32 Update: Finding A Rattle

Over 40,000 miles or so, the 32 had developed a little clunkle (“clunk” + “rattle”) that was driving me batty. The severity of the rattle was not dependant on the size of the bump, or how fast I was driving, or any other variables that I could vary. I could make it happen by jumping on the front passenger side frame rail, but not the driver side frame rail.

I tried to check the most obvious culprits first;

  • Are any exhaust brackets broken?
  • Are the emergency brake cables thwapping on the floor?
  • Is something clunking around under the seat? I have a power outlet built in to the front of the seat, and a while ago I noticed that the wires were not secured to anything and would click on the floor sometimes.
  • Is the heater/ A/C unit secure? Are all the vents secure in the dash?
  • Does the noise happen whether the windows are up or down? Sometimes the glass can clunk side-to-side when it’s down, if the whiskers don’t hold the glass as tight as the upper channel. Also, check the power window motor – maybe it’s come loose?

Moving to the outside, I checked every bolt I could see. Sometimes a click can be caused by a bolt that’s binding and just releasing at a certain point, or the threads are sort of riding at the edge of a hole. I checked the radiator support rod brackets against the firewall, I checked the air cleaner, I checked the headlights… I checked all those things again. Ready for the spoiler? When I was grinding the boxing plate welds where the engine mounts meet the frame, I must have sneezed at one point and taken off more than necessary. There was a tiny spot where the vibrations of the engine travelling through the mounts to the frame had worked a stress crack, and going over a little bump or jumping on the frame rail would cause the boxing plate to flex just enough to create a little click… kind of like a mason jar lid.

I was able to go over the spot with the tig, and now I’m no longer canning! It’s nice to be able to focus on something other than that little clunkle.

What are some noises that you’ve discovered in your hot rod?

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