Secondary Air System (the likely culprit?)
 

Hello all,

I have a 1997 Boxster. The check engine like comes and goes and it's the result of the Secondary Air System (SAS) goofing up. My mechanic said it will cost about $800.00 to replace all the parts in the system. His suggestion is to do this all, because you can't really figure out exactly what part is the culprit, and you're better off just replacing everything once.

Ok fine....here's a little story.

The check engine light was off, and had been off for several weeks. About two weeks ago on a cold morning, I backed out of the garage, forgot to put the trash out and then shut down the engine DURING the 90-120 second SAS drill where it does it's thing (the time period when you can hear the SAS pump). About 10 minutes later after the trash was out, I fired up the car and BOOM! The damn Check Engine light went back on. CRAP!! 15 days later (about 7 actual driving days), the light went off again.

So...I'm thinking I caused the problem by shutting down during the SAS sequence of events and perhaps interrupted the primary valve (Kombi valve???). As a result the valve was either stuck open or closed (I'm guessing open).

If my thinking is correct, and the valve is the problem, is there a way I can access this valve and somehow persuade it to close/open appropriately? This could at least confirm what part I should replace.

Little back ground...1997 Boxster with 37,000 miles. As you can imagine the first two owners kept it shiny in they're garage, but I drive it about every other day on average. It has been very well maintained over the years and just about everything on it is in perfect working condition (except the darn SAS).

Thoughts?

Adam

I had the same issue with my low mileage '98; turned out to be a cracked plastic Y hose connector. My local Indy had see the same issue before...

Is that part easy to get to? Is there a way to trouble shoot that?

Thanks!

To test functionality of shut open/off valve you need to pull off little hose at Combi valve put a hand vacuum tester to it then pull off SAI pump hose at motor and see if you can blow thru the valve. Release vacuum and then see if it's now obstructed when blowing in. The valve is just like a switch open/close.

By shutting off engine it would have automatically ended the SAI test. It only happens on cold starts. What was the code? Don't know on early models but on my 02 you either have to pull off the induction T or pull out alternator. Both a PIA.

There are diagnostic tests that can be run to test each component in the SAS. It only takes a couple of hours to run the tests. Its not brain surgery and if he is really a Porsche mechanic, he should already know how to do these tests.

If your mechanic is unwilling or unable to do this, maybe its time to find a new mechanic.

Sorry, but this kind of stuff really peeves me. The whole point of paying someone $120+ per hour is because they are supposed to be knowledgeable and expert at repairing Porsche cars.

What were the codes associated with the CEL? If they were P0410 and/or P0411, there's either a SAI valve problem or a leak. Once confirmed, it might be a good idea to change our the parts given the possibility they might be brittle and prone to more cracks/leaks in the future. Be sure to test the vacuum reservoir