Oil leaking from exhaust - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Brian Minson · 08-07-2019, 07:56 PM

I had some time tonight to get under my cheap Porsche Boxster to look and see what could be wrong. I have a video of me buying the car on my Youtube, in which you can see the white smoke (AOS I am sure) and the loud knocking; I was expecting to see a hole in the bottom of the case. However, I found oil leaking out of the exhaust flange on both sides, I just posted a short video of how bad the oil leaking out is.

I tried running a search online for this issue but didn't see much on it. Lots on the white smoke from the AOS, but not oil dripping out from the exhaust flange. My first thought is the plastic spark plug tubes are shot; a new AOS and new spark plug tubes might fix the oil in the exhaust... but could the fact that the exhaust system is bearly holding on be the loud knocking noise?

Ideas?

Here is the link to the video of the oil dripping out.
https://youtu.be/v8YfelE6Pg0

Thanks,

Brian

Fiddlebog · 08-08-2019, 01:49 PM

Get ready for an engine rebuild. That is not the AOS.

maytag · 08-08-2019, 02:16 PM

If the AOS is bad enough, then you could fill the exhaust system with oil being pumped through the motor. Ask me how I know. But you'll notice the motor running rough at that stage.

Here's how my thought-flow would look:

Does it run well, even at High RPM?
Does it blow MORE white smoke or LESS when you rev the motor?
Does it leak MORE oil from the exhaust, or LESS when you rev the motor.
Does the loud knocking go away when you grab ahold of the exhaust (USE A GLOVE!) and put tension on it?
Does the knocking noise at any time go away?

Answer those for me, we'll help dial ya in a little bit.

Quote:

Originally Posted by Brian Minson

I had some time tonight to get under my cheap Porsche Boxster to look and see what could be wrong. I have a video of me buying the car on my Youtube, in which you can see the white smoke (AOS I am sure) and the loud knocking; I was expecting to see a hole in the bottom of the case. However, I found oil leaking out of the exhaust flange on both sides, I just posted a short video of how bad the oil leaking out is.

I tried running a search online for this issue but didn't see much on it. Lots on the white smoke from the AOS, but not oil dripping out from the exhaust flange. My first thought is the plastic spark plug tubes are shot; a new AOS and new spark plug tubes might fix the oil in the exhaust... but could the fact that the exhaust system is bearly holding on be the loud knocking noise?

Ideas?

Here is the link to the video of the oil dripping out.
https://youtu.be/v8YfelE6Pg0

Thanks,

Brian

thstone · 08-08-2019, 08:39 PM

IF (and that is a big IF) the cause is the AOS, then I would say that you need to stop running the engine. With that much oil flowing through the combustion chambers there is a good risk of hydrolocking the engine (oil is non-compressible) and causing permanent damage.

If it was me, I'd replace the AOS (whether it's the cause or not, its the place to start) and clean the oil out of the air intake and exhaust. With that much oil in the intake and exhaust, it will take forever to burn out so it needs to be manually cleaned out. I also worry that the cat's may have already been damaged from that much oil.

Then start it up and let it run for a bit. You're likely to still get some white smoke but it should diminish. If all goes well, you're done. If not, you're just starting...

Gilles · 08-11-2019, 09:00 AM

Quote:

Originally Posted by thstone

IF (and that is a big IF) the cause is the AOS, then I would say that you need to stop running the engine. With that much oil flowing through the combustion chambers there is a good risk of hydrolocking the engine (oil is non-compressible) and causing permanent damage.
...

Perhaps be a good idea to remove all the spark plugs and crank the engine to remove the excess oil..