Cleaning SAI Ports...DIY Write Up
10-11-2004, 12:22 AM
#1
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Thread Starter
Cleaning SAI Ports...DIY Write Up
I just finished cleaning the secondary air injection ports. Several people have asked me write it up as a DIY, so here it is. Don't be afraid to tackle this job. If you can change your own spark plugs, you can do this.
CLEANING SECONDARY AIR INJECTION PORTS
AND CHANGING SAI CHECK VALVE
This DIY provides a relatively easy way to clean the secondary air injection (SAI) ports and replace the SAI check valve. The car is a 96 993 with 40,000 miles. The car is stock except for a K&N cone air filter. The parts cost about $200. The job took about 6 hours, but this was done with the car on a lift. (Photo 1) I suspect doing this with the car on jack stands would take longer.
http://forums.rennlist.com/upload/im001671.jpg (1)
The basic procedure is to put solvent and compressed air into the SAI system on the top of the engine and clean the ports from the bottom until air runs freely through the passages.
Before you get started, you will need some parts, supplies, and two custom made tools. The parts needed are: 1 SAI check valve, 6 gaskets that go between the heat exchanger and the head, 12 lock nuts to fasten the heat exchanger to the head, and two gaskets that go between the heat exchanger and the center portion of the exhaust. (Photo 2) A note when ordering these two gaskets: according to the dealer, the exhaust will have stamped on it either “Gillet” or “Bischoff”. It matters because each type takes a different gasket. You will also need a plastic or PVC ½ inch barbed fitting, available at any hardware store. (Photo 3)
http://forums.rennlist.com/upload/im001665_copy2.jpg (2)
http://forums.rennlist.com/upload/im001666_copy1.jpg (3)
The supplies you will need are a bottle of Techron, and a can of carb cleaner.
Besides the normal wrenches, sockets, and screwdrivers, you will need to make two special tools, which will be discussed later.
The first step is to remove the air cleaner assembly. In my case, it was very easy because of the cone-style K&N filter. (Photo 4)
http://forums.rennlist.com/upload/im001673_copy1.jpg (4)
Photo 5 is what you should be looking at with the air cleaner assembly removed.
http://forums.rennlist.com/upload/im001676_copy1.jpg (5)
The check valve is located between the forward-most intake runner and the chrome-looking pipe with two 90 degree bends in it. (Photo 6)
http://forums.rennlist.com/upload/im001677_copy1.jpg (6)
Next loosen the hose clamp and remove the rubber hose on top of the check valve. It’s ok to pry up on the hose with a screwdriver against the intake manifold, but DO NOT pry against the chrome-looking pipe, as it is relatively fragile. Prop the rubber hose out of the way.
The next step is to remove the check valve. This is easier said, than done. You will need to modify an opened end wrench to fit the check valve. I started with an old 15/16 “ wrench and, with a bench grinder, ground the opening until it fit the check valve. The two “fingers” that fit around the hexagon-shaped part of the check valve must also be ground down until they will fit between the upper portion of the check valve and the housing the check valve fits into. Finally, the wrench must be heated up and bent in two places. (Photos 7 & 8)
http://forums.rennlist.com/upload/im001675_copy1.jpg (7)
http://forums.rennlist.com/upload/im001690_copy2.jpg (8)
Reach the wrench in under the chrome-looking pipe and loosen the check valve. (Photo (9) Relax, the hard part is over.
http://forums.rennlist.com/upload/im001679_copy1.jpg (9)
Now it is time to make the second tool. Take the old check valve and separate the two halves. If you look closely, you’ll see that there is a seam in the middle where the edge of the top folds around the edge of the bottom. Separate the two halves by grinding off the folded over part. (Photo 10)
http://forums.rennlist.com/upload/im001667_copy1.jpg (10)
Now hammer the PVC barbed fitting into the bottom half of the check valve. (Photo 8)
Next screw the check valve/PVC fitting back into the hole it came out of. This is where you will pour in the Techron and blow in the compressed air. (Photo 11)
http://forums.rennlist.com/upload/im001683.jpg (11)
Remove the heater supply tubes. (Photos 12, 13 & 14)
http://forums.rennlist.com/upload/im001685_copy1.jpg (12)
http://forums.rennlist.com/upload/im001684_copy1.jpg (13)
http://forums.rennlist.com/upload/im001689_copy1.jpg (14)
Remove the heat exchangers. (Photos 15 & 16)
http://forums.rennlist.com/upload/im001687_copy1.jpg (15)
http://forums.rennlist.com/upload/im001686.jpg (16)
Now that the heat exchangers are off, you can look into the exhaust port of each head and actually see the SAI ports. These are holes about a quarter inch in diameter near the exhaust guide. Clean them out and clean the carbon from around the port. I stuck baling wire up into the port, sprayed carb cleaner into the port, scraped carbon from around the port with a flat screwdriver, and used a small wire brush. My ports were not plugged up so there wasn’t that much work to do. Your ports may require more work.
Pour some Techron into the PVC fitting. Don’t put too much in. It may splash back out. Blow air into the PVC fitting to help force the Techron through the passages. The PVC fitting is important because it allows the rubber end of the air nozzle a place to seal up against so that you can force the compressed air through the passages. (Photos 17 & 18)
http://forums.rennlist.com/upload/im001669.jpg (17)
http://forums.rennlist.com/upload/im001670_copy2.jpg (18)
Repeat this process until the compressed air blows out of all 6 of the SAI ports. If necessary, you can plug up five of the ports with used chewing gum, which will direct all of the compressed air to one port. I know this sound kind of hokey, but it worked. I’ve heard this described as kind of like plugging one nostril and blowing out the other. Work your way around until all of the nostrils, I mean ports, are clear. Blow compressed air through the system until the ports are dry.
Once everything is clean and dry, replace the heat exchangers using new gaskets and lock nuts. Replace the heat supply tubes.
Install the new check valve. Replace the rubber hose onto the top of the check valve and tighten the hose clamp. Feel up along the forward side of the rubber hose. There is something else in the hose just above the check valve that a much smaller rubber hose plugs into. (Look at Photo 12 just above the gray PVC fitting.) Make sure that the small rubber hose is hooked up. Mine came undone when I pushed the larger rubber hose out of the way.
Replace the air filter assembly, and you’re all done.
Good luck, Rob.
CLEANING SECONDARY AIR INJECTION PORTS
AND CHANGING SAI CHECK VALVE
This DIY provides a relatively easy way to clean the secondary air injection (SAI) ports and replace the SAI check valve. The car is a 96 993 with 40,000 miles. The car is stock except for a K&N cone air filter. The parts cost about $200. The job took about 6 hours, but this was done with the car on a lift. (Photo 1) I suspect doing this with the car on jack stands would take longer.
http://forums.rennlist.com/upload/im001671.jpg (1)
The basic procedure is to put solvent and compressed air into the SAI system on the top of the engine and clean the ports from the bottom until air runs freely through the passages.
Before you get started, you will need some parts, supplies, and two custom made tools. The parts needed are: 1 SAI check valve, 6 gaskets that go between the heat exchanger and the head, 12 lock nuts to fasten the heat exchanger to the head, and two gaskets that go between the heat exchanger and the center portion of the exhaust. (Photo 2) A note when ordering these two gaskets: according to the dealer, the exhaust will have stamped on it either “Gillet” or “Bischoff”. It matters because each type takes a different gasket. You will also need a plastic or PVC ½ inch barbed fitting, available at any hardware store. (Photo 3)
http://forums.rennlist.com/upload/im001665_copy2.jpg (2)
http://forums.rennlist.com/upload/im001666_copy1.jpg (3)
The supplies you will need are a bottle of Techron, and a can of carb cleaner.
Besides the normal wrenches, sockets, and screwdrivers, you will need to make two special tools, which will be discussed later.
The first step is to remove the air cleaner assembly. In my case, it was very easy because of the cone-style K&N filter. (Photo 4)
http://forums.rennlist.com/upload/im001673_copy1.jpg (4)
Photo 5 is what you should be looking at with the air cleaner assembly removed.
http://forums.rennlist.com/upload/im001676_copy1.jpg (5)
The check valve is located between the forward-most intake runner and the chrome-looking pipe with two 90 degree bends in it. (Photo 6)
http://forums.rennlist.com/upload/im001677_copy1.jpg (6)
Next loosen the hose clamp and remove the rubber hose on top of the check valve. It’s ok to pry up on the hose with a screwdriver against the intake manifold, but DO NOT pry against the chrome-looking pipe, as it is relatively fragile. Prop the rubber hose out of the way.
