turbo seal leaking oil?

[nicknorth11]

i have searched now for about an hour and no situation like mine.

important info:
i have a gt28rs dual ball bearing turbo with about 6k miles on it. stroked 7 bolt with same mileage. balance shafts removed and high volume oil pump.

situation:
after i boost, doesn't matter what psi, and only after i boost, smoke will rise from under the turbo. i have re-rtv'd the oil return line and can't think of any other possibilities other than my turbo seal.

question (s):
do you guys have any other ideas?
if it is the turbo seal, can i fix it myself or do i have to send it out?
is there any other advice of what i should do to avoid future problems?

thanks!

 

[Stapl3]

You have a dual ball bearing turbo with an aftermarket high volume oil pump and no balance shafts. I'm surprised it didn't fail eariler to be honest.

 

[nicknorth11]

is there another option for oil feed that will reduce pressure? (i'm assuming this is what you meant....too much pressure for a ball bearing turbo). i have read that they will perform better with less oil pressure, but nothing about actually ruining them. any other opinions or thoughts? also, still wondering if i can fix it myself or if it has to be sent out. thanks.

 

[nicknorth11]

are you guys stumped or just not interested? let's hear some ideas, i need to fix this thing and make sure it doesn't happen again.

 

[oldman]

are you guys stumped or just not interested? let's hear some ideas, i need to fix this thing and make sure it doesn't happen again.

Please don't bump your thread again.

Are you feeding from the filter housing or the head? BB turbos do not like high oil volume/pressure and should be fed from the head especially with high volume oil pump and BS removed. Unlike an oil cooled turbos, BB turbo is water cooled and oil is only used to lubricate the bearings.

Why do people say it's not good to get oil feed for the turbo off the cylinder head? Should I use a filter on my oil supply line to my turbo?
There are plenty of people who have oiled their turbo off the head and not had any problems, there are just as many if not more that have done it and had recurring turbo failure that was only vaguely described by the repair shop as "poor lubrication".
Oil pressure in the cylinder head on a stock 4G63 engine can be less than 5psi at times, while this may be enough oil for a factory 14b, T25 or even 20g it isn't enough to feed the high volume oil passages of the modified thrust setup in your FPGreen or FPRed model turbo. The Garrett severe duty 360 thrust setups also have an increased appetite for lubrication. Think twice before feeding either of these type turbos from the head.

Remember that you aren't just trying to keep some oil on the bearing, you are trying to float one piece of metal above another piece of metal on a pressurized film of oil, and at the same time keep the whole mess cool enough not to melt. A constant high volume stream of oil does just that, a measly trickle will send you back to the turbo shop.

One exception to this is the Ballistic Concepts Ball Bearing CHRA from Garrett. These turbochargers are totally different internally. Their operation is actually impeded by too much oil. It is fine to supply these turbos with oil from the head. In fact the oil line we offer comes from the head and features a .8mm orifice to restrict the oil flow to the turbo . These turbos require water cooling in the absence of the typical high volume of oil that would normally provide stable temperatures.

As far as filters go, you're damned if you do and you're damned if you don't. You shouldn't need one in your oil line. Failures occur due to dirt/grit in the oil making it into the turbocharger. Failures also occur due to plugged filters. We have seen it both ways. If you are going to use a filter, check it often. The most important thing you can do to avoid oil contamination of you turbo is to THUROUGHLY wash everything more than once before assembling your engine. Avoid sandblasting anything that goes inside or onto the engine. Specifically avoid sandblasting your valve cover. If you suspect that the machine shop that did your valve job sandblasted your head then make sure you remove the 4 plugs from each end of the head that cover the ends of the oil gallies and wash the gallies out with HOT SOAPY WATER. If you do this you will be amazed at what comes out of your beautifully machined freshly rebuilt head.

If you think all that is a bunch of crap, at least spin the engine over to prime the oil system without the turbo attached so that anything in the gallies has a chance to flush out instead of flush into your new turbo.

 

[nicknorth11]

i wanted to end this thread with some extremely useful info. that i found by reading and making some calls. hopefully it saves some of you some time.

this stuff is in another thread that i posted, but again, i wanted to put it here for convenience.

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i was in a quandry about an oil leak that i feared originated from my turbo. when i posted this along with more detailed information, people agreed that the most probable idea was a bad seal. after talking to slowboyracing.com, i now know that BALL BEARING TURBOS DO NOT HAVE SEALS! my problem was simply too much oil pressure, which is easily remidied. i don't have to "fix" my turbo though. this would explain why nobody had posted about blown turbo seals on ball bearing turbos. too much oill pressure hinders performance, but does not actually harm the turbo.

the pressure can be reduced by:

an ss oil feed line that comes from the head instead of the stock located oil filter housing. along with this method of reducing pressure, there are restricters. (10x1.25 banjo bolts with an .8mm inner hole also work to restrict oil pressure).

on in-line oil filters for this method of lubrication:

there is a higher potential for debrit when running off of the head, but mainly this debrit is from building the engine. in my case, i will not run a filter because i have around 6-7k on my engine. also, filters can clog, causing a complete restriction of oil. (this is not that uncommon). running a filter is a better option if planning on regularly checking and replacing it, but if you're lazy, like me, it will probably be your turbos downfall.

to anyone reading this, if you've learned something here, click my scale and hook me up with some rep. points.