Oil Overfill
 

A couple of weeks ago I changed the oil/filter in my 2001S in prep for a track day. Change went fine. Filled with 8-8.5 qts of Motul while on the ramps. Started the car drove it off the ramps and checked the oil again. It was a little bit low on the dip stick (as to be expected with an initial fill of 8 qts) so I topped things off with another .5-1.0 qts. Checked the oil and I was at the top of the full mark. Perfect. ready to go to the track. Well first lap coming out of a hard left hander I left a big white smoke screen. Car ran fine but pulled off track obviously. I get back into the pits and check the oil. It is up above the full line (same after checking a few times after letting things sit for about 10 mins).

While in the paddock I borrowed a drain pan and drained about 1 qt of oil off. When I checked the oil level I was just below the full line and I figured all was good. I went out for the next session and the same thing happened in the same place. Big smoke cloud. I assume I still had too much oil in one of the heads that wasn't able to drain off and was too much for the scavenger pump to transfer back.

I did the typical AOS check of running the engine and removing the oil fill cap. There was some vacuum but the cap came off easily. I also scanned for codes and got a misfire on cylinder #2 and an O2 sensor warning. I assumed oil fouling. I drove the car home (on advice for a dealer service manager) and the codes cleared. Car is running fine now. Oil level is 2 ticks below full, no smoke on normal driving, and no oil leaks.

So what I am assuming happened is I filled the oil while on the ramps and then didn't wait long enough for the oil to drain down after I started the car to get it off the ramps before checking again and topping off. Thus I over filled things.

I am hoping that by driving home I burned off residual oil and by letting things set for days that the oil that was probably overwhelming the scavenger pump has drained back to the sump. I am planning on changing out my AOS this weekend preventively, but is there anything else I should be looking into?

Overfill can be bad news for these cars. Hopefully you caught it before it killed your valve seals. Check your level often to make sure you are not losing/burning more oil.

It is easy to overfill the required oil level. Just add a small amount such as a quarter of a pint at a time. Let it settle several hours before putting in any more. Each bar on the oil guage represents a very small amount. If you overfill remove the oil filter housinng and filter as it does not gush out like the drain plug.
Cheers, Guy.

I overfilled before my first track day and got exactly your same symptoms. Drained some out by dropping the oil filter and it hasn't come back in over 5,000 mikes of driving, 3 more track days, 3 autox, and another oil change.

Thanks for the info. I appreciate it. I am hoping I am in the same boat.
Kevin

It was very scary, that's for sure.

Here's my old thread when it happened to me.

http://986forum.com/forums/general-discussions/48301-troubleshooting-sorting-possible-aos-issue-maybe-something-else.html

Steve

I would not mess with a working AOS.
"If it ain't broke, don't fix it"

Save it for when an actual failure has taken place as preemptively fixing things sometimes causes more trouble than it prevents.

In a preemptive AOS replacement what could go wrong:

AOS Cracked vent line to throttle Body.
AOS Cracked vent line #2 which goes ??? around the engine passenger side.
Split AOS Bellows tube
Invisible air leak introduced somewhere in all those pipes.
Improper AOS seal with engine block
skinned knuckles
Your arms are too short to reach stuff.
excessive profanity causing your dog to hide under the bed and the family to leave to visit Grandma in a hurry.
not being able to drive the Boxster till all the above is sorted out.

Just Saying...

Ramps are bad. Your car is major tilted on ramps. Put it up on four jackstands, drain the oil, change filter, put plug back in. Lower car to ground. Fill with oil on level ground.

You need to put oil back in before you can drive off the ramps. This is the problem.

The OP lives in Denver, and Jake Raby has commented that the AOS seldom fails at such altitudes.