Could be a bad motor mount, had that same issue with my 350 (clunk clunk/ rumble rumble sound over certain bumps). Turns out it was a bad motor mount.

Everyone else has mentioned the sways and links so I thought I'd just throw this out since it doesn't say in your signature what springs/shocks/coilovers you may have if any.

A blown shock can make that clunk noise too from bottoming out. Check for blown seals or oil, or you can see if it compresses too easy (but you have to take it off for that). Also check the center nut on the shock shaft and the 3 upper nuts that hold the top mount on.

yah if it's not the endlinks i would look at the engine mount and strut mounts, tower bar, and struts themselves.

... then later find out it's just a loose battery. :D

Do you run your A/C a lot?

I'm not sure about the 370z but past Altimas had a horrible A/C clutch. After a while it would start clunking every time the compressor turned on.

would suck if his oil drain plug was rolling around on the cover. :D

Loving the speculation!

Jacked her up, took her cover off, and had a look up her skirt. And the problem was....nothing. Saw that one coming. Strut mounts, sway mounts, engine mounts, end links, essentially every bolt I could find under there was a-OK. Oil drain plug was where it should be. I keep the A/C compressor off with the cool temps as the accessory fan makes the oil cooler overly effective during the fall/winter/spring.

Either I'm hearing things or this issue will present itself later. Regardless, I'm going to add some Whiteline end links to my spring to-do list.

I'll revive this thread from the dead sometime down the road if I ever locate the issue. Thanks to everyone for their input.

I had some noises over bumps and it was the grease on the sway bar bushings that had dried up. I re-lubed the inside of the bushing and no more noise. It was a squeaky clunk noise.

Funny you mention that. I just placed an order for a grease gun and some over-priced Hotchkis special silicone lube. They did look a bit dry. Anyone else tired of taking the undertray off the car?

^^yes. Wish it was like the titan, remove 2 screw sand 2 bolts and loosen the back 2 bolts.

i'm no gear head no offence. but once i had a 97 vette and had the same noise. it ended up being something about the calipers.

It's pretty impressive how broad the differential diagnosis is for such a general sound. Brakes have been working nicely but I'm starting my 6-pot AP Racing caliper fund since my Akebono dust boots are fried and I figure they'll die eventually.

AND THE WINNER IS...

Sway bar bushings.

Lubed them with the Hotchkis silicone goo and the sound is gone. Thanks for all the help. I'll have to make a 4-5 month schedule of lubing those things. Such a nasty sound when the bushings are dry.

Do I win a prize? LOL.

I used a different grease when I re-lubed mine, seemed to last longer than the Hotchkis stuff.

Your prize is that I will bother you first when I have my next problem :).

Which grease are you using? I was looking around online for silicone-based greases but they're tough to find. I did see that people get some plumbing stuff from Ace that is silicone based and is much cheaper. Hotchkis really screws us on the price.

A-HA! :tup: