Second AOS in les then 2500miles. What could cause that?
 

Hello All

2000 Boxster S. In november I had problem with smoke on startup and sometime on had acceleration with rpm over 5000. I change the AOS and the MAF from Pelican parts. All was working good.

Now wednesday night, lots of smoke while coming home. Now lots of smoke on start up, and very hard to old idle. code P0102 related to MAF, but with all the smoke I think its the AOS again causing the code. So I just open the intake and its full of oïl as expected. So I guest the AOS is blown again.

What could cause the AOS to broke in less then 2500miles?

Later all
Chris

Its worth checking the bank 1 scavenger pump is okay (its just below the AOS). If the pump is not working or the wrong way around, it will not pump the oil back into the sump effectively. This in turn means the oil going into the AOS cannot drain back into the crankcase, this results in the aos overflowing and blowing the other way into the throttle body.

I blew 2 AOS in a month as a result of my pump failing (ironically the other pump was fitted wrongly too!). Just finished rebuilding my engine and re-timed it today.
Get the car in the air intially and check the pump is the right way around for a start.
Good luck

Too much oil in the crankcase... Were you over the top mark on the oil level?

As I recall, there are two PCV's and if they are not funtioning they can cause an increase in pressue that can cause the oil separator diaphragm to fail. Just found a source for this - it was under the comments and suggestions after the Pelican Tech Article on replacing the Air oil separator.

Oil level was perfect, just a little Under full on the dip stick and always withing the marge on the electronic reading in dash. So oïl level was ok I think.

PCV? I dont know about that, I will do a little reading. Anyone can shime in?

Thanks
Chris

Srad34

I just Look at the pump and it is install in the right direction. Passenger side pump has 1-3 facing inward. I did not look at driver side. There is a lots of grunt accumulated near the pump. Oil mix with dirt. Look like it's coming from the sensor close to the pump on the side. Cam sensor I think. I wonder if it could be related.

Can I simply unbolt the pump and take it out to see if it turning freely? Will I make a big oil mess?

Later
Chris

The exact sensor name where there seam to be oil leaking a bit is the camshaft timing advance selenoid.

Later
Chris