Secondary Air Injector Problem

[ahanson]

My 911 has a major issue with its Secondary Air Injector .

My mechanics inform me,...

The car has a check engine light on, We checked the code & found that the secondary air injection system is inop. The ports in the head & cam boxes get clogged & the only way to repair this problem is to dissamble the engine, replace the valve guides & clean the passages in the heads & cam boxes. Until this is done the Check Engine Light will continue to come on & the car will not pass inspection.The total repair runs $5,000 to $6,000 depending on how much work the machine shop has to do.

Does this seem plausible for an emissions issue? Other posts on your site detail this problem but do not suggest this remedy.

Thanks for your help.

The car is a 1997 Porsche 996 Carrera Coupe, with a 6 speed.

[Loren]

I think your car is a 993 (not a 996) and I think the problem you describe is fairly common on 993's. Here is a copy of post from the PCA website where a person fixed this problem without spending a lot of money.

cleaning secondary air injection ports -- SUCCESS!

I just finished cleaning out the air injection ports. It was a lot easier than I expected. I did deviate from your procedure in one respect, which I think made it easier. I replaced the check valve between the air pump and the camshaft housing. Instead of pulling off the solid pipes that supply the camshaft housings, I poured Techron in the hole that the check valve came out of. Doing it this way, I didn't have to mess with the power steering pump or any of the plastic parts on the left side of the engine.

The only issue was that I had to plug all six ports at once. To do this, I cleaned the exhaust port with a carb cleaner and a small wire brush on the end of a drill and then plugged the holes with used chewing gum. It wasn't perfect, but it worked well enough to get the job done. After running the Techron through, I sprayed carb cleaner both from the top and from the bottom using the little red plastic tube that comes with the carb cleaner. It was flexible enough that I was able to stick into each port and spray the carb cleaner up into the passage way. I then blew compressed air through from the top and let everything dry out.

All of the air ports were open, though the #3 exhaust port itself had more carbon build up than the others. Is this common?

The whole job took about 6 hours, which included about an hour of trial and error modifications to a 15/16ths inch wrench with a bench grinder and a torch to fabricate a tool to remove the check valve. One reason it was fairly easy is that I have a lift in my garage. I imagine it would have taken longer with jack stands. Now that I have the tool to remove the check valve and know what I'm doing, I figure I could do this again in about 4 hours.

How often do you suggest to clean the ports as preventative maintenance? Feel free to post this on the PCA website if you wish. I read that some people in Sacramento were going to clean their ports, and I'm wondering how their efforts turned out. Thanks for all your help. It gives me a certain peace of mind knowing that I could see that the ports are completely clear and that the dreaded check engine light isn't going to come on at any time---not because of clogged secondary air injection ports anyway. Take care, Rob.