rayqblue94

Hi guys, this is my first post to Rennlist so please excuse any lapse in protocol. I have a 928 '94 gts auto supercharged with a Murf kit.
I have noticed a small amount of engine oil? in the inlet duct to the supercharger and also around the blow off valve(ie: both sides of supercharger). I assume there is a leak from somewhere in the supercharger itself. After 3 months there would only be about 10 ml oil in total so it's not gushing out.
My question is
1. is this normal?
2. if not, where is the leak coming from?
3. how to fix it?
Thanks for any suggestions
Ray Barton
94 gts
Ipswich
Australia

UNTS1

Sorry I cant help you with your problem, but I notice your from Australia, where did you get your 928 supercharged from? Do they also turbo 928s?

Bill Ball

I'm guessing here... those who are very familiar with this system will jump in soon.

The Vortech blowers have bearings fed with engine oil. It could be a leak in a bearing seal.

John Speake

Welcome to Rennlist Ray !! :-)

daveo90s4

Hi Ray,

Yes indeed welcome, as John Speake says.

Gee I wish I were there to help sort this out with you!

I assume that you've posed this same question to the manufacturers of your supercharger?

Dave O
90 S4
Dubai

rayqblue94

Thanks for the feedback Guys,
Glad I managed to get posted at last.
UNTS1 - The kit is from US - Murf(Vortech) and locally installed. It seems for 928s' supercharging is more popular than turbocharging -probably due to heat issues.
Bill Ball - thanks for the lead Bill - I suspected there would have to be some point where the oil feed met the impeller shaft but wasn't sure if it would be a gasket, bush or bearing or how to access it - I guess it's a call to Vortech for help.
DaveO and John D S - Hi , Yeah I finally got the courage to wade in the big pond - Tim showed me how the system worked. Thanks for the welcome and hoping all is well with you.
Cheers
Ray Barton
94gts
Ipswich
Australia

Joe Dyer

Hi Ray,

I had the same problem, but only noticed when on the track and using lots of WOT. My valve cover breathing was plumbed back into the SC inlet. When my oil tank filled, it flowed into the SC intake and pressurized, spitting oil out the blow-off valve.... a real mess. Street driving and autocross was fine. Anyway, I've plumbed the line into a second tank that I can drain when it fills up.

I don't know if you have blow-by gases plumbed into the SC intake, but it's a common way to close the system.

Enjoy the SC!
Joe

rayqblue94

Hi Joe,

I took a refresher course on Supercharging, It seems the "mechanic" who installed my SC. lost the tensioner spring ,then tightened the belt to industrial strength also wound up the blow off valve adjustment(to annoy WRX's) so it would make a noise(blow back through pump).
I adjusted the belt tension and BOV and waiting to see results - I haven't seen any 'loose' oil since but waiting to see if this is a fix.

I think it may have been a combination of back pressure and over tension on the SC bearing, blowing oil through the bearing seal as Bill Ball suggested

My breather set up from Murf was hose open to air. I fitted a cloth filter inside a perforated catch can to eliminate oil fume/smoke at idle - all works well.

thanks for your suggestions on this problem.

Ray Barton
94 GTS k