RaceCarDriver

last time I drove my 2002 996 C4S was about two days ago. Not a daily driver but gets driven 2 or 3 time a week, about 5k miles a year. Car has 66k miles, owned for the last 4 years (never had any problems).

Drove the car for about 20 spirited minutes at lunch time, a couple of redline shifts, one slight over rev in first gear, first time I ever did that (about 300 rpm past redline). shut it off hot, went back in the office.

came out an hour later, started the car and their was a HUGE cloud of White Smoke on start up. Lasted about 10 seconds, maybe less. Lasted about as long as it took me to notice the smoke, unbuckle seat belt and walk to the exhaust pipes.

Smoke from exhaust pipes looked white not blue.

drove it about 5 minutes, ran fine no smoke. parked it. Started it an hour later, another HUGE white cloud of smooke for about 3 seconds. Shut off car.

waited half hour, started again, white smoke for 2 seconds.

Never had this cloud of smoke happen before. This is not a daily driver but when I've gone a week or so without driving, some times a get a tiny puff of white smoke for a second (condensation) but never like this.

Outside temps were 90 degress and very humid. Water temp was normal. Last oil change was 2 months and 500 miles ago. I did about 2 months ago top off the oil (added a half qrt) for an autocross.

Oil had been full and was full last time I check probably a few weeks/a month ago.

Checked the oil again after this white smoke today and I am two bars low.

Anyone know what this might be?

thank you,

G

Dharn55

Couple of things to check quickly. Is there any trace of coolant in the oil, or oil in the coolant. Look in the coolant reservoir and on the dip stick. If you have contamination this would indicate you might have coolant getting into the cylinders.

Next take off the air box and the throttle body and look for oil in the intake plenum. If the AOS is going bad, and this can be a source of such smoke, you will likely see some oil in the plenum. You can also check the breather tube that runs from the AOS to the plenum, it connects to the plenum on the left side behind the throttle body.

Probably a bad AOS.

uberskier

Sounds like the AOS. I've described the same thing to my indie and that's what he says. Happens sometimes with some spirited driving on the street and about 30-50% of the time after starting up after a DE session.

RaceCarDriver

how much does AOS cost to fix?

I did not see coolant in the oil or oil in the coolant.

Graufuchs

AOS +1

CosmosC4S

You can bet it's the AOS going bad, like everyone said.
The dealer will steal $600-800 from you for a AOS replacement. More labor for Tip than 6spd.

nick49

Hope to hell it's the AOS.

It could be the cheapest thing to repair along these lines. Also hope it's white smoke from burning oil and not steam from coolant leaking into the combustion chamber thru a cracked cylinder liner. This happens all too often and usually ends in a motor replacement.

I wouldn't fret at this point especially if your oil is low and coolant is full. Hoping for the best!

white99c2

Is spirited driving a new phrase. It sounds like most of the time things go wrong when people beat on their cars.

jyoteen

you mean we should drive these cars as if they were made out of fine porcelain?

I don't think i've driven the car in a method OTHER than describing as spirited driving; on and off the track.

white99c2

Dude hitting the red line a couple of times is not smart. After all its how many years old???? It's your car enjoy it the way you see fit, doesn't sound like this is turning out to be much fun. I have one of these cars to and bought one new in 1999. If you're hitting the red line you are driving pretty fast on the street, thats not to smart.

Janusz

"Hitting the red line" is the best part of owning that car. I do it at least few times each day I drive it. My car is 8 yrs old and I will rev it to the red line when its 18 years old if I'll still own it. It is good for the car and it is good for me.

RaceCarDriver

My coolant IS slightly low

RaceCarDriver

just to clarify, one shift slightly over redline (first time I've ever done that), and a few shifts between 6k and 7k (did not hit redline)

chsu74

You will also get this if your oil is overfilled. It sound like the period of the smoking upon start up is getting shorter and shorter. Keep driving it daily for the next several days and see if it goes away. You said there is no sign of coolant in the oil..

ArneeA

???? Maybe we should drive the car like grandma's becase they've got some "age" to it?