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Apparent Exhaust Rattle

M

Mike Calvert

GUEST
Have a rattle/vibration that only occurs after traveling at a high speed (60-75) for a couple of minutes. After stopping and restarting the noise occurs at seemingly the same RPM in each gear of the transmission. It only lasts for about a total of a minute which leads me to believe it's a heat/exhaust rattle problem. It never occurs unless the truck has been driven at a high speed for a few minutes. I know exhaust baffles and guards expand and contract at various temperatures? It sounds kind of like the old EGR valves or smog pumps at various times. Don't know if the AV has any such device. I'm stumped? Anyone heard a similar vibration??
 
I've heard a very slight 'buzz' that sounds like a mechanical resonance somewhere. It comes at very low engine RPM only - when starting out either forward or in reverse. Mine sounds like it comes from under the hood. Since it's very slight, and only occurs when starting from a stop, I haven't bothered to try to find it yet. Besides, these things can be tough to find.

What's interesting about yours is that it only occurs after sustained high speed driving - that'll make it even tougher to find. Good luck!
 
wrchism said:
I've heard a very slight 'buzz' that sounds like a mechanical resonance somewhere.  It comes at very low engine RPM only - when starting out either forward or in reverse.  Mine sounds like it comes from under the hood.  Since it's very slight, and only occurs when starting from a stop, I haven't bothered to try to find it yet.  Besides, these things can be tough to find.

What's interesting about yours is that it only occurs after sustained high speed driving - that'll make it even tougher to find.  Good luck!
Mines kinda hard to describe it  sounds like a rattle and a buzz. Only happens when I'm cruising around 25-35 MPH some times it will rattle and sometime it just disappear. Just happened to me a few days ago. The sounds seems to come from the front passenger side.
 
If you still have stock exhaust or even if its been changed and not the heat shield, there is a heat shield above the muffler that more than likely is the culprit, there is a TSB on this but its much easier to just crawl under there and put a slight bend in it, hope this helps.


Didit
 
I had a similar problem with my 03. If you still have the stock exhaust there is a heat sheild that is spot welded to the muffler, this sometimes breaks at the spot weld and rattles against the muffler making a strange buzz sound.
This is what happened to mine. I pulled out the mig welder and hit the spot weld again and noise was gone.

Check it out. Good Luck. 
 
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