HELP!!! Knocking Sound

[Roadhouse_1]

I have an 04 SR5 4WD (no mods). Ever since I bought it, it's been making this knocking sound. I can't tell exactly if it's coming from the front or rear, but I'm sure it's underneath somewhere cause I've felt it in my feet when driving. The noise is very random, and very loud. It doesn't coincide with cracks or bumps in the road, so I wasn't thinking suspension. I took my jack and tools out of the back to eliminate that (cause some on here suggested that for other noise questions). I took it to the dealer and they couldn't figure it out either. It seems worse now that it's getting colder. I didn't drive it for a week and now it's really bad. It doesn't affect my driving other than annoyance. So now what? Bearings, joints, other? Any help would be great. Oh and I am running the correct fuel. Thanks

 

[CJ3Flyr]

Could it be loose bolts on the engine mounts or on the rear of the t-case? Does it coincide with acceleration and deceleration in any way? The fact it doesn't coincide with bumps doesn't eliminate the possibility of an exhaust hangar either. I'd put it in R, hold the brake and push the gas for a second then shift to D and do the same. If that gets it to 'pop' then it's most likely loose/damage motor mounts or t-case mount on the rear crossmember.

Now I offer that assuming you've had the driveshaft and u-joints greased regularly. I am also assuming you've looked under there and all of your bottom shock/strut bolts are tight.

Good luck!
:cheers:

 

[spo0587]

Mine does the same thing, and I got my looked at. The mechanic determined that it was my isolator bushings. These are inside of your coil spring, and they help cushion the frame from the body I believe. However, you can only hear mine when you go over bumps. I decided it wasn't worth fixing them because of the cost (you have to buy the coil springs, and bushings. They come in a kit, therefore you can't buy them separately). Also it doesn't hurt the truck any, as long as you still have some. When the rubber gets old and cracked, it moans a bit. Hope this helps!