The next step is to remove the check valve. This is easier said, than done. You will need to modify an opened end wrench to fit the check valve. I started with an old 15/16 “ wrench and, with a bench grinder, ground the opening until it fit the check valve. The two “fingers” that fit around the hexagon-shaped part of the check valve must also be ground down until they will fit between the upper portion of the check valve and the housing the check valve fits into. Finally, the wrench must be heated up and bent in two places. (Photos 7 & 8)
http://forums.rennlist.com/upload/im001675_copy1.jpg (7)
http://forums.rennlist.com/upload/im001690_copy2.jpg (8)
Reach the wrench in under the chrome-looking pipe and loosen the check valve. (Photo (9) Relax, the hard part is over.
http://forums.rennlist.com/upload/im001679_copy1.jpg (9)
Now it is time to make the second tool. Take the old check valve and separate the two halves. If you look closely, you’ll see that there is a seam in the middle where the edge of the top folds around the edge of the bottom. Separate the two halves by grinding off the folded over part. (Photo 10)
http://forums.rennlist.com/upload/im001667_copy1.jpg (10)
Now hammer the PVC barbed fitting into the bottom half of the check valve. (Photo 8)
Next screw the check valve/PVC fitting back into the hole it came out of. This is where you will pour in the Techron and blow in the compressed air. (Photo 11)
http://forums.rennlist.com/upload/im001683.jpg (11)
Remove the heater supply tubes. (Photos 12, 13 & 14)
http://forums.rennlist.com/upload/im001685_copy1.jpg (12)
http://forums.rennlist.com/upload/im001684_copy1.jpg (13)
http://forums.rennlist.com/upload/im001689_copy1.jpg (14)
Remove the heat exchangers. (Photos 15 & 16)
http://forums.rennlist.com/upload/im001687_copy1.jpg (15)
http://forums.rennlist.com/upload/im001686.jpg (16)
Now that the heat exchangers are off, you can look into the exhaust port of each head and actually see the SAI ports. These are holes about a quarter inch in diameter near the exhaust guide. Clean them out and clean the carbon from around the port. I stuck baling wire up into the port, sprayed carb cleaner into the port, scraped carbon from around the port with a flat screwdriver, and used a small wire brush. My ports were not plugged up so there wasn’t that much work to do. Your ports may require more work.
Pour some Techron into the PVC fitting. Don’t put too much in. It may splash back out. Blow air into the PVC fitting to help force the Techron through the passages. The PVC fitting is important because it allows the rubber end of the air nozzle a place to seal up against so that you can force the compressed air through the passages. (Photos 17 & 18)
http://forums.rennlist.com/upload/im001669.jpg (17)
http://forums.rennlist.com/upload/im001670_copy2.jpg (18)
Repeat this process until the compressed air blows out of all 6 of the SAI ports. If necessary, you can plug up five of the ports with used chewing gum, which will direct all of the compressed air to one port. I know this sound kind of hokey, but it worked. I’ve heard this described as kind of like plugging one nostril and blowing out the other. Work your way around until all of the nostrils, I mean ports, are clear. Blow compressed air through the system until the ports are dry.
Once everything is clean and dry, replace the heat exchangers using new gaskets and lock nuts. Replace the heat supply tubes.
Install the new check valve. Replace the rubber hose onto the top of the check valve and tighten the hose clamp. Feel up along the forward side of the rubber hose. There is something else in the hose just above the check valve that a much smaller rubber hose plugs into. (Look at Photo 12 just above the gray PVC fitting.) Make sure that the small rubber hose is hooked up. Mine came undone when I pushed the larger rubber hose out of the way.
Replace the air filter assembly, and you’re all done.
Good luck, Rob.
Last edited by Rob Kwate; 10-11-2004 at 11:03 AM.
10-11-2004, 08:54 AM
#6
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Rennlist Member
Rennlist Member
Rob,
Excellent writeup.
I do have one question. Would a flare nut crows foot or a regular crowsfoot in the correct size like those in the photo below work to remove the check valve?
It sure sounds like doing this procedure at some sort of interval will keep the SAI passages from getting blocked real bad making it unnecessary to take more drastic measures to unclog them when and if they get clogged real bad.
Excellent writeup.
I do have one question. Would a flare nut crows foot or a regular crowsfoot in the correct size like those in the photo below work to remove the check valve?
