Holy Smokes!

[StephanSloan]

Hello friends-
2001 986 Base with 62,000 miles.
On Sunday I did an oil change. Lucky to have a shop near by where I can rent a bay with a 4 post lift so that was the easy part.
The car is new to me so I used Mobil 1 5w40 as it was locally available. New filter, o-ring, plug and crush washer from Pelican.
After the oil change the car ran great - no leaks and not overfilled (I have a dipstick as well as the sensor).
I spent some time fussing with the top as the back plastic window is dying and I was trying to tape things up to get by until I can do a full new top. I believe I had the key on -engine off for several minutes and may have reset the fuel computer? At the next start I got a big plume of gray smoke at start-up and now get huge plumes of gray smoke if I get the transmission to kick down and run the RPM up.
Drove the car home to put it away until I get things sorted. On the way drove carefully and at low RPM.
I took a right turn at a green traffic light and left a fully opaque cloud of smoke! I remain incredulous that the engine could produce that much smoke without total failure.
There are no signs of leaks and I did not go into the engine bay at the time of the oil change.
Did I use the wrong oil? Did the AOS just happen to let go after the oil change?
I did get a check engine light with O2 sensor codes (P1128 and P1130)
Any help is appreciated.

[tcora]

Time for a new AOS. Based on what I’ve read recently, buy Porsche branded only, as the aftermarket stuff doesn’t seem to have the longevity.

At this point, I be concerned that you have significant oil in the intake tract (for sure) and the cylinders (likely). I would suggest that you not run the engine at all until you’ve pulled the spark plugs and spun the engine over to clear the cylinders. There is danger of hydro locking it.

[Platinum5150]

Interesting that it was fine before the oil change. Are you sure you didn't overfill the oil?

[StephanSloan]

Oil level was fine - I have a dipstick and the sensor was in the safe range and consistent with the dipstick.


Replacing the AOS was among the least fun jobs I have done - anywhere or anytime and I had a full garage with lift to work in. I cleaned the entire intake as it was soaked with oil. The intake manifolds had low spots where oil pooled. If I had not cleaned the intake out I might still be smoking.
This little clip with the new AOS was an excellent investment as squeezing that hose clamp.


As it turned out the smoking stopped almost instantly. Very subjectively the throttle response seemed crisper and low RPM response seemed stronger.

Onward.