2010 Mustang Magnaflow Catted X Exhaust Rattle

[daylight]

i just put a magnaflow catted x in my car, and everything is snug and all but when i cold-start the car there is an intense rattle for about 30 seconds or so until the idle comes down. any ideas what it could be ? maybe the heat shield ?

[mrnoodley]

It might be the inspection plate. VERY common. To fix it right you have to pull the trans. I have to do mine, and just need to find the time. I've heard that sometimes pulling the 2 bottom inspection plate bolts and reinstalling them with a thin rubber washer can fix the rattle.

Just give me a call, PM, email or something. You can bring the car by the shop and we can toss it on the lift and check it out. You havent been here yet, but I'm just south of 70 on Rt.9.

[daylight]

yeah that could be it, it definitely sounds like metal on metal and a "tinny" type of a rattle

[Hotshot]

Honestly if you had it only after you installed the X pipe then i'd suspect that as the culprit. Check the hangers and see if they are rubbing against something metal. I've got a rattle right now myself, i just have to readjust and align it properly and it will go away. i've self inflicted a rattle about 4 times lol

[mrnoodley]

Quite likely. I was thinking about it and the few times I've seen the inspection plate rattle, it comes in at 2-3k until the car warms up.

Sounds like exhaust to me too. Easy to tell once its in the air.

[GT800]

make sure the back of the exhaust didnt drop because its really tight in the back bt the panhard brace

[daylight]

Hopefully I'll get it on a lift in the next couple days with christmas coming and all, the weird part about it is it's there only in initial cold start, at about 1100prm and after about 15 seconds it's gone. Also if I'm stopped or driving and I rev it at 1100rpm I can't duplicate the sound, thanks for the input guys I'll hope to get it in the air soon

[gtncpa]

Mine rattles on start up. Has done it since its new.

[daylight]

Just looked under the car the one clamp is leaking, could that be the suspect ?

[GT800]

yup completely possible