Carl Byck

O'k, My buddy, and turbo aficianado tells me it is possible to have enough oil pressure to bypass the oil seal on a journal bearing turbo w/out damaging the seal... In other words, he is stating that he has pushed oil through the seal, and caused huge amounts of smoke, later, by reducing the oil pressure, he has eliminated the problem. He goes on to say, that he thinks my turbo is ok, and that I just need the proper restrictor(on this we agree). So, anyone else bypass the oil seal to the tune of ~1/4 cup on the cold side, and a 1/2 cup on the hot side, and not need a rebuild? LMK, Carl

hIGGI

iTrader: (7)

ever got splash of oil from BOV ?

Carl Byck

???HUH?

Carl Byck

I guess not, are you saying possible?

hIGGI

iTrader: (7)

yes, possible....wrong oilpan venting could lead into it
oil will get thru front seals into compressor, then into intercooler and first way out is thru BOV....

J9R8

Yes, it is very possible, and when the pressure (or drain restriction) is removed the turbo will be totally happy. I've experienced this on numerous turbos, with no long term effects.

There are two cases. Case one is if the seal is totally blown, and if you reduce the excess pressure and the turbo continues to smoke or leak oil into the charge pipes. Case two, well that is described above.

What turbo are you running? 1/4 cup is not bad... I've seen near 2 qts! drain out of an intercooler, and the turbo was ok after

Carl Byck

Turbo is a new Precision PT67 P trim .81. Here is an exerpt from some PMs between me, and Dave my tuner;


i can't really say for total sure. but since you do have some front to back shaft play, i'd say the turbo is bunk. keep in mind i'm not a professional turbo guy, but i've blown enough of them up to have a good idea of what to look for when they go.

dave[/QUOTE]

Intersting, I talked to two turbo guys, Our local Truck turbo repair shop, and a freind of mine who excels at blowing up turbos. You would like him, he blows into the oil inlet, and tells you by the burbling soud of the oil if your seals are good. He also, bases proper oil delivery from the motor off of how many seconds it takes your oil feed to fill a Big Gulp Anyway, we are going to clean it up, and try refiring it if Precision agrees with these two guys. The sorry part is that if it is not blown, we could have cleaned it up, and sent you home a day later. One other thing my turbo buddy said, was that the "U" in the drain line is a big NO NO. He said a 90* is fine, but the volume of oil in a foot of -10 line is enough to overload the seal. Good stuff, if it's true. So, to recap, Alan thinks the control rings are toast, you think the turbo is toast, Precision agrees w/you, and my bud, and the local turbo place say, clean it up, and it'll be fine. One other note, the turbo guy locally said that the seals require a certain amount of coked oil for the carbon seals to seal properly. So kinda like a rotary, breaking in a turbo(never heard of that before), will occur much faster with Dino oil(your favorite) ****, Just when I knew everything.... Carl


So I will be changing my drain a bit, restricting the oil inlet to .125( a little larger than what has been recomended, but I have it already, and it worked well with my other Garrett.

My oil drain was a -10 with a "J" shape to it. straight down out of the turbo, into the bottom of the "J", and thena 45* into the engine block. it will go back to straight down, with a 45* into the motor. The bottom of the "J" is supposed to be part of the problem do to the oil not draining by gravity out of it.

twokrx7

iTrader: (1)

Would agree that the J may be your problem, the oil drain should be setup to gravity drain into the case. Knowing this now, you may not need to restrict the supply oil very much. If you do, do not go small on the restristor, go at least 0.1".

Knowing that this is not your first turbo, did you ever run this configuration before and get away with it?