dcg9381

I have some darn issue where I seem to be destroying hot side bearings on my t3 turbos. Bearing looks mildly coked, generally out of spec. Cause the compressor to get wobbly and will lead to something nasty of course...

My EGTs at cruise are 1100-1350, as measured directly after the exhaust port on #4.

I'm trying to decide if I've got an oil problem of some sort or I'm running too hot an EGT....

I'd love suggestions.

Ogubudiah

are you using shitty jy turbos?

do you have a restrictor in your oil line?

biscuit

Dumb suggestion... Has the turbo been balanced?

accordepicenter

you are def looking at some kind of oil flow deficiency, the oil should keep the hot side relatively cool enough not to burn off the oil and coke up bad, if you have a restrictor, either modify or remove it to increase flow. It is also possible that your oil feed line is partially plugged

2G6

It's definitely an oil starvation problem. Are you using any RTV sealant or something of that nature on your feed line? I can't tell you how many turbos I've rebuilt that have the oil passage to the thrust bearing clogged with some sort of sealant and have destroyed themselves. Hvae you taken your turbo apart and inspected it? The balance question was definitely valid. Make sure your feedline is good too. Also, if you're using a fitting to attach the feedline, make sure the hole in it is big enough. I am running a function7 T3 fitting for my turbo and the goddamn hole that the oil feeds into the center section via was way too small. I had to open it up a little bit. Good luck on finding your issue man. Your EGT's are fine, and I honestly wouldn't pay too much attention to them.

dcg9381

Thanks for the replies, guys. These are all Garrett turbos (I've baked more than one). No junk. Dynamically balanced. New turbos, so it's getting expensive.
They last about 200 miles.
Feed is a 4AN line, it does have a restrictor in-line, but I've opened the restrictor to slighly larger than 1/8th in. I'll open it up completely.
It also has a Forced Performance FP4AN Filter in line, again, opened up a little more than the recommended .125":
http://linux.forcedperformance.net/m...de=FP4ANFilter


Is there a good way to measure volume or should I measure oil pressure at the turbo with a given diameter feed?
I have decent oil flow (out of the 4AN line) under cranking RPM.

Here's the turbo before this one (that just started to go, it'll be shutdown and repaired) - coking on center section at about 250 miles:

http://lakebox.dnsalias.com/photos/1...turborbld8.jpg


Can the oil drail be too big?

Smith-02

you run a wide open line, then close it down until it JUST stops smoking, or a little smoke. burning a little oil outside of engine combustion is no problem, just dont forget that youre losing some out the turbo :1

dcg9381

Inlet and outlet are function 7 fittings. Inlet has been opened up beyond .125. Outlet is huge.

Smith-02

no inlet restriction?

what weight oil you using?

considered an elec oil pump for turbo only?

dcg9381

Some inlet restriction. I believe the function 7 fitting has a 1mm hole standard. I drilled it out a little wider than .125" - I can go wider still.

My filter had some restricion in it, it's a fairly small filter and the element was covered. Going to use a standard oil filter via a remote oil filter kit.

Haven't consiidered an electric pump, no... 10-30W oil. Dino for now as I'm under 1k miles.