I'm trying to figure out where a rattling noise is coming from.

1992 CHEVROLET SILVERADO

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I drive a 92 Chevy pickup 2500 with a 5.7 It has begun to produce a rattling noise under the truck towards the front. It only occurs during acceleration in gear and after the engine has warmed up.When it's idling in park, it sounds fine. It's driving me nuts not knowing what it could be. I've checked, rechecked and checked underneath the truck and just cannot figure it out. Thank you so much for your time.

Sep 16, 2012 at 3:09 PM

ASEMASTER6371

✓Experienced Mechanic
52,796 POSTS

see if there are any loose particles inside the cat converter. hit it with a rubber mallett to see if anything is rattling around.

Roy

Sep 16, 2012 at 3:18 PM

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Thank you for the reply. That was one of the things I had checked but that wasn't it. I did some further checking and can hear it now in the engine compartment. I used a piece of hose and can only hear it on the right(passenger) side. I found a couple of slightly loose exhaust manifold bolts. I haven't checked to see if that was it yet though. I just don't understand why only when accelerating in gear and only after it warms up.

Sep 16, 2012 at 5:42 PM

ASEMASTER6371

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52,796 POSTS

exhaust leaks go away when warm, not getting worse. does it sound like a valve tap??

Roy

Sep 16, 2012 at 5:48 PM

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To be honest, I'm not sure. I'm just kind of a shade tree mechanic. When it comes to internal engine issues, I don't have a clue. I was hoping this whole thing would be something simple, but I guess it's not going to be. You don't think it could be caused by using a different oil weight do you? It's supposed to take 5w30 but I used 10w30

Sep 16, 2012 at 6:27 PM

ASEMASTER6371