Premature AOS failure?
 

Hi guys!

Two or three month ago I diagnosed a bad AOS on my car, not serious, but enough to trigger the check engine light.

I replace it with a "URO" AOS, it worked fine... until today.

I have to check fuel pressure and vacuum lines, but there's 99% chance that it's the AOS again, the CEL came on in the same conditions.

Otherwise, the car runs perfect, idle is good, it's got power, revs happily.

Long term fuel trim is at +1.6%
Code P1128 and P1130

My question is, do you think my cheapassery is the cause here? Or something else can cause the AOS to fail prematurely (I can't figure what would)?

Thanks!

Ben

When I got those two exact codes it was because the hose from TB to AOS was not seated correctly on the TB side. Car always ran perfect with that condition. Once I reset the hose, no more codes.
They are codes that tend to point to a Vacuum leak.
Are you seeing any other symptoms, Smoke, High vacuum(oil filer cap hard to remove)? Can you hear any sore of vacuum leak

Could very well be the case. The OEM AOS units have an inordinate level of failures, some literally right out of the box, so I would not be at all surprised to see an aftermarket unit crap out quickly.

Sadly , URO have a poor reputation on the MB & BMW Forums. But since the Porsche branded AOS units are also unreliable -don't beat yourself up for trying URO.
As a diy proposition, buying from the dealer's Parts Dept. and trying to claim a defect a few months later is a dismal situation. Since it is also a horrid job , seems a better idea to give the task to your local Indie.He has way more leverage with a Parts Supplier than a mere diy person.
OTOH , invest in a Smoke Machine and locate a leak quickly? I bought one of the best 'paint can +baby oil' systems.Yes ,it sounds laughable but it works very well. I hate hunting vacuum leaks and these cars are the worst because of access and heat damaged/brittle plastics.

I'll check everything else tomorrow in the shop at school
The PCV hose is "new" but could very well be the problem.

Yes that's what I thought...
Before I replace it, the "old one" was a 18month old!But I don't think it was OEM either.

Thanks guys!

If I find it defective, it should still be under the 24 months warranty, so I'll just replace it.

The install isn't that bad if you have this:
https://www.pelicanparts.com/catalog...63000-M219.jpg
It makes the job a 35min job ;)

I find the URO units missing parts all the time! Sometimes its the spring, other times its a diaphragm. I only use Mann, and even then they still fail early.

The blue clip shown on the spring band clamp is made by Mubea:
Mubea - Products & Technologies - Industry - Products - Spring Band Clamps - Pre-opened Spring Band Clamp with Handy-Clip
But a Mayhew 28650 remote pliers set would be better - if you are a tool hound?
Pelican Parts.com - Spring Loaded Cable Hose Clamp Pliers

I got the AOS replaced...
now instead of throwing a code once every week, it does every day...

I'll check if everything is correctly installed but I guess I have another defective AOS... cool!

Next time I'll get an OEM, see if it makes things better.

Ben

Ben,
Please let us know if you find a brand of AOS that works?
Since the AOS can not be dismantled easily ,we'll never know what the specific defect is in the URO brand AOS.
I have found Pelican to be very honorable about returns.
My suggestion is to ask Pedro who he buys from -he is near you?
PedrosGarage / Technolab South Florida firm dedicated to the Porsche Marque
Jake has a new product in development to solve this issue.
See the other current Thread on AOS -'More stupid AOS talk'.
" AOS units simply are not lasting these days. The latest run from Mann has proven to have issues, as I have experienced them several times in the last couple of months.

We've been testing a product for a while thats almost far enough along to pitch to distributors. If they accept it, the AOS problems will be over."
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