Interesting dilemma

[Hayabusa]

Recently with my 930 I am noticing that going down hill and maybe at a more accelerated rate of speed when I down shift or decelerate in second semi aggressively I notice, (at first it was) a puff of blue/white smoke. I can do this non-aggressively, just putting around and nothing happens.

I thought it was my left rear tire locking up, but a friend who was trailing me one day confirmed that it wasn't my tire, but in fact, it was coming from the lower left engine area.

So, today coming down the mild 5% grade and it gave way and nothing except stopping would cause it to cease.

I was thinking valve guides, but it all came up all of a sudden and doesn't occur in any other instance other than hard, at speed (3-4k) deceleration.

Thoughts on this? Thanks!

[Hayabusa]

Not one single thought from this vastly experienced group?

[jbrinkley]

did you take a look at the turbo, and the drain line?

[Hayabusa]

I do remember that thread where the drain line was melting down on the turbo. I will look at that this morning.

Any idea why, if that is it, why it would do that on decel?

[DW SD]

Chris,
Two ideas:
1. Something related to strong engine vacuum as would be valve guides. Is your friend sure it is not coming from the exhaust itself?
How much oil do you consume?

2. Or maybe you have an oil leak exacerbated by deceleration (oil being thrown forward)?

Doug

[Hayabusa]

Yeah, Doug, my friend was a few car lengths back when he saw the plumb emit.

I thought about the 'oil being thrown' forward bit, but this problem just came on so I haven't ever had it do this on accelerated decel before.

[Hayabusa]

I'll have to have him set up behind me again to see if it was the exhaust.

[RarlyL8]

It does sound like valve guides. If so it should go away when you push in the clutch.

[WERK I]

Check your intake tract from the CIS flapper plate all the way to the throttle body. If you find oil deposits below the flapper plate, you are sucking oil vapors from the oil tank. That is, if you have a breather hose going from your oil tank to the back side of the air filter.

[Hayabusa]

Originally Posted by WERK-I

Check your intake tract from the CIS flapper plate all the way to the throttle body. If you find oil deposits below the flapper plate, you are sucking oil vapors from the oil tank. That is, if you have a breather hose going from your oil tank to the back side of the air filter.

Good tip, Dave. I'm having it put up on the rack this coming week. Oil tank does look soaked. Not happy with this.

Thanks to all that jumped in here! I do appreciate you all!

[jay71]

Would a soaked oil tank and oil getting into the breather hose behind the air filter simply be symptoms of too much oil added at last oil change? Not being a smart a** here- I'm asking because I have a new to me 930 with these symptoms (sans the blue/white smoke) and I was wondering if previous owner over filled.

[Hayabusa]

I understand that there is supposed to be a certain amount of oil in the tank,,, just not too much.

Is that right? Don't know if an over-fill would fill that up though.

[WERK I]

Originally Posted by jay71

Would a soaked oil tank and oil getting into the breather hose behind the air filter simply be symptoms of too much oil added at last oil change? Not being a smart a** here- I'm asking because I have a new to me 930 with these symptoms (sans the blue/white smoke) and I was wondering if previous owner over filled.

No, not necessarily. Keep in mind the oil going back into the tank is under pressure and under certain conditions, you can get oil droplets bouncing all over the in side of the tank. The oil breather hose is a vaccuum source........