Pat-Man

iTrader: (3)

Picked up a 98 Z28 last weekend. Has a built 408 and a T76 turbo. Well, I've been going over little things on the car and seeing what I need to get it to where I want it. Mounted up the bumper support to take some measurements (moving FMIC off radiator). I then decided to take off my cold pipes from the turbo outlet to the FMIC. Well, I find oil pooled in the pipes. I'm new to the turbo field, but I know this can't be good. Are my seals in the turbo possibly leaking? Does this just require a rebuild? Thanks for any advice or tips guys.

Straight pipe from turbo outlet


Bend before going up to intercooler inlet (I think the oil may have been to heavy to travel up this pipe. Most of the oil was pooled here)


Turbo outlet connection (this pipe connected directly to the turbo outlet)


And the mouth of the turbo outlet (you can barely see the .70 AR marking)


Sorry some of them are blurry. Cold in the garage.

- Patrick

z28berryhill

iTrader: (26)

heppend in my brothers ***** u may need new seals in the turbo..it requires a rebuild but he ran like that for maybe 5000 miles...just burned some oil and ran richer...coudl be somthing else though not sure

Pat-Man

iTrader: (3)

Thanks man...under the car now trying to figure out how to get the turbo out. Man...what a mess.

350SS

iTrader: (38)

I had a simiar issue, although it was with a new turbo and was more severe on the turbine side...

https://ls1tech.com/forums/forced-induction/848155-once-oil-passes-turbo-seal-need-replaced.html

I'm running a restrictor now and seems like it's helping so far.

stevied916

iTrader: (30)

make sure its the right size restrictor and sometimes it can just be blow by, not the turbo

Pat-Man

iTrader: (3)

I read through your thread and I'm wondering if its because my turbo is seeing 40psi at idle. Also, the turbo is mounted low towards the bottom of the oil pan. Wonder if it might be having problems returning oil to the pan?

Do you have some instructions on installing a restrictor in the oil line?

ninetres

iTrader: (35)

If it doesn't have a seperate drain pump then the turbo needs to be moved higher than the pan.

And did I read your turbo is seeing 40psi at idle???? Eek. What head gasket you runnin? lol jk

Pat-Man

iTrader: (3)

40psi oil pressure

I'll take a few shots of the oil drain line that taps into the bottom of the oil pan. Thanks for the info.

JPATI

iTrader: (1)

My budddies car(101mm) done the same thing with a New turbonetics and a precision unit. Get the book maximum boost(corky bell). it talks about minimum oil psi to the turbo. it doesn't take much. We first put a weldon oil pump for the drain(thought maybe that was the problem).NOPE wasn't it. We made a T fitting and installed a oil psi gauge on the turbo. we had between 40-60 at idle(warmed up) and more than that at WOT. We installed a N20 jet to restrict it. I want to say .025-.030 with regular oil 10/30 and had 25-30psi under full load(it will drop from idle-load). We change the oil to Royal Purple(10/30) and we had to increase the jet size to .055-.061 to maintain the 25-30 psi underload. He has been running this way for 2 years now..no problems
No more turbo smoke, no more oil in the pipes and we took the weldon pump back off.
Hope this helps

Pat-Man

iTrader: (3)

Are you all placing the nitrous jet in the oil return line? Does it just sit in front of the tap nipple? Thanks everyone.

o2ws8

iTrader: (1)

dude are you here in waco?

JPATI

iTrader: (1)

the jet is placed in the oil feed line going into the turbo(bascially the turbo is getting to much oil and it is blowing oil past the seals). We used some N2O fittingsScrew the fitting into the turbo, then place the jet in the fitting, then screw the oil feed line onto it. Just like changing jets on a N2O nozzle. The drain should be large(-10 or bigger) and nothing(no jets or anything) goes into the drain. The drain is suppose to be free flowing and easy as possible for the oil to return to the pan. You want the drain straight up and down if possible so it drains easy.

Pat-Man

iTrader: (3)

Yes sir, I'm jumpcable on NTAC.

Pat-Man

iTrader: (3)

Is this drain line sufficient? Its a 90 degree fitting and it slopes slightly downwards to the bottom of the oil pan where another 90 degree fitting is installed.

o2ws8

iTrader: (1)

you got pics of the whole car or motor?

Pat-Man

iTrader: (3)

Motor

6.0L Iron Block, 408cid, forged, stock heads and cam

Just pulled out air system and egr. Working on redoing the intercooler setup and piping. You can see the top of the intercooler right below the air lid. Moving it off of the radiator to the bumper support. Has a blown transmission (3 -4 clutch packs). Body is just a plain ol stock looking NBM 98 Z28 on jack stands right now.

JPATI

iTrader: (1)

If it was mine, I would get rid of the pipe fitting(brass) 90's. If you have to use a 90..then use a full flow(AN) type. i would atleast take the 90 that is in the middle of the hose off. Just use the 90 that screws into the oil pan if you have to. How big is that return hose?

Pat-Man

iTrader: (3)

Thanks JPati. Its actually only using two 90 degree fittings. One on the oil pan and the other goes directly in the turbo. I'd say the line is a good inch or so large.

Reject

iTrader: (24)

the ring worm clamps, on the piping?

JPATI

iTrader: (1)

I would get rid of the 90 out of the turbo. Let it come straight down out of the turbo and go straight to your 90 on the oil pan. If you can get rid of both 90's that would be great.

You need to get your oil psi at the turbo(feed) around 30-35psi under boost. Once you do that, your drain might be ok. Check your oil psi with the engine fully warmed up. I bet it is high.