Rattle from Under the Hood

[sperold]

I have a really noisy rattle, generally from under the hood.

Took my metal stick and placed it on the water pump, the idler pulley brackets, the bottom of the engine near the front pulley, the AC compressor, and no sounds.
When I place it on the front converter, or the pipes associated with it, lots of noise. The other converter, not really any noise until you get to the intersection where the pipes join to go in the resonator.

When I pry on any of the pipes, the noise does not change, so the pipes are not hitting anything.

The rattle is not always there, but seems to be more apt to happen when the engine warms up.
The Y-Pipe is only a few years old (Eastern Catalytic) and does not have a lot of miles on it.

Anyone had this issue?

 

[SHOdded]

If it's marbles in a tin can, I'd suspect the converter right away. Any loss of power when driving?

 

[rubydist]

The big risk with a broken converter ceramic is that bits get sucked back into the engine on deceleration. I would get that confirmed and stop driving it until the cat is fixed to avoid a bigger problem.

 

[sperold]

No loss of power, and yes it is like a marble in a can.
No more deceleration for me, only acceleration. Really annoying sound.
Very disturbing that this happened on a Y-Pipe that is so new.

 

[SHOdded]

Hope you still have warranty coverage.

 

[sperold]

I have never collected on a warranty yet, but I have thought of contacting them to ask a few questions. But I am expecting the old "probably got damaged in shipping" line. But who knows. They were pretty helpful when I bought the unit.
When I tap on the bottom of the converter, I can't get it to make a sound, but it is pretty well braced in that location.

At first I was worried that the noise could be the crank issue, but this is not so great either.

 

[sperold]

I contacted the company for advice and they are playing possum.
Turns out it is older than I thought, I bought it in October of 2011.

I did get an explanation from a good source. Seems the converters have a honeycomb core that is wrapped in a sort of bandage, and this assembly is squeezed into the outer can of the converter. For a variety of reasons, this bandage can be reduced or the outer "can" may distort; and the honeycomb core moves around, making the racket.
The downside of this rattle is, the flakes that break off can plug up the mufflers, or as Rubydist mentioned, get back into the engine. Putting screws in from the bottom just breaks it up more.

I have my old original Y-Pipe that did not have a lot of precious metals left in it, but hey, it does not rattle. Seriously considering putting it back on, and using my rattle Y-Pipe for testing every 2 years.
The old unit used to just miss the stringent requirements in one category, but the funny thing was it used to miss the number in a different category every time.

 

[SHOdded]

Don't know how this pertains to Canada, but here's the U.S. warranty:

Federal Warranty


FEDERAL Warranty Statement

CATALYTIC CONVERTER LIMITED WARRANTY:

The manufacturer warrants that the catalysts in our converters are free from defects in material and workmanship which cause such catalysts to fail to conform with emission reduction requirements specified by the U.S. Environmental Protection Agency for a period of 50,000 miles from the date of installation of said catalytic converters. The manufacturer warrants that the external shell, including end pipes, shall be free from defects to materials and workmanship for a period of five years or 50,000 miles from the date of installation, whichever comes first. The required warranty for non-OBDII catalyst performance is 25,000 miles, but due to the high level of confidence in our products, we have increased the warranty to 50,000 miles.

This warranty is conditioned upon the converters being properly installed on the vehicle(s) for which they are designated and cataloged and the said vehicle(s) maintained in proper operating condition according to original specifications. The manufacturer will replace any such defective converter provided that it is returned to an authorized dealer along with the proof of purchase and properly completed warranty certificate. If the warranty claim relates to emission performance, proof of failure of an emission test should be provided. Manufacturer may request proof that the engine was tuned to original specifications and maintained in proper operating condition. This warranty does not cover converters that have been damaged from accidents, road debris, or the use of leaded fuels. This warranty shall give you specific legal rights. The only obligation of the manufacturer under this warranty is to supply the purchaser with a new catalytic converter assuming all warranty conditions are met. You may also have other rights, which vary from state to state.

Our catalytic converters will not in their operation, function, or malfunction result in any unsafe condition endangering the motor vehicle(s), its occupants, or other persons or property in close proximity to the vehicle(s) when properly installed on the vehicle(s) for which they were intended.

 

[LOUDSHO92]

Check the heat shield for the y-pipe. Mine broke at a tack weld and rattled a lot.

 

[Mikey]

Agreed, I pulled off all the heat shields on mine when I found that cause. The heat shielding effect was negligible anyway since they were very rusted.