I wish you were on Vems so we could look at your files and tune it 90% remotely.

I welcome sponsorship, but unfortunately I don't have the $$ to invest.

If I had realized at the get go this was going to be such an ordeal, I wouldn't have a) messed with swapping out the Ib or b) bought the VEMS instead, since I would have spent roughly the same amount at this point on top of selling off my Ib.

Hindsight is always 20/20.

I don't understand why oil would be leaking from between the center section and hot side. That fit is supposed to seal air in let alone liquid. I've seen turbos spew oil into the downpipe without leaking at all at that joint.

this is the exact same thing the billet k26 is doing on my mc2

Most turbos geometry on the hotside is such that the oil would have to cross over the CHRA to hotside flange that is not o-ringed or gaskets. If there is oil getting past the rear seal(remember, piston ring, not a 360 rubber seal), it will fall in that void.

Just like I told Corey, if blowby is present, and crank cases are being pressurized, the oil will leak past the seal and into the exhaust housing. Several times in my life I have assumed that a new engine has perfect compression and leak down, only to find that it wasn't the case by actually doing the tests. In my experience any more leak down than 10-15% tends to give these i5's breather system a run for their money. New broken in engines usually have 3-4% leak down, and high mileage healthy engines usually have around 5-10%. If you are above those figures, there are likely scratches from either washing cylinders down trying to start it without burning off the fuel, or just good old fashion detonation.

I totally understand where the oil is coming from if it is leaking past the turbine-side seal, but I just can't believe it is coming out that much at the turbine housing-to-chra "snap" (or joint, fit, whatever).

I guess whether it is leaking or not is neither here nor there though. Take your downpipe off and see if you have oil on the turbine. If so, then that's definitely where your exterior (to the turbo) leak is coming from (rather than from the feed, drain, etc.). Then you just have to figure out if it is coming from the engine or the turbo.

My HX52 had oil on the turbine when I bought it. I replaced the rear oil seal in the turbo in under an hour and it was squeaky clean after that. Silly Garretts

removing the downpipe and/or turbo is a royal royal royal PITA w/ this car, since it's a 20vt. It's not easy to see the bolts, the DP is tight in there and doesn't come out w/o motor removal, etc... lol

I'm going to wait it out and see if it stops peeing in hopes it's what Hank mentioned about just thinned down oil. If I start to notice a consumption issue, I will get to messing with the turbo. Hope it won't come to that, though.

90% of the time, it is not the garrett, it is the poor engine that is pressurizing the crank and therefor the oil drain/turbo chra. My bet is that the HX52 you bought didn't have a bad rear seal, it was just in a powerplant that had a pressurized crankcase on boost that forced oil pas the seal. It is extremely difficult to actually blow out a rear main seal on most turbos. The piston ring doesn't actually spin with the rotating assembly, so it virtually does not wear. It stays stationary on the bore of the CHRA, and the Only time it does wear is when the turbine/shaft gets so hot that it A) collapses the spring tension in the piston ring, allowing for oil to seep out or B) the shaft gets so hot that the ring starts to spin, and when that happens it toasts the CHRA as well.

Yeah.

Yeah.

Hank wrote:90% of the time, it is not the garrett, it is the poor engine that is pressurizing the crank and therefor the oil drain/turbo chra. My bet is that the HX52 you bought didn't have a bad rear seal, it was just in a powerplant that had a pressurized crankcase on boost that forced oil pas the seal. It is extremely difficult to actually blow out a rear main seal on most turbos. The piston ring doesn't actually spin with the rotating assembly, so it virtually does not wear. It stays stationary on the bore of the CHRA, and the Only time it does wear is when the turbine/shaft gets so hot that it A) collapses the spring tension in the piston ring, allowing for oil to seep out or B) the shaft gets so hot that the ring starts to spin, and when that happens it toasts the CHRA as well.

I was just joking with the Garrett line. You'd be wrong about my HX52 though. It had a toasted turbine wheel and scoring on the shaft when I removed it. I replaced it with a whole new turbine wheel and shaft. Again, can't do that on a Garrett (I guess there is some truth in every joke )

no, YOU can't do that with a Garrett

http://s8.photobucket.com/user/Runtmasterflex/media/http___makeagifcom_media_4-20-2012_QxTCE9.gif.html

Good message from FP on the subject, and I concur completely.

