Air/Oil Seperator write up?

[mikes_box]

Originally Posted by kevinniven

Just called the shop, they want $300 to replace.
Is this truly something the avg person can do at home?
thx guys

$300 for parts and labor is not bad at all. It can be done at home for a few hours of work and cursing for about $100 in parts.. If you do it at home make sure you buy the hose clamp pliers and a new hose clamp that you can jus screw ith your fingers...

[Kevfra]

Quote: Most of the failures I do see involve cars with 60-70k miles on them, and it appears to be heat related (air temp 100+ and ground temp 115+) which would equal REALLY high engine compartment temps. This is the ONLY "common" denominator so far. End Quote.

Well mine failed at 60,000 miles on a 102 degree day in slow traffic, so compartment temps were extremely high, plus AC running full tilt. One wonders... why put a heat sensitive part up against an engine?

Two points to mention - I found that using a small vise grips on the bellows clamp during removal was the way to go, as simply using pliers wouldn't do the job.

And second, regarding removing the compartment cover, the ball/socket cable on mine has a small C clip that has to be removed before popping out the ball. Swing the C to the side, then raise it until it comes clear, then pop the ball out.

Fabulous write-up and extremely helpful - many thanks Brad!

[Tool Pants]

The temperature related theory is interesting. However Peter Smith thinks it is due to cold air that causes the rubber diagraphram to split.

Unlike the Boxster, the separator on a 996 is heated by coolant. This is a 996 separator and you can see the 2 provisions for the coolant hose into and out of the round thing which is the diagraphram.

[Kevfra]

Well I replaced mine - and still have white smoke, although perhaps not as much. I have to drive it to see if it clears, and if the sucking comes back to the oil cap.

Isn't this thing just a minor smog control device, to capture vapor from the crankcase and burn it? In the old days (and on other cars) that would be a very simple matter. This thing seems overly complicated and prone to failure.

[Kevfra]

OK - no smoke. Here is what I think...

While I was under there scratching my head, I decided to change the oil. It took about twenty minutes to drain, and I don't mean a slow drip. It was a steady stream of about 1/8 inch diameter for twenty minutes, obviously way longer than it should take if all the oil was in the pan.

I think the AOS failure sucked oil into another area of the engine, and it was sitting there which is why I still had smoke after I replaced the part. But by completely draining the oil I removed it from the inappropriate area - and life is good.

Just put twenty or so miles on it and things appear normal and happy.

Still think it is a stupid design...

[Sain0rs]

First off, amazing job with the DIY. I had been concerned about the smoke issue late last year for my '03 S and bought the AOS from pelican parts but hadn't gotten around to installing it. Yesterday the smoking on startup and while running has become extreme so I intend on installing the new AOS.

However, Pelican has two AOS units for sale. The one that I bought (Oil Separator, Boxster/Boxster S (2003-04):
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=996-107-026-01-M100&catalog_description=Oil%20Separator%2C%20Boxster%2 FBoxster%20S%20%282003-04%29%2C%20Each

And the one that resembles the AOS in your instructions (Boxster/Boxster S (1997-02) up to Eng # 65X01419):
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=996-107-023-04-M100&catalog_description=Oil%20Separator%2C%20Boxster%2 FBoxster%20S%20%281997-02%29%20up%20to%20Eng%20%23%2065X01419%2C%20Each

Anyone have an idea if the install is much more difficult for the 03-04 AOS?

[gschotland]

Sounds like you don't really have a choice either way unless the alternative is paying someone else a few hundred bucks to do it. Go for it! And share your results with us on what differed from the write up.

[chrismanchr]

Originally Posted by Tool Pants

The temperature related theory is interesting. However Peter Smith thinks it is due to cold air that causes the rubber diagraphram to split.

Unlike the Boxster, the separator on a 996 is heated by coolant. This is a 996 separator and you can see the 2 provisions for the coolant hose into and out of the round thing which is the diagraphram.

I can maybe confirm this thoery about cold air ,as my AOS (2.7 987) failed on the coldest day of our winter so far ,it was -17c ,and the engine been running very rough since ,plus an oil drip down the back of the AOS ,the engine sounds like its either got an exhaust leak or induction leak or both ,plus slight oil smoke like one of those misting machines you use to get at 1980's discos

when calling a porsche center for the part they have had lots of orders for the same part ,the 987 AOS is a bit different from the 986 version and doesnt have the boot or the plastic tubes on the bottom but a hose (with one of those clips that are sometimes impossible to remove) and a spigot with an O ring ,also mounted / bolted differently

[986_Ron]

Just wanted to post a quick thanks to Brad Roberts for the write up. My AOS failed on my 2000 986 with 99,067 miles on it. Spent a couple hours this afternoon swapping a new one in. Everything went smooth and it saved me a couple of hundred bucks.