DIY Chain Tensioner Pad Replacement 944S2
11-07-2010, 01:10 PM
#1
Instructor
Thread Starter
DIY Chain Tensioner Pad Replacement 944S2
Let us begin shall we?
First and foremost, the area in question is at the heart of the beast; the valve cover. After disconnecting the battery (safety first), remove the black plastic protective cover that conceals the fuel rail. There are four (4) tabs (2 tabs on each side) that hold it in place. You can use a screwdriver to gently apply pressure to each pad or you can squeeze the cover on each side of a tab to easily remove it. Once the fuel rail cover is removed the fuels rails will be exposed.
The next step is disconnect the two (2) fuel lines from the fuel rail. Place a rag under the area where the fuel lines attach to the fuel rail to absorb any fuel that may spill out when you disconnect them. To disconnect the fuel line closest to the front of the car, use a 17mm open-end wrench to hold the fuel rail nut and a 19mm open-wrench to turn and loosen the fuel line nut. As you loosen the fuel line, it is extremely important to hold the fuel rail nut and prevent it from turning. Failing to do so and you can snap the fuel rail nut which is welded onto the fuel rail (this would be a bad thing). Next, disconnect the fuel line closest to the firewall. Reverse your wrenches - the fuel line is a 17mm and the fuel rail nut is a 19mm. Again, remember the drill, hold the fuel rail nut to prevent it from turning, as you loosen the fuel line. If not, you run the risk of snapping the fuel rail nut from the fuel rail. Once the fuel lines were disconnected, I tied them together and pulled them out of the way by wiring them to the hood's passenger side gas shock. With the fuel lines out of the way, removal of the valve cover will now be facilitated.
Using a # 2 Phillips head screwdriver, remove the two (2) plastic spark plug wire holders that secure the wires to the valve cover. After removal of the spark plug wire holders, pull the spark plug wires away from the spark plugs by simply pulling from the base of each spark plug wire. A smooth and even pull should do the trick. Using a a 5mm Allen socket, remove the thirteen (13) valve cover bolts that secure the valve cover to the cylinder head. After breaking the bolts loose, use a T-handle wrench to quickly remove them. Now, remove the valve cover and behold the beauty underneath and the target of the install.
As a precautionary measure, and prior to removing the Camshaft Chain Tensioner, stuff rags into each of the spark plug chambers/holes, as well as the oil passages - you don't want anything (small bolts, washers, etc.) dropping into those areas. Next using a 6mm Allen socket, remove the two (2) J-tube bolts that secure it to the camshaft chain tensioner and oiling port. I used a claw tool to extract the upper and lower J-tube bolts -it's tight in there. Double check your work and ensure that none of the J-tube washers remain behind - I fished one out using a pick. After removing the J-tube from the cylinder head, note the orientation of the washers - there are two (2) per banjo type bolt. I replaced the washers with new ones to ensure a good seal upon install.
Next is the removal of the camshaft chain tensioner, so that the tensioner pads can be inspected and replaced. In order to do so, downward pressure most be exerted on the upper tensioner pad to counteract the upward force of the hydraulic cylinder that it is seated onto. While doing so, a finishing nail or something with a similar diameter (I used 2 sections of coat hanger that I snipped with wire cutters) must be inserted into two (2) small holes located on the side of the camshaft chain tensioner. This will keep the hydraulic cylinder compressed and provide the slack in the chain that is needed to remove the camshaft chain tensioner. I used the palm of my hand and pushed down hard on the chain that rests upon the uppper tensioner pad. As I did so, I inserted a section of coat hanger into each hole. I inserted each coat hanger deep enough, so that they just contacted the chain. Next, remove the two (2) camshaft tensioner bolts, using a 5mm Allen socket. Remove the camshaft chain tensioner - finally!
