engine runs roughat idle

[chubs]

got a 2000 Boxster S and runs rough at idle, getting codes for misfire for 4, 5, 6, and I noticed the exhaust collector is oil soaked, ( just that bank)pulled spark plugs and they are wet. checked the AOS by disconnecting it with no luck.also checked for vac leaks, none found.
what would cause oil leak in the whole bank to be misfiring? thank you.

[JFP in PA]

Originally Posted by chubs

got a 2000 Boxster S and runs rough at idle, getting codes for misfire for 4, 5, 6, and I noticed the exhaust collector is oil soaked, ( just that bank)pulled spark plugs and they are wet. checked the AOS by disconnecting it with no luck.also checked for vac leaks, none found.
what would cause oil leak in the whole bank to be misfiring? thank you.

The AOS is failing. Just disconnecting it is not cleaning the residual oil out of the intake and head. You need to run a vacuum check at the oil fill cap, if it is over 5 inches of water, the AOS is toast.

[chubs]

Thanks for the info.
if thats the case how can I get all that oil of the system, also by just going to the oil cap it doesn't seem hard to get out. Another question, why would it fill just one bank?.
thanks again.

[JFP in PA]

Originally Posted by chubs

Thanks for the info.
if thats the case how can I get all that oil of the system, also by just going to the oil cap it doesn't seem hard to get out. Another question, why would it fill just one bank?.
thanks again.

Either let it burn off (takes a long time) or pull the intake apart and clean it by hand.

If you look at how the AOS connects to the intake, the oil would naturally favor one bank over the other.

[bell]

You can pull the plenum and the throttle body as one piece, then reach into the intake with clean tags to get about 90% of the oil out. .... Don't leave any rags in the intake lol

[chubs]

Pulled the throttle body and its full of oil, wii remove the AOS and get one coming.
let you know how it turn out when I install the new AOS.
thanks for the info.