I had the secondary air injection (SAI) valve replaced as a prophylactic measure, before in clogged up and failed on me...not bad science here. The one that came out after 65,000 miles was ugly, very ugly and rusted up.

About 6 weeks later, I noticed that upon start up, there was a gurgling noise in the engine compartment that had not been there before; it sounded ugly and expensive (It was!). The noise went away when the SAI air pump turned itself off after the first few minutes....I knew something was very wrong, and some big problem may have been lurking on the horizon.

When I have a strictly Porsche factory parts related issue, I take my car to Porsche dealership in SoCal. Reason #1, a very trusted technician works there and he has never has let me down. Nothing seems to stump him...I have had him do various litle things on my car for the past five (5) years.

First thing he does is pull off the airbox, and dive into the SAI...he pulls it out, and the supposedly one way valve, is now two (2) way...somehow the SAI had failed and it was replaced again. The air box goes back on...start the car...the bloody noise is still there...off comes the air box again.

What my tech discovered is that a freeze plug in the side of the Air Distribution housing had blown out...it had been blown out for a while based on carbon deposits...next, he finds that one (1) of the air distribution tubes, that directs cold air to the exhaust passages upon start up had pulled out of the nut housing that secures it to the motor.

Of course there are none of these little tubes in the US, and nary a one in Germany, so he scrounged up a tube off a engine destined for the scrap heap...hole in the block or some such malady.

New air distribution tube, new SAI, new Air Distribution Housing and I am back in business.

Note the "freeze plug" with a nice hole in it.


You can see where the tube has pulled out.

If you hear a gurgling upon start up, no worries, its just dollars trying to get out of your wallet and work their way into someone else's pocket...keep the economy moving I say!

 

Martin, find a freeze plug in this size and press it in. Then you'll have a Rennlist spare

This one looks as though it has rusted from accumulation of exhaust system condensation.

 

It is a beautiful little casting....they only cost about $200...a freeze plug would be abou $0.10...makes sense to me!

The air line is close to $100...wow!

 

With my luck, I'll blow that little $.10 freeze plug out with the 125psi of air I'm trying to cram through my SAI passges right now. At least now I know how much it'll cost to fix!

Jason

 

Was the end that pulled out, not just a flared end that could have been re-flared? Closer pic of that end?

 

Read the red script that follows. CLEARLY it applies to the 993!

 

The end was not flared...the intact end is flared. Without talking to the technician, it looks that the flared end was brloen off, and as a result, was too short to be re-flared and re-installed. But that is a good point; I'll ask him. Why even I know how to re-flare a piece of tubing!

 

Very interesting Martin. My past 993 had this gurgling sound, and it ALWAYS worried me. Maybe I should be glad I sold it when I did.

What do you think are the net effects of this failure if unaddressed? Could it cause SAI clogging? Prevent it? Cause a CEL?

 

Eric writes, "Could it cause SAI clogging? Prevent it? Cause a CEL?"

I can't really say...but for certain, the hole in the side of the Air Distributor Housing (We think the cause of the gurgling sound) would make the SAI system nearly inoperative. The air from the air pump would take the path of least resistance I would think and go right out the hole with very little being routed through the air tubes to the right and left banks of exhaust ports.

Somehow, some way, the failure of the air distributor housing was appears to have been connected with the failure of the SAI valve itself. The SAI had just been replaced in December of 05.

When it came out this time, the formerly one (1) way valve was now a two (2) way, completely open passage way...with the valve mechanism destroyed. I only lived with the gurgling sound problem for about 2 to 3 startups before I had it fixed. The SAI system was down for a very short time, hopefully too short to have caused any damage. Time will tell....If I cet a CEL; I'll just get it fixed..let's hope I don't see one of these things!