Next, I placed the camshaft chain tensioner in the jaws of a bench vice in order to compress the hydraulic cylinder, so the coat hanger inserts can be removed. Remember to use the smooth side of the jaws, so the pads aren't damaged - you'll want to inspect the pads in their original condition. Take the camshaft chain tensioner off the vice and remove the top pad by simply sliding it out. Note the orientation of the pad - it is specific. The new top pad sildes right in. Again, note the orientation of the pad. Using a # 1 Phillips screwdriver, remove the two (2) screws that hold the bottom pad in place. After removing the two (2) screws, replace it with the new pad by reversing the process. Now that both pads have been replaced, it's back to the bench vice. Remember to place the camshaft chain tensioner in the smooth jaws of the vice - you don't want to damage the new pads. Insert the coat hanger sections (or whatever you use) into the two (2) holes located on the camshaft chain tensioner. Insert just enough of the coat hangers (or whatever you use) to keep the pad in the compressed position, yet allow clearance for the chain upon installation. Remove the camshaft chain tensioner from the vice and install it from whence it came!
Words of caution: Use great care not to over torque the camshaft chain tensioner bolts. Unfortunately, it takes very little effort to strip out the threads to the aluminum head (they're soft as hell). The factory manual specifies tightening torque of ten (10) Nm or seven and a half (7.5) ft lb. The same torque specs apply to the chain tensioner banjo bolt. Triple check the torque setting on your torque wrench - it's helpful to have another set of eyes when you do so. Place close attention and be very careful. Not checking is a mistake that you don't want to make.
Installation is the reversal of removal. Remove the coat hanger sections (or whatever you use). Reinstall the J-tubes, etc. Remove the rags that were stuffed into the spark plug holes and the oil passages. Check to make sure that you haven't left any tools on the cylinder head or dropped any foreign objects into the head before you button things up.
BTW, don't forget to check your valve cover gasket before you finish up the install. Mine was torn and needed to be replaced. I put a tab of silicone sealant on each corner of the valve cover to keep the gasket in place and ease reassembly. Don't over torque the valve cover bolts (remember the head is aluminum and the threads can be easily striped).
Hope I wasn't long-winded. Lastly, thanks to my beautiful wife for being my photographer and indulging my 944 madness (chicks dig guys that are resourceful and can turn a wrench).
First and foremost, the area in question is at the heart of the beast; the valve cover. After disconnecting the battery (safety first), remove the black plastic protective cover that conceals the fuel rail. There are four (4) tabs (2 tabs on each side) that hold it in place. You can use a screwdriver to gently apply pressure to each pad or you can squeeze the cover on each side of a tab to easily remove it. Once the fuel rail cover is removed the fuels rails will be exposed.
The next step is disconnect the two (2) fuel lines from the fuel rail. Place a rag under the area where the fuel lines attach to the fuel rail to absorb any fuel that may spill out when you disconnect them. To disconnect the fuel line closest to the front of the car, use a 17mm open-end wrench to hold the fuel rail nut and a 19mm open-wrench to turn and loosen the fuel line nut. As you loosen the fuel line, it is extremely important to hold the fuel rail nut and prevent it from turning. Failing to do so and you can snap the fuel rail nut which is welded onto the fuel rail (this would be a bad thing). Next, disconnect the fuel line closest to the firewall. Reverse your wrenches - the fuel line is a 17mm and the fuel rail nut is a 19mm. Again, remember the drill, hold the fuel rail nut to prevent it from turning, as you loosen the fuel line. If not, you run the risk of snapping the fuel rail nut from the fuel rail. Once the fuel lines were disconnected, I tied them together and pulled them out of the way by wiring them to the hood's passenger side gas shock. With the fuel lines out of the way, removal of the valve cover will now be facilitated.
Using a # 2 Phillips head screwdriver, remove the two (2) plastic spark plug wire holders that secure the wires to the valve cover. After removal of the spark plug wire holders, pull the spark plug wires away from the spark plugs by simply pulling from the base of each spark plug wire. A smooth and even pull should do the trick. Using a a 5mm Allen socket, remove the thirteen (13) valve cover bolts that secure the valve cover to the cylinder head. After breaking the bolts loose, use a T-handle wrench to quickly remove them. Now, remove the valve cover and behold the beauty underneath and the target of the install.
