FIXED: Metallic rattle vibe at idle and during accel..

[BeerHat]

Hey just an FYI for those who have yet to track down and fix the annoying rattle coming from the rear at low speeds.

For reference, this is a 2008 X5 3.0si

We always had a rattle back there, dealer just looked the other way and said it was considered a normal-condition for the E70 chassis. Hmm. Really.

So yesterday I tracked the problem down to the oval/rectangular exhaust tip(s). They're loosely pressure fitted onto the pipe, then tack welded - small tack top and bottom. When the top tack weld broke free recently, the rattle became a lot worse.

It's actually a fairly easy fix.

Left and right exhaust exit tubes can be removed by loosening the clamp that holds them onto the exhaust. I had to drop the 2 rear exhaust hangers in order to get the clearance to actually pop the tubes off.

Once off, the problem was clear, and so was the solution. Took a 1/8" drill bit, drilled a through-hole into the tack weld, and then threaded in a small stainless screw to keep things tight. A short screw works best, so its a little less noticeable when looking into the tip from the back of the car.

Now, THAT fix only addressed the serious rattle, there was still a subtle tinny tink, buzzy kind of sound when tapping on it. I had a tube off-brand metal filler laying around, and so I used a popsicle stick to work a little bit into the gaps from the backside. Bolted everything back together, and let the tips cure for 24 hours. Worked a treat. Car sounds as tight as a drum.

This stuff's probably better than what I used, but the idea is the same:
3 1/2 Oz. Tube Liquid Metal Filler - Permatex (25909)

Best of luck!

Dan Keller
08 E70 X5 3.0si
96 E36 M3