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DIY - A6 3.2 Upper Timing Chain Tensioner Replacement
09-15-2015, 01:24 PM
#181
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3.2fsi
So i have now followed edge motors step by step and read all the comments on this forums. I have changed both my tensioners and tightened them 30, 60fp and then 90 degrees. I pulled out the crank-loking-tool snat the pin under the the car and was supposed to turn the engine to check if everything went smooth. It didnt... After turning 30 degrees i heard a pop sound, and i checked the drivers side chain which had gone all slack in some strange way. I´m thinking that the chain did not align correctly on the sprockets "teeths". What am i supposed to do now? with the chain all slaky, can i turn the engine back to TDC and redoo the procedure or am i out of timing? please help....
09-21-2015, 07:38 PM
#182
Great post. To help others that tackle this job, here are some added tips and my experience doing the job. This is not in any way intended to indicate that the post is not accurate or is incomplete but I wanted to answer a number of questions that I had that weren't spelled out completely in the original.
#1. Do not attempt this job without the cam locks and the crank position pin. Theoretically, if your engine was in time when you started and you could keep it in place you could install the cam adjusters back but it would be a miracle to get it back exactly as before without the locks. If you install the locks without the crank pin, you could get by, but not knowing if the crank is in time with the cams is a very big risk. I did find that my engine was perfectly aligned with the cam locks prior to installing the pin. The pin keeps things from moving when you are applying roughly 100lb feet of torque to the cam adjuster bolts for removing and reinstalling if your holder tool slips (and it will, see #4 below). Yes, you will have to remove the motor mount to get the crank pin in place but the potential for failure if you do without is not worth the risk.
#2 "pre tensioning" means lightly putting pressure(like the weight of your hand) on the cam adjuster holding tool with the bolts loose to remove any slack between the cam adjuster and the idler(drive) gear. It does not mean that the cam adjuster will move significantly. If you pull hard, you will cause the chain to ride up on the gear, compress the tensioner and could damage the seal. I did this and the tensioner failed to hold tension when I started the engine and then bent valves.
#3 If you have to recompress the tensioner piston to reinstall the pin,(in the case that you need to remove the new tensioner for some reason) you should take the piston out of the tensioner and depress the check valve with a wooden golf tee or some other non metallic item when compressing it. Do not just push the tensioner back to the original position while still in the housing. After compressing the piston and releasing it (you will have to release it to put it back into the housing) pour some clean oil into the housing and plug the hole on the back to keep the oil from running out. Re install the expanded piston back into the housing then slowly compress it to the fully compressed position and put the retaining clip back in. When you prepare to install it, remove what you plugged the hole with and install your gasket as you would normally. When you pull the pin during installation, this allows the piston to suck some oil when you release it so that you will have hydrolic pressure in addition to spring tension. If you just compress the piston without releasing the check valve, you will damage the seal and push the initial factory oil out of the unit and it will not survive the initial start up lag until oil gets to it. I ended up buying a second new tensioner as a result of my first error and had to replace all the valves on the head. Learn from my mistakes!
#4 The cam adjuster holding tool in most kits sucks. While it is designed to allow you to hold against your force when you are tightening or loosening the bolts, it barely grips and often just slips off. (yes, I know which direction to use for tightening and loosening) I found the a large pair of channel lock pliers (large enough to fit an oil filter) did a much better job of holding against the 60lb feet of torque before the additional 1/4 turn. (before I get flamed for being and cobb mechanic, yes it leaves marks but it is better than putting stress on the chain and and tensioners.)
#5 When you get the new tensioners installed and you are spinning the motor over 720 degrees to check to see if the cams remain in time and come back to the locked position, get someone to help turn the motor while you watch the cams move. They will make a snapping sound as the lobes clear the valves but this is normal. If the cams snap and then stay stationary, stop turning the engine as this means they likely skipped a tooth on the drive gear. You will now have to remove the cam adjusters and reinstall the tensioner. Most likely, you didn't follow #3 above and the spring tension was not enough to keep the chain tight. When I followed the procedure outlined in #3, the tension held.
#6 When you remove the valve covers, if you have a significant amount of sludge in and around the valve springs and cams, consider removing the oil pan and cleaning the sludge out of the pan and oil pickup screen. Even without a low oil pressure light, lower oil pressure and volume can cause the tensioners to lighten the tension enough to cause the rattle. Investing 2 hours and no parts (other than a fresh oil change and some cleaner) to improve oil flow might solve the issue without having to spend a day or two and 500+ worth of parts. I cannot prove beyond a shadow of doubt that this was my issue, but I suspect that the glop in my engine was the cause of the rattling if not the tensioners failing. Obviously if there is a lot of sludge, you may have to clean the pan more than once.