As a precautionary measure, and prior to removing the Camshaft Chain Tensioner, stuff rags into each of the spark plug chambers/holes, as well as the oil passages - you don't want anything (small bolts, washers, etc.) dropping into those areas. Next using a 6mm Allen socket, remove the two (2) J-tube bolts that secure it to the camshaft chain tensioner and oiling port. I used a claw tool to extract the upper and lower J-tube bolts -it's tight in there. Double check your work and ensure that none of the J-tube washers remain behind - I fished one out using a pick. After removing the J-tube from the cylinder head, note the orientation of the washers - there are two (2) per banjo type bolt. I replaced the washers with new ones to ensure a good seal upon install.
Next is the removal of the camshaft chain tensioner, so that the tensioner pads can be inspected and replaced. In order to do so, downward pressure most be exerted on the upper tensioner pad to counteract the upward force of the hydraulic cylinder that it is seated onto. While doing so, a finishing nail or something with a similar diameter (I used 2 sections of coat hanger that I snipped with wire cutters) must be inserted into two (2) small holes located on the side of the camshaft chain tensioner. This will keep the hydraulic cylinder compressed and provide the slack in the chain that is needed to remove the camshaft chain tensioner. I used the palm of my hand and pushed down hard on the chain that rests upon the uppper tensioner pad. As I did so, I inserted a section of coat hanger into each hole. I inserted each coat hanger deep enough, so that they just contacted the chain. Next, remove the two (2) camshaft tensioner bolts, using a 5mm Allen socket. Remove the camshaft chain tensioner - finally!
Next, I placed the camshaft chain tensioner in the jaws of a bench vice in order to compress the hydraulic cylinder, so the coat hanger inserts can be removed. Remember to use the smooth side of the jaws, so the pads aren't damaged - you'll want to inspect the pads in their original condition. Take the camshaft chain tensioner off the vice and remove the top pad by simply sliding it out. Note the orientation of the pad - it is specific. The new top pad sildes right in. Again, note the orientation of the pad. Using a # 1 Phillips screwdriver, remove the two (2) screws that hold the bottom pad in place. After removing the two (2) screws, replace it with the new pad by reversing the process. Now that both pads have been replaced, it's back to the bench vice. Remember to place the camshaft chain tensioner in the smooth jaws of the vice - you don't want to damage the new pads. Insert the coat hanger sections (or whatever you use) into the two (2) holes located on the camshaft chain tensioner. Insert just enough of the coat hangers (or whatever you use) to keep the pad in the compressed position, yet allow clearance for the chain upon installation. Remove the camshaft chain tensioner from the vice and install it from whence it came!
Words of caution: Use great care not to over torque the camshaft chain tensioner bolts. Unfortunately, it takes very little effort to strip out the threads to the aluminum head (they're soft as hell). The factory manual specifies tightening torque of ten (10) Nm or seven and a half (7.5) ft lb. The same torque specs apply to the chain tensioner banjo bolt. Triple check the torque setting on your torque wrench - it's helpful to have another set of eyes when you do so. Place close attention and be very careful. Not checking is a mistake that you don't want to make.
Installation is the reversal of removal. Remove the coat hanger sections (or whatever you use). Reinstall the J-tubes, etc. Remove the rags that were stuffed into the spark plug holes and the oil passages. Check to make sure that you haven't left any tools on the cylinder head or dropped any foreign objects into the head before you button things up.
BTW, don't forget to check your valve cover gasket before you finish up the install. Mine was torn and needed to be replaced. I put a tab of silicone sealant on each corner of the valve cover to keep the gasket in place and ease reassembly. Don't over torque the valve cover bolts (remember the head is aluminum and the threads can be easily striped).
