Replacement Air Oil Seperator (AOS)

[gwyn.roberts]

Hi. Looks like my Boxster needs a replacement AOS due to white oil smoke on initial start up. Only happens once on initial starting, then no smoke. Looking for advice on garages in North Wales who could do the job? Thanks

 

[marc_tt]

Does the smoke happen every time you start the car and if so how frequently are you using the car and is it parked level?

If it's been standing for some time or parked sloping, it's common to get initial smoke on start up that then stops and probably not be AOS fault. Had this with Boxsters, including after changing the AOS, and both indie and OPC confirmed it's just one of those things.

Suggest check the airways to the throttle body for signs of oil build up - loosen the jubilee clips, remove and clean the airways and reinstall. Then use the car for a while and check again.

Your local garage should be able to replace the AOS for you - access is fiddly and otherwise relatively simple to change.

I've done it myself and was fortunate that our local garage let me use one of their lifts.

 

[gwyn.roberts]

Does the smoke happen every time you start the car and if so how frequently are you using the car and is it parked level?

If it's been standing for some time or parked sloping, it's common to get initial smoke on start up that then stops and probably not be AOS fault. Had this with Boxsters, including after changing the AOS, and both indie and OPC confirmed it's just one of those things.

Suggest check the airways to the throttle body for signs of oil build up - loosen the jubilee clips, remove and clean the airways and reinstall. Then use the car for a while and check again.

Your local garage should be able to replace the AOS for you - access is fiddly and otherwise relatively simple to change.

I've done it myself and was fortunate that our local garage let me use one of their lifts.

Thanks for your reply Marc. The car is a 987.2 2010 Boxster S with 37,000 miles. It’s used 2/3 a week and kept outside on a level drive. I’m thinking it could be an AOS problem after speaking to other Boxster owners. I’ll take your advice onboard when consulting a garage. Thanks

 

[Motorhead]

Something else to throw into the mix Gwyn. Unlike in-line and V-configurations the boxer layout means that oil can collect more readily in the bores when the engine isn’t running, with some no doubt remaining in the volumes above the pistons, and this will be burnt-off on start-up leading to some smoking.

Also if the car has been standing outside over the now cooler nights, condensation will collect in the exhaust system and water vapour will appear on engine start.

One 987.2 Boxster owner on here [911hillclimber] who had the same issue for an extended period - even when the AOS was replaced - appears to have found a solution by keeping the oil level one bar below the maximum.

Jeff