This has been a very popular subject of late with each market pushing the envelope of what these small displacement motors can do. More often than not when we receive these calls people are convinced that their turbo has failed and will need to be repaired and 99% of them are mistaken. We receive at least 1 turbo a month from a person who is having issues with "blown seals" and we have to give him, the good or bad news depending on your outlook, that the turbo is fine and there is a deeper issue at play here.



First and foremost understand that your turbo does not have seals give it a second to sink in. What people refer to as "seals" are actually gas control rings (see the gif posted below for a visual) and these sit in grooves on the turbine shaft and the compressor side seal plate. These act much like piston rings their main function is not to keep oil in, they are in place to keep pressure from the turbine and compressor housings out of the center cartridge of the turbo. Seeing as how these rings ride in metal grooves there is no way for these to become damaged without a significant amount of shaft play. So the rule of thumb here is if your turbo doesn't have excessive shaft play your "seals" are fine.



So you're asking yourself well if the rings haven't gone bad how could oil get out? Well remember how we likened these gas control rings to that of a piston ring? Well just like a piston ring these have small gaps in them and there are a few reasons how oil can be forced through these gaps into the housings. We'll cover them from simplest to the most complicated in that order. Just to get the ball rolling here is a link to a GIF giving you a visual reference.



http://i8.photobucket.com/albums/a20/Ru ... QxTCE9.gif



Your drain tube is not up to par.

What we mean by this is that normally most TC's we sell have about an 1/2" orifice to allow oil to drain out of the bearing housing. This is 100% gravity fed and has no pressure to push it through. So any sort of obstruction can throw the balance off and allow oil to back up inside the bearing housing and seep through the gas control rings. It could be something as simple as a kink, too much RTV, or just inferior tubing that is starting to collapse internally. A less common cause and is usually a problem on cars that weren't originally turbocharged is that the drain flange on the oil pan is below the fill level.



You're feeding the turbo too much.



This particular issue can be a little harder to diagnose as it usually requires a oil pressure gauge metering from the same place the turbo is feeding from. Most of the turbos operate under the assumption that they will see max pressure of 70/80psi. The restrictors we sell for our ball bearing units operate under this understanding as well so if you're running super high oil pressure a different restrictor might be required. If the car is supplying more than that there is a chance you can over run the turbos drain ability and will cause the bearing housing to back up and seep oil out of the gas control rings.



Your PCV system is not up to par.

This is a tricky one and is by far the hardest to diagnose but fixing it is relatively easy. Your stock system is typically a two vacuum system on vacuum pulled through the PCV valve on the valve cover through the manifold and another pulled off the valve cover to the intake of the turbocharger. The one of the PCV valve is used to control PCV during idle and cruising and the other is used under boost. A lot of people making 400+WHP ignore their crankcase or make it worse by removing these vacuum sources and this is a big mistake.



The fact is at stock power and stock motor a lot of people are able to skirt by without any issues and never know that they are leaving power on the table by not sorting it properly. However a lot of people just band aid the issue when they see their dipstick come out they put a vent there. Or they remove the vacuum and run a catch can in line vented through a mesh filter. These do not alleviate crankcase pressure they just give it more room to fill and possibly a little less resistance in certain places. If you were to measure the pressure in the crankcase you would see you still have some and it being in there is not helping you any.



The proper way to run this setup if the stock setup is no longer working for you is to enlarge the diameter of the hoses connecting to your system. Personally on my own car I ran 2 -10 lines via fittings welded to my valve cover to a catch can then another -10 line from the catch can to the intake. This allows for greater volume through the lines and still pulls a vacuum to ensure that all crankcase pressure is being alleviated. Is this over kill for a 400WHP car? Maybe but it guarantees that you'll never have to tinker with the PCV system again.



We also have people convince themselves it's the turbo from swapping from on turbo that does not smoke to one that does. Unless it's the same exact model of turbo charger this is not a valid test. Each turbo has a different bearing housing design some with giant valleys for the oil return like the Journal Bearing Red/Green/Black because they require a lot of oil to be properly lubricated. Some have much smaller cavities like the their ball bearing counter parts because they require much less oil to operate. When talking about this little of pressure 1psi or more it doesn't take much one way or another to either not have an issue or to have an issue with oil being forced out.



So in conclusion if your turbo is smoking and the wheels aren't clanking off the housings it's safe to assume that your issue lies elsewhere.

And thus the reason I generally tell people that I've never had a problem with a smokey turbo that wasn't the result of a crap drain line or something similar.

Great info here guys - my K03 is smoking like a chimney with any kind of load put on it… thought it was the "seals"… time to start digging around for other answers!