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Post AOS replacement smoke


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A few days ago, I had the pleasure of clearing traffic with the MI6 smoke screen from my failing Air Oil Separator. After towing the car home and installing a new AOS, I am back in business.... sort of..

Here are the details..

Pre-Smoke screen...

2001 986 (recently acquired)

Recently experienced standard codes indicating MAF problems. Before replacing the MAF, the motor was not running smoothly. Once the MAF was replaced, the motor ran smooth, BUT did have a bit of an erratic idle. No CEL codes though.

A few days later, I noticed a bit of smoke coming out of the tailpipe on startup. Knowing this is not uncommon with the Boxster, I decided to wait until the weekend in order to investigate the idle issue.

As luck would have it, during the weekend, the AOS failed, creating the typical smoke screen. This is the same smoke that I have seen in a previously owned 986.

Once the smoke started pouring out, I shut the car off within 20 seconds. In the 10 minutes of driving before the incident, there were no indications of engine problems (power was ok, acceleration ok, etc).

After replacing the AOS and starting the car, loads of smoke came out and within 10 minutes, the amount of smoke coming out was dramatically reduced. I did notice that the idle problem is gone (Yay). If I take off the oil filler cap, I can hear suction and then the idle changes. This erratic idle immediately goes away when the cap is reinstalled.

Here's the question...

Now that the AOS has been replaced and the idle looks good, how long should I expect the smoke to come out of the exhaust. Is there a chance that another problem exists and I should not run the car? I've read that it may take around 100 miles of driving for the smoke to go away. I'm hesitant to drive the car in rush hour traffic until the issues have been cleared. Any comment will be greatly appreciated.

Kevin

01 986 Azure Blue

Miami, Florida

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Nope!

Take her for a good thrashing and by the time you get back from a good 40-75 mile drive I'm sure the smoke will be cleared up.

In addition. If you missed a connection the car would probably not run normally. For example the idle might be very rough because of an intake leak.

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  • 2 weeks later...

Well, now that I'm back from travels, it's time to finish the project.

Here's what I have done so far.

Replaced the AOS and the tube that runs from the AOS to the intake.

In the process, cleaned the intake (where I found quite a bit of oil).

Changed the oil and did not see any sign of coolant.

Checked the coolant.. no sign of oil.

Here are my observations, some of which concern me..

The car seems to run fine. Idle is ok, surges just a little bit now an then, but nothing like before the AOS failed.

If I take the oil cap off when the car is running, then the idle becomes rough (Demonstrating the effect of a vacuum leak)

If I let the car idle, then the smoke becomes less and less, until not easily noticeable.

As RPM goes up, more smoke comes out. This makes sense as the residual oil is burned off.

A few drops of what seems like water come out of the tailpipe, every minute or so. (Yes, I am aware that it's not abnormal for a few drops to come out of an exhaust pipe)

I've been running the car around the block, in an attempt to burn off the oil. To do it well, I could run the car up I-95, but I am concerned about getting pulled over by the police and also getting stuck if something else is amiss.

Here's a link to a photo of the current amount of smoke after a trip around the block.

http://i42.tinypic.com/32znoy8.jpg

With all said, does the smoke look like it is being produced from oil or coolant?

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Everything in your post sounds normal.

Really tough to say from that pic, but that doesn't look very significant to me. When my AOS went out there was a lot more smoke.

Do you have any back roads you can take it for a good drive, or perhaps late at night when the roads are clear? Around the block isn't going to do much...

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