Noisy acceleration

[shop hermit]

Noticed something different recently. When I'm accelerating I notice a noise that sounds like something vibrating in sympathy or resonating with the engine speed. What it really sounds like is a loose baffle in the muffler or the heat shield around the muffler. I don't have a tach, but I would guess it happens at around 2500 rpm. I checked and couldn't find anything loose in that area. Don't notice it on light acceleration, just when I'm pushing it a little. Seems to be at the beginning of the torque curve, then disappears as the speed catches up with the acceleration demand. Probably just a coincidence, but I first noticed it after removing the engine air filter and cleaning it by blowing it backward with compressed air. Anyone else notice anything like this???

[SubSlr88]

Yep - mine has done it since early ownership . . . just something vibrating, no doubt - I figured exhaust system. Maybe yours just needed to have it's ear blown into to show this up . . . 8=)

[a2jack]

Yep, here too. Just another "quirk" on a very quirky car. (BD Jan 08, 27k on ode.) A2Jack.

[HGB]

Peel back the engine carpeting and make sure the center screw seals the engine cover down all the way. Sometimes the screw may not have been tightened enough and may loosen again.

[shop hermit]

Nope. It's not the engine cover thing. That worthless little piece of jumk gave it up about the fourth time I opened the cover. I modified the threaded clip to take a quarter-twenty cap screw and now I can screw it down tight. Anybody ask the dealer about it ?

[SuperGeek]

I have something similar, it's been that way since day one -- with a cold engine and transmission (< 2 mins since start), merging onto a road with traffic at 40mph, I hear what sounds like a vibration in the back. When it warms up it's present less often, and I figure it's just the engine vibrating with heavier than average load. Maybe the muffler doesn't flow the same when cold? Maybe the cylinders don't combust as smoothly when cold, causing more vibration? Just guessing here.

[JohnnyM]

Yep here's another one. The sound reminds me of another vehicle I had and the noise turned out to be a heat shield on the exhaust system.

[shop hermit]

Well, sounds like I'm not the only one at least. I agree, it really sounds like it might be the heat shield. And, yes, I do notice it more when it's cold. Think I'll jack it up tomorrow and investigate that area a little more thoroughly.

[shop hermit]

results of investigation. Found three things that were possible culprits. First is a thin aluminum cover around the pivot arms from the center to each rear wheel assembly (apparent function is to shield rubber bushings from muffler heat) Cut stiff foam rubber plugs and inserted between arm and covers...about 8 in all. Next , look at the black plastic "bumper"on the rear. It's pretty floppy and looks as if they might have intended to put a reinforcement strip on the bottom(there are a row of tabs with holes in them) I cut a strip oak about an inch wide by a quarter inch thick as long as the bumper. Drilled holes to match the tabs and mounted it to the tabs inside the bumper. Couldn't find anything loose around the muffler or shield, but did notice that the engine air canister made a small clicking sound if I rocked it back and forth, so I wedged a piece of stiff styrofoam between it and the deck cover. Took it out for a test drive and MY NOISE IS GONE. Don't know which one of the three did it, but something worked!

[mvaldes]

Congratulations on a successful (and) resourceful resolution of your problem.