imyy4u

all -

ok, so here are the symptoms. when the engine is cold, and i rev up to 3k rpm or so, i hear a rattle. it's more pronounced the colder the engine. it only happens between 2k-4k, and the range gets smaller and smaller and centers around 3k as the engine warms up, until the rattle goes away entirely. i checked all the exhaust stuff, and it's all tight. nothing rattles as i go over bumps, etc., so i doubt it's something loose.

my question: is it possible for the catalytic converters to rattle when cold, and then as they warm up quiet down? that is what i am guessing/hoping it is...

please tell me that is what it is and something isn't seriously wrong...i only got 18k miles on the car...and the dealer checked and "could not replicate" although i don't know how they didn't hear it...

imyy4u

bump...anyone??

jrm1900

Wish I could help but I have basically no idea what could be the source, all metal parts expand a little as they get hot, I'd check and tighten every bolt and nut I can find, specially around the exhaust manifold, try engaging the clutch several times to see if it has any effect on the rattle, turn the steering wheelto both ends etc, I am basically clueless and my 07 GT does not have such rattle, good luck to you

HellaSmooth

I had/have the same problem. Brought it to the dealership and they told me it was due to heat shields......They made it quiter but i still hear it... hope that helps...

imyy4u

THANK YOU! finally someone experiencing the same thing. glad to hear it was just heat shields...wonder why they rattle, though, and why no one can fix it?

hmmm..

UrS4

Are you on the stock exhaust. I have been noticing something very similar. A small zing of rattle at 2K and 3K when the car is cold. I have checked my axle back when it was cold and the bolts were tight and I was thinking heat shield or something loose in the cats as it sounds like it is coming from under the middle of the car. I have ran track events and some high octane unleaded fuel. I burned the cats out on my audi from doing racing events although that was after 40K and not 11K like what's on my mustang.

I won't take it to the dealership as I am sure they will blame my LM axle back for vibrating something loose. Plus this gives me motivation to buy an O/R X pipe and fix it that way.

bigpapakus

I have seen this before where the cats rattle until they get hot. Not on my mustang but on a Trans Am I had. I worked in service at Ford for a while and have seen this before.

thewarmachine

Nope. There is a TSB for this. The rattle is from the separator plate between the trans and the engine..right behind the oil pan. I just got mine taken care of at the dealer. I still hear a vibration occasionally, but it's not nearly as pronounced as it used to be.

bigpapakus

My rattle sounds like the other TSB though, mine doesn't matter rpm or cold or hot.. Just bumps..