Did I toast the engine?
 

Help!

I was driving home one evening and noted that my 2002 Boxster S with Tiptronic was a running a bit rough. Not thinking much about it, I finished my journey and exited the interstate where CEL and low oil pressure light suddenly illuminated. Knowing I had but 2 miles to go, I decided to press on home. As I pulled away from the stoplight the car turned into a mosquito sprayer. The poor folks behind me were treated to one heck of a smoke screen. Crap! AOS failure! I limped the car home and parked it.

Thanks to the folks at Pelican I was able to order a new AOS and proceeded to replace the unit. At the same time I changed out the spark plugs and noted that all were oil fouled. With new plugs in place, and a fresh oil change I started the beast back up.

I now have a consistent ticking noise from the engine that has the sound of lifter ticking. Further, the oil pressure light is solidly illuminated and I was throwing a P1325 code

The car appears to run ok and does not appear to be lacking for power (just drove it for a quick run around the block). Could the AOS failure have resulted in damaged lifters, or vario cam issues? I don't want to pull the motor or access the cams if I can avoid it.

Any help or advice would be appreciated

Doesn't sound good. You likely damaged the motor by running it with low oil pressure. Since the oil pressure light is still on DO NOT EVEN START THE CAR. Oil pressure light means turn the motor off right now!

Drop your oil filter and have a look at it; if it is full of metal, the engine needs to come out.

During the initial oil and filter change after the AOS failure I didn't note any metal fragments...But it's worth another look see...

Regarding the oil pressure light, check the actual pressure with a mechanical pressure gauge just to be 100% sure......
Is the "ticking" sound @ engine speed (bearings / pistons) or half engine speed (valves / lifters)?

I just bought my 986s in Florida and drove it home 1000 miles with a oil light on. I listen and feel my engine over relying on the oil pressure light. That's bc if it truly is a oil pressure problem then you're just going to need a new engine. If there is a real reason you have low oil pressure 9/10 times its only fixable by a rebuild.
My issue was that the asshat used the wrong weight oil. Did a oil change to 0w40 and the light was gone.
Ticking is a usual noise for low oil pressure do to something mechanical. Either internal bearings are gone or your oil pick up is clogged with debris.
Your plugs were probably oil soaked from the AOS going out. It'll just dump oil into the intake manifold when it's blown.
I'm just speaking from experience.

Thats not a lifter... You more than likely injured a cylinder, or a piston.

That noise that sounds like a lifter fools people all the time, and they waste money. Its easy for an AOS failure to impact a cylinder, or a piston. The sound is EXACTLY like a lifter. The noise may also be a rod bearing thats been injured from having low oil pressure.

Driving with a bad AOS is murder in way too many instances.

The reason the OP light was on is because the extreme vacuum created in the crankcase by the AOS failure was pulling oil away from the oil pick up tube. Again, this is normal for AOS mode of failure #2, it just means that the membrane failed in the opposite manner that it does most of the time, and this is the most harmful.

With the OP light on you had less than 6 PSI of oil pressure. Thats not enough for more than 2,500 RPM of safe operation without damaging internals.

Don't judge a book by it's cover. Pull the oil sump and look for material, then pull the filter and cut it apart. If the issue is a cylinder it will often NEVER have debris in the oil.

Low oil pressure and AOS failure at the same time seems strange to me… Would loss of oil pressure cause a premature failure of the AOS?

note: posted my question before I saw Jake's post... Thanks Jake.

Not strange at all.. Just a different mode of AOS failure. The AOS fails and direct manifold vacuum sees the crankcase in excess of 24" of water. This creates turbulence in that impacts the pool of oil in the sump, and pulls it away from the pick up tube, as well as creating extreme aeration of the oil.

Aerated oil has no ability to create pressure, and has no film strength.

Completely normal, and expected. This is by far the most harmful of the 4 ways that an AOS can fail.

The loss of oil pressure does not cause the AOS to fail, in fact the primary and secondary issues are inverted from that.

All the AOS failures I have seen resulted in white smoke. Is it common for the issue to sometimes result in black smoke?

The basic rule for the oil pressure light is that if it comes on, you MUST turn off the ignition immediately. Continuing to run the engine with no oil pressure means certain damage to the engine. I have a bunch of cases where people damage the oil pan, lose the oil and continue to drive with the oil light glowing. It invariability ends in engine replacement. Had they turned it off as soon as the light came on, it may have lived. I hope for your sake that you just have a lifter that isn't pumping up, but I'm not optimistic.

My guess is that the noise you are hearing now is a bit of rod knock. I think that it is time to pull the pan to assess the damage.

If you do keep driving it, and it is a rod bearing, chances are very good that it will fail catastrophically. I saw a Boxster that had been driven with rod knock, ending with a beautiful R&R rod breaking and destroying what had been a very expensive engine. The sad part is the owner heard the noise and decided to press on. That was a very expensive decision.

Yes, it can IF the manifold vacuum and planets align well enough to add fuel trim, resulting in excess enrichment, which leads to black smoke.

People think that every AOS fails the same way, thats not the case- symptoms and exact failure varies. I have seen AOS' fail and the engine never smoke at all, just make a vacuum squeak past the front main seal, and turn on the OP light, then fail like the original poster's has.

Because people don't know all the modes of AOS failure we see cars that are thought to have completely failed, and all they needed was an AOS. I have received these cars after plucking them off dealer lots 3,000 miles away, and fixed the issue in less than 1.5hrs.

That guy was told that he needed a 22K engine, I fixed it for 400 bucks.