FifthGear

Just looking for some feedback from the group, prior to bringing the car in again, and hoping someone might recognize this behavior from their experience so that I have some direction when I speak to the next mechanic.

There is a sweeping-left-turn on-ramp to the highway that I take frequently, and on the occasions where I really pushed it (in throttle and some lateral load) the car would throw a code and the check-engine would come on (of the "keep driving" type). Simple reaction would be to check the code, but it disappears not long after, and even the dealer could not find the history of it, which is weird. This happened 4 times.

I took the car to the track following a dealer inspection, and within 2 laps fire was shooting out the tail pipes (we had walkie-talkies) and my day was done. On site techs feared the worst based on the smoke, at least two cylinders misfiring. Towed the car to the dealer.

Two days later the car is ready and I pick it up after-hours. The bill after all that had been explained, and the test drive? Six spark plugs replaced (no sensors cleaned or anything). When I start it, the car has lost over one litre of oil and the oil level warning goes from yellow to red as I watch. The dealership now closed, and my confidence already lowered, I limp the car home at super low revs and add back the missing litre in my garage. Car stays in the garage a few days. I start her up for the first time, and I get this:



Smoke show extraordinaire. The white smoke clears after a long while of idling (and temp increases to normal levels) and the right exhaust is the last to clear it's smoke. After that, no oil lost, no smoke when I start it, no codes when I drive it. Out of storage for a couple of weeks, I finally pushed it again yesterday after a quick sweeping turn under full throttle, and bingo, check engine again that disappears.

Originally I had told the dealer that the only thing I could think of was a failing AOS and that the car was dumping oil into the intake under both throttle and turning. I'm really hoping it's not scoring, the beginning of a D-chunk, or something like that.

Should I simply go back and straight-up tell them to replace the AOS? After my last experience at the dealer with this, I'm not thrilled at the idea of going back. Locally I have VAG, WeTune, 191 and a few others I can rely on, I just feel like I need to come in with a strong case and hopefully get to "know what I don't know" from here before I have that discussion.

Thanks for any help.

vanlieremead

Which model and engine? What was the reason for the first failure? Plugs?

FifthGear

2017 911 GTS (so a 991.2)

Yes, they said it was the plugs.