oil inside intake hose !!!

[carreraSC]

I recently changed all of the old hoses that run from my supercharger to the intake and notice a small crack on one of them. There was also a little bit of oil smeared around the cracked area. Can someone tell me if this means that my SN unit is somehow spewing oil into my engine? If so, is this a sign that the seals are worn out, or maybe a sign of something more significant as far as internal damage???

Any help or pointer is greatly appreciated.

Thank you

Stephan

[speedytang]

Oil or Transmission Fluid?

[carreraSC]

I am assuming trans fluid from the blower since the only way to that hose is from the air filter through the blower and the MAF. I found a small amount "smear" of oil in the hose that connects the MAF to the metal pipe that goes to the intake and throttle body. I doubt that it is motor oil !!

Any thoughs on what is going on here,....

Thanks

Stephan

[zray]

is the PCV anywhere close to the found oil ?

Z.

[Michael]

I am assuming trans fluid from the blower since the only way to that hose is from the air filter through the blower and the MAF.

You can't assume that it's transmission fluid just because the hose is connected to the blower. Since the hose travels from the blower to the intake, as per zray's question, it could very well be engine oil from the crankcase via the PCV system.

What color is the fluid? If it's brownish, it's probably engine oil. If it's redish, then it's transmission fluid. Once you know that for certain, then it'll be easier to start diagnosing the problem. If you can't determine the color, then try cleaning out the hose completely, reinstalling it, drive the car for a bit, then check the hose again. If it's a severe problem, that oily film will be present after a short time; if not, then you may have to drive the car a bit more. That should help determine what kind of fluid it is.

If it is transmission fluid for sure, then a seal within the blower may be on the brink of letting go. Obviously my advice would be to replace the seal(s) ASAP as to avoid catastrophic failure (of the seal). You can buy replacement seals from Paradise Wheels or CUNDN Racing; if you do a search on the forum here, you should find an exploded view of the SN blower, which will show the location of the seals.

If it is engine oil, then I'd start by first checking the oil level to ensure that the pan isn't overfilled. Then check the PCV system, followed by a compression and leak-down test of the engine. That oily film could be caused by anything from having too much oil in the crankcase (it's happened to me), to a bad $2 PCV valve (old, stuck closed) or a plugged hose, to excessive cylinder blow-by (worn piston rings).

Hope that helps.

[carreraSC]

Thanks for all the help guys.

The reason I am assuming it's noit engine oil is that the stainless steel pipe that connect to the intake (throttle body) and to the rubber boot connector hose, is very clean. The oil I found was in the cracked coupler between the MAF and the blower. Does this makes more sense,...

And yes, I did check for engine overfill, rule that one out, perhaps bad ring, I will initiate leak down test soon to figure it out.

As for the blower seals are they difficult to change (front and rear)???

Thanks

Stephan

[Michael]

And yes, I did check for engine overfill, rule that one out, perhaps bad ring, I will initiate leak down test soon to figure it out.

If it is transmission fluid from the blower, than the leak down test probably won't reveal anything, but it's good to do anyway just to rule out the possibility of worn rings/excessive blow-by.

As for the blower seals are they difficult to change (front and rear)???

Unfortunately, I've never replaced the seals on an SN. Hopefully one of the members here can lend more assistance in that regard.

I can tell you that dismantling an SN unit is not difficult at all. Once you remove all the fasteners around the perimeter of the outer case, there's not much inside. It's the reassembly that's the tricky part.

Run a search on the forum here - I'm sure you'll find photos of disassembly and reassembly of an SN, which will give you a better idea of what to expect.

[speedytang]

It is usually the rear seal which is a simple install. Split the case and remove the impeller shaft and impeller. Pull the seal and replace. It is about a 20 minute job. All the adjustments are kept so just put it back together.

[carreraSC]

I've heard that everytime you split the casing and remove the empellar bolt/shaft, you need to replace it with a new one !! Is there any truth to that?

Thanks

Stephan

[speedytang]

I never have in the 20 years I have owned these units. Just use lock-tite on the impeller bolt.