Hey guys, you helped me out a bunch a few weeks ago and am hoping for the same...

A few days ago I noticed, when I take off from a red light or stop sign, my truck sounds like there is tin can with a screw inside of it rattling around (from what sounds like the back end). It's very odd...it doesn't usually happen once i'm moving along, although, sometimes I can hear it. I jacked it up and checked around for anything that might be loose or just hanging around (as I thought it might be the exhaust coming loose) but nothing. I think I've narrowed it down to it happening when the weight of the vehicle shifts back or forward, although, I don't usually hear it when breaking, but sometimes I do...

I know this isn't very speicifc, but maybe someone else has head of this, any feedback would be great!!

 

Check out your exhaust system with either a rubber mallot or a gloved fist, start around the cat and go back to the muffler. Some times the converter material will break off inside the cat and make a sound. It could also be the baffle in the muffler has broken loose and is rattling...depending on if the muffler is still the factory original or not.

I had a Dynomax muffler go bad after a year installed. According to the mechanic I checked with the internal baffle had broken loose and was allowing more noise out the muffler under deceleration (raspy noise)...

This could be your rattle noise.

 

OK...so I thought it was the cat because at higher RPM's the truck feels like it's lost power or something is holding it back...but, here is the weird thing, if the truck is in neutral, and I give it some gas, I don't hear the 'tin can' thing...but if I have the truck in 'drive' it makes the ticking/tin can sound as I start to take off...

BTW...the SES light has not come up either. If it were a cat issue, wouldn't a code be thrown?

thoughts?

 

Some people hear have had rattles in the exhaust system and they say that when they check the computer settings with a scan tool they find that the computer interprets the rattles as engine knock and it changes the ignition timing to remove the knock, which means that it will feel like you are loosing power.

It could be possible that a motor mount is loose and when you put it into gear a part of the exhaust is hitting something. So check for anything close to the exhaust system that when you put it into gear would cause a rattle noise....if you are careful with a 4x4 someone could lay length ways along the under side and check or if you go to an oil change place with a pit or drive on lift then you could check it that way....

As far as the computer setting code, it will only set a code if the sensors measure a significant difference from the front of the cat to the rear, if flow is still fairly normal then no code would be set except for a possible pending code.

 

I can't find anything that could be hitting the exhaust and this seems to be getting worse...it's very odd. I might have to break down and take it to someone to check it out. Or, maybe next time I get in the vehicle, the problem will be gone!!!