Cleaning SAI Ports & Passageways

[logray]

In process of some various engine maintenance on MY 99 996.

Examined the secondary air system yesterday. The lower SAI valve is completely filled with carbon and is not functioning. The upper check valve is still working and it looks like the lower SAI valve has taken most of the carbon build up (hence reason why no CELs). I have a new valve on order and cleaned out all of the plumbing on the top. But now I'm concerned about the passageways through the engine. They are both caked with several millimeters worth of build up.

Has anyone ever performed this cleaning on a 996 similar to 993 procedure?

http://p-car.com/diy/sai/1/sai.htm

Or perhaps have a SAI passageway diagram?

Although I have the cam covers removed already, I'm trying to avoid removing the heads from the block to do this cleaning, since that would mean about $300 for bolts and gaskets.

I know there is an updated combo valve you are supposed to retrofit, but at considerable expense to change out a lot more parts, I opted to stay with what I've got.

TIA!

Edited June 20, 2011 by logray

[dcdrechsel]

Do you think there is any relationship to the oily plugs ?

[Cloudsurfer]

I'm sure they're all gummed up. The ports in the heads are fairly simple, and could be cleaned without too much fuss. You don't need to pull the heads (which is a pretty good size job on these motors), but I imagine it'd be incredibly difficult to do with the motor in the car. With it out of the car, it'd be VERY easy to clean all of this.

[logray]

So i have engine out and cam covers removed. where do the other side of those ports come out, near the exhaust valves?

[Cloudsurfer]

So i have engine out and cam covers removed. where do the other side of those ports come out, near the exhaust valves?

They come out in the exhaust ports, so if you pull the headers off, you'll see the outlets. If you just run some solvent through those passages, it'll clean them up.

[logray]

Thanks. I have some sea foam that I can flush from the top followed by water and compressed air.