In Reply to: here you go... posted by Ritter on October 27, 2001 at 08:21:44:
Here is a step by step process for changing the timing chain tensioner on the E30 M3. This is being done with a late model E36 M3 tensioner that is of a hydraulic design. This design contains no spring and therfore provides consistant chain tension, even on cold starts. Thanks to our German friend Karim for this upgrade suggestion.
Order parts #11 31 1 405 081 (tensioner), and # 07 11 9 963 418 (metal seal ring). The tensioner is 2 pieces which consists of a cylinder/pistion that slides into a threaded cap.
This is best done with a cool/cold engine.
1. Remove the windsheild washer fluid tank located on the right side of the engine compartment
2. Locate the tensioner on the engine block. It is above the A/C compressor just in front of the exhaust header. With a rag clean the area around the tensioner.
3. Remove this tensioner assembly. The Original design has 3 different parts that bolt together. On the very end is a small nipple, then a middle section (with a 19mm hex ) and then the section which threads into the block (with a 32mm hex). Use a deep 19 mm deep socket and fit it over the middle section of the tensioner assembly. Break the torque on this piece and unthread the part(s). (when I did this it loosened the whole assmebly not just the middle section.) I unthreaded the assembly by hand and on the last turn it all popped out because of the spring inside. I had a rags placed under and around this area to catch any oil and help absorb the force of the spring releasing. Remove all the parts. Depending on how yours came off you might need to use a 32mm socket to remove the last section that bolts into the block.
4. Installing the new tensioner. Take the cylinder/pistion piece. It has a blunt end and a grooved end. Press on the grooved end to work the piston action. Mine was quite stiff at first. After working the movement a few times the pistion released and extended another 1/4" or so. It seemed like the range of movement was about 1/2". Fit the metal seal ring over the threaded section of the cap so it rests at the base. Take this cylinder/pistion and insert the blunt side into the tensioner cap about half way. Hold it in place with the side of your finger. Guide this assmebly into the hole in the block. The groove on the end of the tensioner goes in vertically and fits around the tensioner rail in the engine. It does not matter which side of the pistion faces up. There is no reference mark on this new piece. Thread the cap in by hand. I was able to thread it in almost all the way by hand. If you can't thread it in then the groove on the end of the pistion is not fitting in right. Take a 32mm socket drive, fit it on to the cap and torque it down to 29 lb/ft (as suggested by the Koala repair CD) I used a 1" extension on my socket driver and this provided enough lenght to fit over the cap and clearence for the torque wrench handle movement.
5. Now start it up... the chain should not rattle. If it does then shut the engine off and remove the tensioner assembly. Check the pistion movement of the cylinder. As stated before, mine was quite stiff and was not fully extending. I worked the pistion action by hand several times and noticed the action became more pronounced. I am guessing about 1/2" movement total but I did not measure it. I re installed it and it worked fine after that.
6. Replace the windsheild washing fluid tank and you're done.
This is about a 20 - 30 minute process if you don't have any glitches. I am very happy with the results. My engine sounds tighter/quieter and seems to run smoother. An $83 investment and worth every cent!!!
Hope this helps anyone interested in this install.
Best of luck...Chris (C///MR)
P.S. Thanks again Karim for this great tip!