AOS Related?
 

Symptoms:

• Codes P0507, P1128, P1130
• Light misting of oil around AOS area
• Slightly erratic idle

Things I've done so far:

• Cleaned throttle body
• Cleaned MAF
• Replaced and resealed oil filler tube
• Cleared codes

I'm still getting all the same codes but the car drives much better now. Not seeing any more oil mist in the engine compartment either. So, my question is this...

Is it possible this is the AOS even though I don't have any smoke ever coming from the tailpipe? I also can find no oil residue in any pipes where it shouldn't be.

Anything else I can check for? A vacuum leak? Is there a systematic procedure? I've searched the forums and read all I can... Need some direct help. Thanks!

I had the lower pan seal done at Porsche Orlando 3 months ago. It appears that it needs to be redone. Can this possibly be the source of my vacuum leak?

2000 Boxster S
80,000 miles
Well maintained. No major issues.

If I had to guess, I'd say there are a couple things going on here.

0507 is Idle Air Control above limit

the possible causes are:

Throttle valve is sticking

Leaks in intake air system

So, I'd recheck the intake for leaks and also that the throttle isn't sticking (you may not have cleaned it thoroughly enough)

1128 and 1130 have possible causes of:

Leaking intake air

Incorrect MAF signal

Here, again, leaks should be isolated and you may not have cleaned the MAF thoroughly, or cleaning it may not have worked (about a 50% sucess rate on cleaning) and may need replacing.

Durametric Readings
 

I just received my Durametric dongle. I can see that I can get a signal reading from the MAF with the software. Is there a way to test the MAF or is there a signal reading that tells me if it is going bad?

I will try re-cleaning and resealing everything tomorrow.

Thanks Lil' Bastard

Disconnect your MAF and drive the car. The DME will revert to default air/fuel mixtures. If it runs and drives better, replace the MAF.

Here's a graph of a MAF/rpm test I did -- although I have a later model, you should be able to use the chart as a guide. Good luck.

Regards,
paul...

Ok... tested the MAF today with Durametric.

Voltage with Key in is 0.9v-1.0v with 0 Air Flow
Voltage with Engine at Idle is 1.4v

I would have to think that the MAF is OK with those readings. At least that is what I've read.

The car has started to run rough at first ignition for the day. Throaty sounding pops from the driver side intake. Engine sounds like it might stall then it catches itself. After it drives for a little bit it is fine for the rest of the day. I took the padding and rear shelf off the engine compartment so I could hear the engine better while driving.

2 things I have noticed.

• There is a wind like sound coming from the engine. I can not locate it though. tried the carb cleaner trick with no success.

• There is also a whooshing sound if you tap on the accelerator just before the engine revs.

Any ideas?

Sorry if this has been covered before. I search this forum (and others) actively, but most of the threads I have read just end without a definitive solution being found.

Lots of good recommendations though.

Sorry for resurrecting an old thread, but thought it best to post what finally fixed my 986.

"It was a vacuum leak.

- Accordion tube from AOS.

- Rubber Sleeves on intake manifold.
(1 was bad, but replaced them all.)

- Throttle Body housing was a little bent (heat?)

- Oil Filler Tube was good, but replaced it anyway.

I will update my post later... sorry for not doing so already.

BTW - MAF was/is good and AOS was/is good. I wound up not replacing those parts.