Hope I wasn't long-winded. Lastly, thanks to my beautiful wife for being my photographer and indulging my 944 madness (chicks dig guys that are resourceful and can turn a wrench).
Last edited by Izzy Does It; 12-15-2010 at 12:41 AM.
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NiceSharky (07-18-2019)
11-07-2010, 02:45 PM
#5
Drifting
Extremely nice write up!
Small cautions that just worry me, the use of the vice to compress the new pads worries me. I believe I used all my hand power to compress them and another person insert the small wire. I didn't want to risk pre-mature cracks.
Also, the two bolts that hold the tensioner down are generally stripped out or will strip when you re-install. You can use a longer bolt here as well (factory tapped the holes for longer bolts, but used shorter?? I forget the size, so please measure accurately!!). I then put blue loctite on the threads and also used lock washers. Both of my holes had severely ruined threads at the top and my tensioner is held on rock solid now!
Small cautions that just worry me, the use of the vice to compress the new pads worries me. I believe I used all my hand power to compress them and another person insert the small wire. I didn't want to risk pre-mature cracks.
Also, the two bolts that hold the tensioner down are generally stripped out or will strip when you re-install. You can use a longer bolt here as well (factory tapped the holes for longer bolts, but used shorter?? I forget the size, so please measure accurately!!). I then put blue loctite on the threads and also used lock washers. Both of my holes had severely ruined threads at the top and my tensioner is held on rock solid now!
11-07-2010, 03:15 PM
#6
Instructor
Thread Starter
CarbonRevo, thanks for you input and contribution. You pointed out important and valuable points. After I pulled the camshaft chain tensioner out of the vice, I inspected it for any damage but none was apparent - the pad appears rather robust. Your concern is well taken though. I used due care and did not gorilla the vice beyond the tensioner's stopping point. Your method is an outstanding alternative with no chance of causing damage to the pad. You are correct about the length of the factory bolts (go figure the factory, huh?). Great advice on how to go about repairing the damaged threads and reinforcing the work with blue loctite and lock washers. Make it bulletproof or go home! Thanks again for making this DIY thread better.
11-08-2010, 03:47 PM
#7
Burning Brakes
Join Date: Dec 2009
Location: Montreal, Quebec, Canada
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A small note.
When you open up the valve cover the old gasket may stick and fall apart. The PO of my car felt the need to clean the surface of the head with an abrasive pad. Presumably because the old valve cover gasket stuck to the head.
DON'T use an abrasive pad on an aluminum head as it will scar the aluminum forever. I believe the best way to remove the gasket if it is stuck it with a razor blade and allot of patience.
Luckily the ruts in my head are not deep enough to cause leaks once a new gasket was installed.
When you open up the valve cover the old gasket may stick and fall apart. The PO of my car felt the need to clean the surface of the head with an abrasive pad. Presumably because the old valve cover gasket stuck to the head.
DON'T use an abrasive pad on an aluminum head as it will scar the aluminum forever. I believe the best way to remove the gasket if it is stuck it with a razor blade and allot of patience.
Luckily the ruts in my head are not deep enough to cause leaks once a new gasket was installed.
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04-20-2011, 05:48 PM
#10
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Join Date: Mar 2011
Location: California
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Very nice write up. I was under the impression from talking with another s2 owner that I would need to remove the cams! This makes the job much less intimidating. Thank you for your work! 
04-20-2011, 10:09 PM
#11
Instructor
Thread Starter
04-20-2011, 10:17 PM
#12
Instructor
Thread Starter
Glad I could be of help. Just be mindful of the torque specs. Triple check them. I have a photo DIY regarding repairing fan resistor wiring that I have delayed posting (overworked and underpaid). You'll want to check that one out as well. If you have any question don't hesitate to ask. Good luck and enjoy turning your own spanners.
10-04-2011, 07:18 PM
#14
Rennlist Member
