rattling under hood....

[Dustin07]

ok....

 

did the pound test on the cat. converters. on the passenger side we get almost no noise. on the drivers side i get a rattling that comes from further up towards the engine, but it doesn't sound like it's actually from the exhaust at all. took it to two muffler shops, and neither one thought it was the converter or exhaust related.

 

1st shop thought it was something in the flywheel area that could have come loose. offered to check for 1 hours worth of labor... this was after he had it lifted and took it for a drive. What could he possibly check in the flywheel area that would only take an hour????

 

2nd shop found a small crack forming on a heatshield on the drivers side of the engine. i'm thinking about replacing that heatshield to see if it's causing the noise, but i honestly doubt that is it. it's a loud knocking noise that only comes when the engine is under pressure. so either when it's cold, or in reverse or in drive, but hardly ever in park or neutral, if it's warmed up. under accelleration it will knock, but once i hit a cruising speed it will shut up, unless i have to work it (typically over 1500rpms) to keep that speed (like up hill).

 

there is no felt difference in the trucks driveability or power. and it sounds like something loose bounces back and forth or rattles. i guess it could be the heatshield, but from the look of the crack, it doesn't even look like it's coming apart at all, just a little crack...

 

what do y'all think?

[Dustin07]

ok, got a lot of lookers but no comments... have any of you at least had a simliar sound?

 

I've heard that the o2 sensors could be out of whack, but everything seems fine there....

[quackmaster]

ok, got a lot of lookers but no comments... have any of you at least had a simliar sound?

 

I've heard that the o2 sensors could be out of whack, but everything seems fine there....

 

<{POST_SNAPBACK}>

 

 

 

 

may be fan clutch bearing. Mine made a noise under the hood and that is what they are replacing today.