My 2000 D2 (owned since new) is emitting something between a chatter and a light clatter (definitely not a clanking) when in gear, but only between 1750 and 2000 rpm. Otherwise, at higher or lower rpm, it runs very smoothly.

There is no noise when I simply rev the engine without it being in gear. (The engine was an OEM replacement installed under warranty in 2009, and has about 76k miles on it. The car as a whole has about 170k.)

There is also no noise until the engine reaches operating temperature.

The noise occurs whether I am giving it gas or not, just as long as the rpm are between 1750 and 2000 rpm. Also, it occurs regardless of what gear it is in.

It doesn't sound like the noise is coming from somewhere internal to the engine itself, but it is coming from somewhere forward of where I sit.

All fluids replaced in 2023. Drive shaft zerk fittings lubed last week (it is a Lucky 8 aftermarket unit installed around 2018-19). Replaced radiator, thermostat and coolant tank last week, and this had no effect on the noise.

Valve cover gaskets, last replaced in 2018, have reached the point of leaking again, and I will have the job done again later this month.

Any thoughts?

 

The propshafts (front and rear) are the usual first suspects... so perhaps the motor and transmission mounts deserve investigation.

 

It sounds like the timing chain is original. Could it be stretched enough to cause your chatter?

 

Sorry, I reread your post and the engine doesn’t have a lot of miles on it.

 

Sounds like a driveshaft to me honestly. Mine did that too but only on the gas leaving a stop sign.