It sure sounds like doing this procedure at some sort of interval will keep the SAI passages from getting blocked real bad making it unnecessary to take more drastic measures to unclog them when and if they get clogged real bad.
Last edited by Ron; 12-08-2014 at 09:53 AM.
10-11-2004, 09:25 AM
#7
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Rennlist Member
Rob, great job! Thanks for the such a detailed write-up. Can you check picture 15 and reupload it since it doesn't seem to be related to this diy?
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10-11-2004, 10:44 AM
#9
Rennlist Member
Thread Starter
Alexander: Thanks for the heads up on the picture. I don't know how that picture got in there. I've never seen that picture before. When my wife gets home from work tonight, I'll ask her to re-post the correct picture. I really am an idiot when it comes to computers.
Ron: The crow's foot wrench on the right side of your picture might work. It has to be fairly thin to reach in between the bottom of the check valve and the housing it screws into. Regarding the cut-off valve, I changed only the check valve, nothing else.
Ron: The crow's foot wrench on the right side of your picture might work. It has to be fairly thin to reach in between the bottom of the check valve and the housing it screws into. Regarding the cut-off valve, I changed only the check valve, nothing else.
10-11-2004, 11:01 AM
#10
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Rennlist Member
Rennlist Member
Rob,
The crows foot is 8.5 mm thick. About how thin would it need to be? It could be ground down so long as it did not need to be to thin.
Or how about the wrench in the photo below, in the correct size of course. It's a bicycle wrench and it's almost 2mm thick. It would be easier to bend since it's just made out of stamped steel. I don't know if it would be strong enough not being made of forged steel.
The crows foot is 8.5 mm thick. About how thin would it need to be? It could be ground down so long as it did not need to be to thin.
Or how about the wrench in the photo below, in the correct size of course. It's a bicycle wrench and it's almost 2mm thick. It would be easier to bend since it's just made out of stamped steel. I don't know if it would be strong enough not being made of forged steel.
Last edited by Ron; 12-08-2014 at 09:53 AM.
10-11-2004, 11:15 AM
#11
Check out this link ( www.systemsc.com/pictures.htm ). It provides additional pictures
of the SAI passages.
The thoroughness of the cleaning process and the extent of oil burning
will determine the long term effectiveness of the effort.
of the SAI passages.
The thoroughness of the cleaning process and the extent of oil burning
will determine the long term effectiveness of the effort.
Last edited by Lorenfb; 10-11-2004 at 12:13 PM.
10-11-2004, 11:18 AM
#12
Rennlist Member
Thread Starter
Update: My wife fixed picture 15 before she went to work. What a woman! She was concerned that I and the rest of the fruities on this board (as she calls us) wouldn't feel right until the picture was fixed.
Ron: The crow's foot wrench needs to be about 5mm thick. To check it, get a new check valve and put the wrench on it. You'll need to machine the wrench down until it does not cover any threads. I'm not sure if that makes sense, but look at picture 8 to see what I mean.
Ron: The crow's foot wrench needs to be about 5mm thick. To check it, get a new check valve and put the wrench on it. You'll need to machine the wrench down until it does not cover any threads. I'm not sure if that makes sense, but look at picture 8 to see what I mean.
10-11-2004, 06:49 PM
#14
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Best. Thread. Ever.
Rob and his lady rule!
Rob and his lady rule!
10-11-2004, 08:43 PM
#15
Rennlist Member
Originally Posted by Ron
Rob,
The crows foot is 8.5 mm thick. About how thin would it need to be? It could be ground down so long as it did not need to be to thin.
Or how about the wrench in the photo below, in the correct size of course. It's a bicycle wrench and it's almost 2mm thick. It would be easier to bend since it's just made out of stamped steel. I don't know if it would be strong enough not being made of forged steel.
The crows foot is 8.5 mm thick. About how thin would it need to be? It could be ground down so long as it did not need to be to thin.
Or how about the wrench in the photo below, in the correct size of course. It's a bicycle wrench and it's almost 2mm thick. It would be easier to bend since it's just made out of stamped steel. I don't know if it would be strong enough not being made of forged steel.
If you get a decent bicycle cone wrench (like a Park shop wrench) these can be surprisingly strong. In a pinch, I've used them to remove bike axel bolts without significant damage to the wrench. They only cost $7 or so.
-chris