PeachParts Mercedes-Benz Forum - View Single Post

patterson · #1 01-09-2002, 09:38 PM

I recently purchased a 1983 300D with 351,000 miles on it. I bought the car cheap because the engine is making an odd ticking noise that does not diminish with speed. The noise is about the same intensity idling as it is at speed. I have only driven the car home from the previous owner's home because of the noise. The PO says that is started on the way from Florida and he continued driving it and took it to our local mechanics and none of them could figure out what it was. So he continued driving it he claims to have driven it 10,000 miles since the noise started and it hasn't gotten any louder. The engine doesn't seem to have excessive blowby, doesn't smoke, has good oil pressure, and the PO said that it didn't use any oil.

I suspected that the problem was in the valve train somewhere so I pulled the valve cover and adjusted the valves, all of which were tight and some had no clearance. So the noise wasn't a loose valve. I started looking at the timing chain and it seemed to have about 6 degrees of stretch using the crank pulley as a guide. Also the guide rail at the tensioner seemed to not be aligned with the tensioner like it should be, there was actually a place worn in the arm by the tensioner pushrod where rail wasn't lined up like it should be. The guide rail is leaning back against the block. Would this make the noise that I am hearing some how? and What would have caused it?

I hypothesised that somehow the slack in the timing chain caused this somehow, but wouldn't the timing chain have broken in 10,000 miles of driving. I want to think that this is what is causing the noise and nothing deeper but I am not sure. Thank all of you for any help you can give.

Patterson