dsmyth

This may be a one off situations but a close inspection while cleaning the part after a new valve was being installed uncovered a gaping hole. One of the two anodized plugs on one side had what I thought was a small spec of dirt on it. I went to pick it with my figernail and it went through what looked like a perfect gold coloured plug like it was wet tissue paper. The car only has 30k on it and may be a result of moisture sitting for long periods of time, defective coating on one side of the plug or just bad luck. The other plug is perfect. Just a heads up when changing the SAI valve. Doug

User 122821

Someone else here on rennlist had the same issue. It seems to be either corrosion or too much pressure. maybe both.

dsmyth

I was not aware this was previously caught. My SAI passageways are like new still( I know as I have cleaned out a few for friends) so I am not sure where the pressure would come from. The strange thing was the coating looked so perfect on it escept for this little black spot in the center. It was like putting your finger through wet tissue paper. A strange experience. I wonder if the caps are available to repair it? Doug

bruce7

If there is a hole in the plug then unintended air could be drawn into
the exhaust stream. This could trick the O2 sensor into thinking combustion
is lean. One might expect to see positive fuel trim numbers > 10%.

dsmyth

It was solid before I touched it with my finger. I presume at some point in the near future it would have dissolved and let air in. A good find as it would have taken a while to diagnose.

JB 911

Good find. I imagine a corroded /missing plug would have a similar effect on the system as a non functioning check valve.

Was the base removed with engine in?

willus

FWIW, mine looked the same when I took it out recently. I planned to post a photo but hadn't gotten to it yet.

If anyone has a solution for repairing it, I would love to know it. My local shop said to just replace the whole assembly, but that seems overkill for a couple of caps.

To my inexperienced eye, the caps look to be yellow-zinc plated and that plating is getting defeated.

TJ993

Hey Doug

Glad to hear you have your new Valve Installed.
Sorry to hear about the manifold ? issue

There was a Prior Post by: C4S_fan
"SAI Flush Update...look at what we broke"
Pics are attached
FYI
Regards
Tom



[QUOTE=dsmyth;12187427]This may be a one off situations but a close inspection while cleaning the part after a new valve was being installed uncovered a gaping hole.

nine9six

Doug,
If need be, here is a potential cost effective replacement...

[url]http://www.ebay.com/itm/Porsche-911-993-SAI-Secondary-Air-Injection-Manifold-Air-Tube-Carrera-C2-C4-/111483153427?pt=Motors_Car_Truck_Parts_Accessories&hash=item19f4e9ec13&

Hope this helps...

Im puzzled as to the cause...If it was moisture, would not gravity corrode from the bottom edge, and be thinner at the bottom? As you also thought; maybe one of the plugs missed an anodize processing on one side?

Maybe a previous SAI clean with a caustic chemical that attacked the plug? One guess is as good as the next

Paul M

https://rennlist.com/forums/993-foru...fold-help.html

vincer77

Wow. After reading so many SAI threads over the years I have never read about this failure. I would expect that ifyou only replaced the SAI valve and you had a leaking plug you would still get an SAI code.

MDamen

I had the exact same failure. I cut a small piece of sheet metal to fit the hole and then glued it in with JB Weld epoxy.