Hi everyone,

So - I've had my 1984 300D for about a month now, and since buying it I have noticed a weird, somewhat-unpredictable noise. The noise sounds like a sort of metallic "clunk" but more akin to the kind of "reverberating" "boingggggg" noise you might hear if you hit a large spring with a hammer.

I've heard the noise under the following conditions:

1) Hitting a speed bump a little too fast
2) Going over a speed bump while cornering (again a bit too fast)
3) If the car's weight shifts quickly while cornering
4) Hitting cracks or other obviously small, sudden bumps in the road.

Maybe more importantly, these are the only sorts of circumstances under which I've heard the noise. The car certainly feels like it handles normally - it doesn't pull or make other strange noises.

Actually - it does make one other noise I cannot pinpoint and that is, if I'm on the freeway, I begin to notice an odd, thrumming sort of low hum. The hum is periodic, and the intensity of the hum increases and diminishes over the course of about a second. Like a sort of "whooom....whooom...whoom". I only ever hear this if I'm going over about 90km/h, and It starts to become really apparent to me if I am over about 110km/h. I am not sure this is related to my first noise, but it might not hurt to ask. The noise is a pretty "low-frequency" sounds, so it is difficult for me to tell where it originates. So far, I know I hear it with the tranny in D, and also with the tranny in N (no change in the noise at all between those two)

Anyway, I am thinking maybe the first place for me to start is to check the shock mount, and maybe the bushings. Anything else I should be considering?

Thanks in advance!