Spow

A couple of weeks ago I started the car in the morning. It had been sat for 12 hrs. I was greeted by a big cloud of white smoke. A week later it happened again & now its started to become more frequent. This culmunated this evening leaving a huge cloude of white smoke while leaving a public house (plenty of witnesses - not cool).
My theory is that oil is leaking into one or more cylinders when the car is at a stand still.

Any help with a diagnosis would be appreciated.

Cheers
Steve

colo964

Could also be oil sucked into the intake. I had that a few months ago. I just took one half of the intake manifold off and drained about 1/3 pint of oil from it. Then ran the exhaust clean. Scary, but saved me from buying a rebuild.

If your engine cranks smoothly at the pulley, I suspect that intake before leaky rings.

Heirsh

Are you letting it idle for a while before you shut it off?

dfinnegan

What's a while? . . . 30 secs?

Spow

Colo964,
I will try & check the manifold today. How does the oil get in there?

I dont suspect the rings as its had a bottom end rebuild 20k miles ago. (Polished crank, new bearing & rings etc. I thought the oil might be getting into the cylinder/s thru a valve seat or seal.

Fired it up this morning & it was fine.

Heirsh,
Never let it idle before turning off. What is the benifit of doing this?

Cheers
Steve

Sal 965

Sound like you car needs a good run

How about the Wales Run -

https://rennlist.com/forums/showthre...ighlight=wales

Heirsh

Yeah 30 secs seems to be more than needed for mine dfinnegan.

Its a boxer engine, so if you just shut it off from running it is likely to have oil in the crankcase that will seep past the rings if it sits. I can stop for gas and then turn mine back on without any smoke. If, however, I let it sit for say 6 hrs or so it will smoke everytime (if I don't let it idle a bit before shutting it off).

You are just trying to let all the extra oil drip down into the crankcase and let the pump get it out of there.

dfinnegan

Heirsh, thanks. I have been curious about how long folks idle before shutoff for a while now. I agree that it makes a difference. I don't always think to do this and do sometimes get a bit of white smoke on start up. Other times I don't. I expect it is related to the idle time before shutoff.

Steve, one way the oil can get into the intakes is if the oil is overfilled. The breather hose dumps back into the intakes. This is a common occurance due to the requirements for checking the level when hot (good and hot) and running. I've had a well respected shop overfill mine.

Cheers,
Dave

kurquhart

I recently had large clouds of white smoke after sitting. Mine turned out to be power steering fluid dripping onto the headers. Tightened some loose bolts and the problem went away.

jeffnudd

Wait a sec.

Think i would check the dipstick first to see if the engine has been overfilled with oil. If it has then you will have to empty your inlets :-(

jeffnudd

Talking of not cool i am greatful for the minute that the Porsche is running good, not sure if anyone has broken down yet but i wouldnt mind finding out how embarresed we feel if we did :-(

I have never seen a broken down Porsche at the side of the road :-) YET.

Indycam

I saw a 928 on sand island , honolulu , slowly being striped . Up on blocks , glass all broken , parts missing ....
I thought somethings wrong with the world when a super can can be so abused .

jimq

I broke down on a saturday afternoon in the middle of COSTCO gas station at the busiest time of day. Turns out it was a DME relay which I had stored safely at home Flat bed trip home and all was well with the world.

Spow

Sal 965,
A couple of weeks ago I went to Scotland & did 1600 miles in 4 days. That was a pretty good run. As regards the N Wales run this Sunday, I'm well up for it. I've been working away for the past couple of years & have not been around to attend such a run thru the hills. It would be nice to actually meet other owners.

Jeffnudd,
I am hoping that I've over filled. A couple of weeks ago I topped the oil up with 2 litres. Seems to coincide approx with the start of the white smoke phenomenom. The oil level guage has always given a low indication aprox (1/3) but gradually went into the red. I regularly checked the dip stick but that didnt indicate much change. Oil pressure seemed ok. Anyhow I decided to experiment & put some oil in to see if it would affect the guage indication. I put in about 2 litres in half litre slugs checking the dipstick after each slug. The gauge did not indicate an increment & there was about +3/16" indication on the dipstick. The dipstick is approx 3/4" between top & bottom marks. The level on the dipstick is still within 3/16" of the top mark so I reconed the oil level was 3/4 full. Now the funny things is that since I've owned the car I've always wondered about the dip stick. Other cars I've owned have had low & high levels clearly indicated whereas in this case it is not so. At the end of the dipstick there is a flat that is approx an inch followed by a 180 deg twist approx 3/8" followed by 3/4" flat of which I assumed the top of that flat was the top level?? I've looked in the drivers manual & Adrians book but cannot find an actual diagram of the dipstick.

Been out in the car a couple of times today. Still got a couple of plumes of white smoke on start up but nowhere near as bad as had happened on previous occassions.

Anyhow perhaps I'm the dipstick.

Cheers
Steve

JasonAndreas

Photo courtesy of Marc Shaw