Startup smoke AOS?

[wiebuschk]

I am getting lots of oil smoke at startup but it is intermittent. This was not a problem before I cleaned my throttle body. I am reading that the AOS is a likely culprit and should almost be changed as maintenance so I have ordered one. It looks like Pelican has some special clamps to make the job easier. What else should I look at or order? Can the AOS cause this but not everytime? Vacuum on the oil filler feels very normal.

[blue62]

Originally Posted by wiebuschk

I am getting lots of oil smoke at startup but it is intermittent. This was not a problem before I cleaned my throttle body. I am reading that the AOS is a likely culprit and should almost be changed as maintenance so I have ordered one. It looks like Pelican has some special clamps to make the job easier. What else should I look at or order? Can the AOS cause this but not everytime? Vacuum on the oil filler feels very normal.

To "feel" vacuum at the oil filer is not at all an accurate way to diagnose an AOS issue.
You need a proper gauge to test the vacuum. Do a search here on the forum you should be able to find some threads on the issue. They should show a picture of a gauge and the testing spec.

[JFP in PA]

Besides using digital manometer to properly test the vacuum level, also look at your oil level the sump. We find a lot of cars simply have too much oil in them, which creates this problem, and also significantly shortens AOS life expectancy. On your digital oil level display, your oil level needs to be at least two bars down from the max level; Porsche released a TSB on lower oil levels in these cars several years ago, and even released updated dipsticks for the cars that actually had one, that also moved the full level downward.

[wiebuschk]

My oil level is at the bottom of the top arrow which may be a bit full. I am due for an oil change and can sure fix that. This was not a problem before I cleaned the TB. I've been driving it pretty hard. Thanks for the help guys!

[Gilles]

Originally Posted by wiebuschk

My oil level is at the bottom of the top arrow which may be a bit full. I am due for an oil change and can sure fix that. This was not a problem before I cleaned the TB. I've been driving it pretty hard. Thanks for the help guys!

You can remove the oil filter canister and empty it to remove a bit of oil and check it again..

[wiebuschk]

I also have a bit of an surging idle issue. This really seems like vacuum leak.I likely disturbed something while cleaning the TB. If I spray starter fluid in the vicinity of the Y connector and vacuum tank I get a slight rpm surge. This is foreign land to me. What breaks or splits in that area?

[blue62]

Originally Posted by wiebuschk

I also have a bit of an surging idle issue. This really seems like vacuum leak.I likely disturbed something while cleaning the TB. If I spray starter fluid in the vicinity of the Y connector and vacuum tank I get a slight rpm surge. This is foreign land to me. What breaks or splits in that area?

could be the Y connector
Could be one of the hoses
Could be the vacuum canister.
If there is a one way check valve it could be the check valve.

With your surging idle.
Run your RPM up to 2500-3000 RPM and hold it there for say 20-30 seconds.
If the engine smooths out and runs normal then it is very possible that it is a vacuum leak.
If it will not smooth out and run normal or very near normal then it is something other then a vacuum leak.

Do the above test with a fully warmed up engine.

[wiebuschk]

Installed the AOS. I think the ribbed hose on bottom was split. I poked me finger right through it. The Y was solid and the check valve was working. I also replaced the ICV with a $20 ebay one. I worked like a champ. She is purring with no smoke. Leaving her on stands and will change oil tomorrow.

[blue62]

Originally Posted by wiebuschk

Installed the AOS. I think the ribbed hose on bottom was split. I poked me finger right through it. The Y was solid and the check valve was working. I also replaced the ICV with a $20 ebay one. I worked like a champ. She is purring with no smoke. Leaving her on stands and will change oil tomorrow.

If you have something like a Handy Vac you can attach it to the vacuum canister and pull a vacuum on the canister and see how long it holds the vacuum.

[BrakeExpert]

I'm not sure if this has been said, but this is a flat 6 porsche engine, a little oil puff on startup has been commonplace among porsche since forever.

the AOS clamps are normal self-tensioning spring clamps, they arent too hard to do if your good with locking pliers. the clamps they may have mentioned have basically plastic clips on them holding them 'open' so when you put them on by sliding, theres no wrestling, you undo the plastic part and the spring clamp springs onto its normal tension. I for one prefer the auto-tension clamps that have those extended arms on them you can grasp wih your fingers so you dont need pliers.