#7 When installing the crank pin, know that the hole in the pulley and the notch in the balancer roughly lines up with the seam from the upper oil pan and block or roughly 3:00 position looking at the pulley. Do not trust this description as your only input to know that the crank is in place. (USE THE PIN). Also, when the pin is installed, #2 cylinder will be TDC. Second or middle cylinder on the passenger side of the engine (in the US, anyway). I have verified this with a dental mirror looking into the access hole and the crank has a lovely little hole drilled in the web almost at the trailing edge when spinning clockwise. I also had the head off and could see the piston which extends beyond the block surface as they are domed pistons. Further, I used a long 1/4 in drive socket extension in the spark plug hole and found TDC by rotating the crank to note the highest position on this cylinder and the crank pin was aligned perfectly. To be clear, the manual states that the piston will be at TDC. They fail to mention which piston this is.
#8 When you take the motor mount off, you will need some way to hold the engine up. I used a 2x4 cut to length as a prop rod to the floor. (My floor jack leaks down) If you have a lift, you will need an engine support but that will really be in your way if it doesn't attach fairly far forward of the center of the engine.
Other notes:
The engine runs clockwise looking at it standing in front of the car.
The silicone sealer that comes in a Victor gasket kit is awesome stuff but if you use it for the upper covers, they will be difficult to remove.
Rotate the engine a few 720 degree cycles (more than one) to make sure the both sets of cams come up to the locked position and do so, together.
The job is not overly difficult but it is very time consuming to do properly. Do not take shortcuts, use the proper tools, read this and other posts carefully. As others have noted, by doing it yourself you should be saving at least 1,000.00 in labor and you get to know the car a little better.
#1. Do not attempt this job without the cam locks and the crank position pin. Theoretically, if your engine was in time when you started and you could keep it in place you could install the cam adjusters back but it would be a miracle to get it back exactly as before without the locks. If you install the locks without the crank pin, you could get by, but not knowing if the crank is in time with the cams is a very big risk. I did find that my engine was perfectly aligned with the cam locks prior to installing the pin. The pin keeps things from moving when you are applying roughly 100lb feet of torque to the cam adjuster bolts for removing and reinstalling if your holder tool slips (and it will, see #4 below). Yes, you will have to remove the motor mount to get the crank pin in place but the potential for failure if you do without is not worth the risk.
#2 "pre tensioning" means lightly putting pressure(like the weight of your hand) on the cam adjuster holding tool with the bolts loose to remove any slack between the cam adjuster and the idler(drive) gear. It does not mean that the cam adjuster will move significantly. If you pull hard, you will cause the chain to ride up on the gear, compress the tensioner and could damage the seal. I did this and the tensioner failed to hold tension when I started the engine and then bent valves.
#3 If you have to recompress the tensioner piston to reinstall the pin,(in the case that you need to remove the new tensioner for some reason) you should take the piston out of the tensioner and depress the check valve with a wooden golf tee or some other non metallic item when compressing it. Do not just push the tensioner back to the original position while still in the housing. After compressing the piston and releasing it (you will have to release it to put it back into the housing) pour some clean oil into the housing and plug the hole on the back to keep the oil from running out. Re install the expanded piston back into the housing then slowly compress it to the fully compressed position and put the retaining clip back in. When you prepare to install it, remove what you plugged the hole with and install your gasket as you would normally. When you pull the pin during installation, this allows the piston to suck some oil when you release it so that you will have hydrolic pressure in addition to spring tension. If you just compress the piston without releasing the check valve, you will damage the seal and push the initial factory oil out of the unit and it will not survive the initial start up lag until oil gets to it. I ended up buying a second new tensioner as a result of my first error and had to replace all the valves on the head. Learn from my mistakes!
#4 The cam adjuster holding tool in most kits sucks. While it is designed to allow you to hold against your force when you are tightening or loosening the bolts, it barely grips and often just slips off. (yes, I know which direction to use for tightening and loosening) I found the a large pair of channel lock pliers (large enough to fit an oil filter) did a much better job of holding against the 60lb feet of torque before the additional 1/4 turn. (before I get flamed for being and cobb mechanic, yes it leaves marks but it is better than putting stress on the chain and and tensioners.)
#5 When you get the new tensioners installed and you are spinning the motor over 720 degrees to check to see if the cams remain in time and come back to the locked position, get someone to help turn the motor while you watch the cams move. They will make a snapping sound as the lobes clear the valves but this is normal. If the cams snap and then stay stationary, stop turning the engine as this means they likely skipped a tooth on the drive gear. You will now have to remove the cam adjusters and reinstall the tensioner. Most likely, you didn't follow #3 above and the spring tension was not enough to keep the chain tight. When I followed the procedure outlined in #3, the tension held.
