Metallic rattle when accelerating under load

[Hank3]

I had been hearing a metallic rattle from 2nd-5th gear under load while accelerating between 1,500-2,500 RPMs. I took the opportunity to troubleshoot it yesterday afternoon. With a ratchet in hand (10mm socket), I went underneath the car and started tapping all manner of things while paying special attention to all of the exhaust heat shields. Nothing rattled from my tapping. I then used the ratchet to go over all of the screws/bolts that fasten the various heat shields. There was one screw in particular on the J-pipe that fastened a corkscrew clip of sorts. The corkscrew clip was keeping the wire to a heat probe (I think) from making contact with the heat shield. The screw wasn't that loose. It needed about a 1/4 to 1/2 turn to make it snug and tight. That was the ONLY one I could find after spending about 10 mins underneath. I was cautiously excited that that was the culprit.

Went for a drive and now I'm back to metallic rattle-free driving. As far as other rattles with the car...well there's always another day

 

[Maroon]

I wish they were all that easy. This is the worst rattle trap of a car I've ever driven. And I own a Jeep!

 

[kamesama980]

I wish they were all that easy. This is the worst rattle trap of a car I've ever driven. And I own a Jeep!

Really? My wife's is completely noise free at 95k except a slight wheel bearing hum her dad says has been there since they got it and a dragging strut mount that isn't OE.

You think a Jeeps bad, try a mid-90s GM. The whole 4 ft long center console has 2 tabs in front and 2 screws in back holding it down.

 

[BlueBomber]

I am having this same problem and it's been making me crazy. Thanks for the post now I have something to home in on.

 

[Maroon]

Really? My wife's is completely noise free at 95k except a slight wheel bearing hum her dad says has been there since they got it and a dragging strut mount that isn't OE.

You think a Jeeps bad, try a mid-90s GM. The whole 4 ft long center console has 2 tabs in front and 2 screws in back holding it down.

95k isn't much. Just wait. Suspension and steering are particularly bad.

 

[BlueBomber]

So I had my car up on stands for an oil change today, and while doing that I examined the bolts for all the heat shields. The ones that hold those corkscrew clips were really tight, I was able to tighten them only a tiny bit more. I noticed the bolts holding the rear heat shield on weren't very snug, so I tightened those as well.

I went for a quick test drive after, and purposely tried to make the sound happen again but I couldn't hear it. I wonder though if it only starts to happen after you've been driving for a while and the car really heats up?

Anyway I'm hopeful, but doubtful, that the noise is gone.

 

[Hank3]

Hope it's gone for good. Just slight tightening will do the trick with our cars. I still have all OEM engine mounts so the vibrations are pretty noticeable...can cause bolts and shields to chatter.

 

[BlueBomber]

Well I just went for a short drive and I can still hear it.

My car still has the factory original engine mounts. It only has 120,000 KM on it though, which isn't very much. I've been observing this for a while, and as far as I can tell, the rattle (sounds more like a metallic "flutter" or "flapping" sound) ONLY happens when the transmission is under heavier-than-normal load, around 1500 to 2500 RPMS. (for example if I'm gunning it up a hill.) I have to wonder if the clutch is slipping or skipping? I don't really notice a loss of acceleration or power though.

I hear this sound on LOTS of other P5s around the city.... someone must know what causes this?

I'm going to lift the car again next weekend and just start tightening every bolt I can find.

 

[sleepwalker]

I've had a similar sound for a little while now. It might not be the same thing as yours but it sounds like it when I read it in text, lol. It sounds a lot like a loose and rattling throwout bearing to me, especially since it's sort-of clutch dependent. Think that might be a possibility?

 

[Veretos]

My car makes the noise your describing at the same conditions (under load, usually up a hill). Ive made sure every damn bolt on my exhaust is tight and it still does it, ive been doing some reading and i'm thinking it may be the VTCS in the intake manifold. They are little vanes that create turbulence in each runener to 'mix up' fuel droplets but the vanes can become loose and rattle under certain throttle positions. You should be able to find the same post i did on the forums by looking up VTCS removal