My 82 240D has recently started making a new noise in the past 1000 miles or so and I can only hear it driving with the windows up (ac on or off).
Ticking sound made with engine hot or cold. Primarily on throttle and most noticeable at lower engine speeds. Does not get louder if i floor the throttle, I can also hear it revving in neutral or park. When i listen to the motor with the hood up or driving against a wall for example it sounds the same as it always has!

I have done the following:

• swapped the injectors with another known good set ( have a tester)

• pulled the vacuum pump and checked the roller bearing and assembly - all tight

• Checked the cam the vacuum pump roller bearing rides on in the engine - looks good and very tiny amount of play if i pull on the bolt head with a set of pliers.

• Checked the oil pump drive bearing - looked ok

• run a diesel purge (sound does not go away running the motor straight on purge)

• Adjusted valves - i do this every year and none were really out of spec

• Checked timing chain - very tight (recently installed a new tensioner)

• Disconnected ac compressor and ps pump and ran engine without them to try and isolate sound - no difference


I am not trying to drive myself crazy, and understand these old diesels make noises. Thing is I bought this car at 140k miles and it now has 185k miles so I am very used to the sounds the motor makes. Oil has always been changed every 3k by myself and the PO and never run low. I am really expecting this motor to have alot of life left!

This one is definitely a new sound. I also realize these motors can make noises for thousands of miles and be perfectly fine. Just curious if anyone has any input.


Videos:

inside vehicle
engine compartment