#6 When you remove the valve covers, if you have a significant amount of sludge in and around the valve springs and cams, consider removing the oil pan and cleaning the sludge out of the pan and oil pickup screen. Even without a low oil pressure light, lower oil pressure and volume can cause the tensioners to lighten the tension enough to cause the rattle. Investing 2 hours and no parts (other than a fresh oil change and some cleaner) to improve oil flow might solve the issue without having to spend a day or two and 500+ worth of parts. I cannot prove beyond a shadow of doubt that this was my issue, but I suspect that the glop in my engine was the cause of the rattling if not the tensioners failing. Obviously if there is a lot of sludge, you may have to clean the pan more than once.
#7 When installing the crank pin, know that the hole in the pulley and the notch in the balancer roughly lines up with the seam from the upper oil pan and block or roughly 3:00 position looking at the pulley. Do not trust this description as your only input to know that the crank is in place. (USE THE PIN). Also, when the pin is installed, #2 cylinder will be TDC. Second or middle cylinder on the passenger side of the engine (in the US, anyway). I have verified this with a dental mirror looking into the access hole and the crank has a lovely little hole drilled in the web almost at the trailing edge when spinning clockwise. I also had the head off and could see the piston which extends beyond the block surface as they are domed pistons. Further, I used a long 1/4 in drive socket extension in the spark plug hole and found TDC by rotating the crank to note the highest position on this cylinder and the crank pin was aligned perfectly. To be clear, the manual states that the piston will be at TDC. They fail to mention which piston this is.
#8 When you take the motor mount off, you will need some way to hold the engine up. I used a 2x4 cut to length as a prop rod to the floor. (My floor jack leaks down) If you have a lift, you will need an engine support but that will really be in your way if it doesn't attach fairly far forward of the center of the engine.
Other notes:
The engine runs clockwise looking at it standing in front of the car.
The silicone sealer that comes in a Victor gasket kit is awesome stuff but if you use it for the upper covers, they will be difficult to remove.
Rotate the engine a few 720 degree cycles (more than one) to make sure the both sets of cams come up to the locked position and do so, together.
The job is not overly difficult but it is very time consuming to do properly. Do not take shortcuts, use the proper tools, read this and other posts carefully. As others have noted, by doing it yourself you should be saving at least 1,000.00 in labor and you get to know the car a little better.
09-28-2015, 05:05 PM
#183
occhis,
No intention to sound condescending or disrespectful in any way. You and possibly everyone that has ever worked on an internal combustion engine assumes that TDC means number 1 cylinder. On this engine the middle cylinder on the passenger side (US cars)no matter what number you assign to it is at TDC with the crank pin installed, period. The engine will not go together any other way. I mention that in my tips because it is totally non intuitive. I had well over 100 hours in the project I had and did valve replacements on both cylinders due to loss of oil pressure. To do anything else (setting it up with the valves locked in the jig without the middle cylinder at TDC) is a guarantee for bent valves.
No intention to sound condescending or disrespectful in any way. You and possibly everyone that has ever worked on an internal combustion engine assumes that TDC means number 1 cylinder. On this engine the middle cylinder on the passenger side (US cars)no matter what number you assign to it is at TDC with the crank pin installed, period. The engine will not go together any other way. I mention that in my tips because it is totally non intuitive. I had well over 100 hours in the project I had and did valve replacements on both cylinders due to loss of oil pressure. To do anything else (setting it up with the valves locked in the jig without the middle cylinder at TDC) is a guarantee for bent valves.
12-23-2015, 02:57 PM
#185
12-28-2015, 04:07 PM
#187
The first time was the job where I pulled the trans and did all the guides on all four chains. I also built a special jig for my transmission jack (figuring I'd be doing this job more than once). All told, probably at least 50 hours.
12-29-2015, 11:49 AM
#189
While it's certainly much quicker and easy to do only the uppers, "a couple of hours" is wildly optimistic, IMHO. Maybe a couple of hours each side...
01-28-2016, 08:50 AM
#190
AudiWorld Newcomer
attempting mine and ran into some ???
so when I pulled the passenger side timing cover I found the intake cam gear bolt had come loose which of course impacted timing... additionally all the exhaust rocker arms where no longer in place but laying along side each valve.
I had an Audi tech explain that the only way rocker arms can some off is if valve is bent (was thinking it was more related to cam being out of position). I was also told the valve springs don't have enough strength to hold the valve closed on their own ( I thought that was the job of the spring??) ... so now I am believing I need to pull the head and replace all exhaust valves ???
any advice would be appreciated....
thanks
Doug
I had an Audi tech explain that the only way rocker arms can some off is if valve is bent (was thinking it was more related to cam being out of position). I was also told the valve springs don't have enough strength to hold the valve closed on their own ( I thought that was the job of the spring??) ... so now I am believing I need to pull the head and replace all exhaust valves ???
any advice would be appreciated....
thanks
Doug