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  1. #1

    Default Recently fixed truck rattling in engine compartment.

    So I took it in and had a plugged catalytic converter fixed, as well as a fuel pump on it's last legs. The truck sounds a bit louder, clearer and healthier (I assume because the cats no longer clogged, tell me if this is right or wrong). However, in the lower engine compartment is a sound I'd never heard before. Under idle and at load, it sounds like a bunch of paint cans (sort of a hollow sound) rattling all at once. It drives great, which I'm grateful for. But I was wondering what during the course of fixing those two things, might have caused a rattling sound.

    For the record, not sure if it's relevant, but I had to drive it a little bit while it was having it's problems (multiple cylinder misfires). Now I'm spooked something is damaged from my driving it.

    Any ideas to soothe my mind would really help.

  2. #2


    There are heat shields on the trucks to keep unwanted heat out of certain areas of the vehicle.

    These shields are just pieces of metal sitting between the heat source and the area to be protected.

    The exhaust is one of these heat sources, check the area around the cat and the pipes in front of the cat. One of the heat shields is probably lose.

    '09 Avalanche LTZ - Black
    '05 Envoy XL (sold)

  3. #3


    Thanks I'll take a look. Also, it's a 99 Silverado, v6. I'm a tad embarrassed I somehow forgot to mention that.

    If infact, it's one of these heat shields that is loose, is that a major problem? I mean if I drove it this way, is it going to explode?

  4. #4


    Nah if it's just a heatshield there shouldnt be any lasting affects after it's repaired.
    Hardest part will be trying to figure out how to secure the heatshield.

  5. #5


    Wow. I just started it and had someone else step on the gas...I have two Cats on and the left one (I guess it would be the left one, it hangs a shade lower than the other one) is what is making the noise. It's vibrating in place, creating the hollow rattle. It drives fine, but the racket is a little annoying, and makes my truck sound like a piece of crap. It's only a slight movement, but if I don't get right to this away, what is likely to happen? Is it going to vibrate apart? It looks like it's one bolt (out of three I think) that is chewed up. Is it drivable this way or is this a big problem (aside from the noise)?

    And thanks a ton for the help.

  6. #6


    You should be safe, other than the noise driving you insane.

  7. #7


    I also think that i should be a heat problems that is the reason your truck sound weirdly.Get some advice from professionals or take it to the service center

  8. #8


    Quote Originally Posted by Jhein View Post
    Also, it's a 99 Silverado, v6. I'm a tad embarrassed I somehow forgot to mention that.
    Stick it in your signature (a lot of us have it there), then you don't have to remember.

  9. #9
    Jr. Mechanic b-radical's Avatar
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    I've had a similar sound for years. It sounds like empty spray cans shaking but if very faint, and I think only occurs with the ac on. I just ignore it. Im waiting for something to actually break or fall apart until I fix it.

    2000 Silverado, 4.8L, LS
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  10. #10


    I had a similar sound on a 91 S10. It was a heat shield. I just removed it and the sound went away.

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