In Reply to: Help with chain tensioner replacement posted by Chris Schrimsher on October 03, 2000 at 07:01:18:
Anyway, try resealing the two aluminum washers that seal the cylinder body and cap. The cap is 19mm and the body is 32mm (or is it 30mm?). I've found that the whole thing comes off if you try to take only the 19mm cap off. Then you can use a vise to hold the 32mm cylinder body (not too tight, though!!), and remove the cap. There are two aluminum washers, each a different size. Order new ones:
Get some Loctite 518 gasket sealer. It's a red goo that seals metal-to-metal surfaces. I put a thin coating on each side of both washers. It claims to seal gaps up to 0.010". It works great if you're reusing these "crush" washers, too.
Before reassembling, clean the piston and bore, and inspect for gouging or roughness. Check your spring, p/n 11 31 1 307 053, to make sure it isn't damaged, worn, or broken. You may want to replace it "while you're in there". I can't remember, but there may be a tiny ball-valve assembly inside the piston. Clean out the holes with a small wire and blast it with carb cleaner. If the valve malfunctions, the assembly may lose oil pressure (causing the rattle). If the cylinder or piston are damaged, they must be replaced as a unit, p/n 11 31 1 307 782. It's really expensive, about $120!!
First put the cylinder back in, don't forget to goop the new washer. Do not torque a lot, about 25lb-ft. Slide the piston in, making sure the slot in the nose of the piston is vertical. You can rotate the piston inside the cylinder to make sure it "locks" into the chain tensioner. Install the spring, and put the rear cap with new washer on. This is easier said than done. Be careful not to cross thread it. You may have better luck using a 19mm socket to hold the cap in your fingers. The spring is very long and pushes back with considerable force. It takes a lot of patience to get it threaded correctly. Once you get it, use a ratchet to put it on the rest of the way. Reinstall the nipple and o-ring. Have a beer. By now your hamstrings will be killing you.
Once everything's tight, get a syringe and a small length of 1/4" tubing. Loosen the nipple one turn. Fill the syringe with a couple ounces of oil and put the hose on the nipple. Squirt the oil into the tensioner. You may have to hold the hose ends to keep them from blowing off. If you were to start the car without pre-filling, the tensioner will take 15 minutes or more to refill with oil. You can avoid a lot of noise and annoyance by pre-filling it.
Good Luck, it's kind of a pain in the butt, but I did it as an inexperienced shade-tree mechanic.