AOS replace

[abporsche1]

Time estimates to replace? Opinions on engine in or out? Any other repair/replace "while your in there"?
Barry

[Dmitry at Pelican Parts]

Hi Barry - take a look at the link below to a link from our site's DIY tech articles on the procedure. Please let us know if you have any questions.

Porsche 911 Air Oil Separator Replacement - 996 (1998-2005) - 997 (2005-2012) - Pelican Parts Technical Article

[abporsche1]

Thanks Dmitry, I did scan over but not read all the article. I'm busy pouring time and $ into a remodel. Knowing the hrs it takes to do the AOS tells me what to budget for that too. I could do it myself, but time won't allow.
Barry

[JFP in PA]

Originally Posted by abporsche1

Thanks Dmitry, I did scan over but not read all the article. I'm busy pouring time and $ into a remodel. Knowing the hrs it takes to do the AOS tells me what to budget for that too. I could do it myself, but time won't allow.
Barry

A decent shop should charge you about 1-1.5 hours

[JFP in PA]

Originally Posted by abporsche1

Thanks Dmitry, I did scan over but not read all the article. I'm busy pouring time and $ into a remodel. Knowing the hrs it takes to do the AOS tells me what to budget for that too. I could do it myself, but time won't allow.
Barry

A decent shop should charge you about 1-1.5 hours for a Boxster; 3-4 hours on a 911 variant.

[abporsche1]

Thanks JFP. You inadvertently pointed out I should have a signature. Let's see.....

[TNT79Bronco]

I will give you a slightly different perspective on going about replacing the AOS on an engine. I have done it twice, on two of the 996's I have owned. Granted, both of the times were on project cars, that needed to have an engine swap done anyway, but I was sooooo glad that the engine was out to replace the AOS and even associated hoses. While the engine was out, not only did I address the AOS, but I also was able to easily replace the water pump, thermostat, spark plugs, starter, misc sensors, alternator, belt, RMS, and the coolant reservoir. Had either of them been a 6 speed, I would have done the clutch at the same time. I was also able to check for any leaks and address them at the same time. It was also a good time to clean the engine, which will help with any future leak identification.

If you aren't worried about all those other items I mentioned, or if the car has low enough miles that it isn't an issue, then just address the AOS.

I guess what I am saying, is that if the AOS is bad, the car might have enough miles on it to just drop the engine, and make sure you can address as much of the stuff at once, without having to pay for duplicate labor and have peace of mind knowing that it is ready to rock for another 50,000 to 100,000 with those items changed.

I also realize that I saved a ton on labor costs doing it myself, and that allows me the flexibility to buy my own parts and take my time. A luxury not everyone has.

[yelcab1]

I don't think I can do this in 4 hours with the engine in a car for a 996 and I have dropped 20 911 engines in all years. This is not my first rodeo. The access to the AOS at the left hand front side is way too severe. With the gearbox out of the car, maybe. With the engine out, it is a much more manageable job.

[ltusler]

IMHO the Bronco has it right.

[abporsche1]

Bronco answers my 2nd & 3rd question, thanks. The time it takes will be relative amongst the many good Porsche shops around here.

My initial question was because of milkshake sludge in the oil filler - thinking a failing AOS can cause it. So there's another question, what causes the sludge?

Last weekend I did the vacuum test side by side with a 2003 C4S with a known good AOS, both were sucking similar and were relatively easy to remove.

[tonythetarga]

Originally Posted by abporsche1

Bronco answers my 2nd & 3rd question, thanks. The time it takes will be relative amongst the many good Porsche shops around here.

My initial question was because of milkshake sludge in the oil filler - thinking a failing AOS can cause it. So there's another question, what causes the sludge?

Last weekend I did the vacuum test side by side with a 2003 C4S with a known good AOS, both were sucking similar and were relatively easy to remove.

Oil sludge is possibly engine oil and coolant intermix. I’d investigate that before buying an AOS.

[Wheel Dynamics]

If you have a Tip and not stick then it's a whole other animal to gain complete access to the OS, last week were pulled the motor in order to gain full access which also allowed us to find and fix a couple of broken vacuum lines that aided in clearing a check engine light.

To drop the motor and change it is around $800 in labor plus around $150/parts

[yelcab1]

Originally Posted by Wheel Dynamics

If you have a Tip and not stick then it's a whole other animal to gain complete access to the OS, last week were pulled the motor in order to gain full access which also allowed us to find and fix a couple of broken vacuum lines that aided in clearing a check engine light.

To drop the motor and change it is around $800 in labor plus around $150/parts

You can see that whole side covers in sludge. Yuk

[Wheel Dynamics]

Originally Posted by yelcab1

You can see that whole side covers in sludge. Yuk