Catalytic converter rattle? Heat Shield? Knock?

[ahl395]

On very light acceleration i can hear a slight rattle, only when there are cars next to me to echo the sound back to me. Only under 20mph, doesnt always happen. Very strange.

My catback has been taken off 2 or 3 times, trans and converter taken out, none of the above has changed it. It doesn't bother me much and its not loud but I still wonder what it could be.

Getting my cats removed next week so I'll report back if the tapping noise goes away after.

Sponsored

 

[MUSThavaSTANG]

Could it be bits of ceramic inside the cat have come loose and are rattling around?

 

[ryant601]

For me it was the flexpipe. Bang on the passenger cat and see if you hear a rattle from the flex pipe. Cut it out and replaced with stainless and it’s perfectly quiet again. Had rattle at 2,250 and 3,000ish rpm without fail.

 

[ahl395]

I have no more cats or flex pipe. Still have the slight rattle. Seems to happen more when its cold. :shrug:

 

[codemanstang]

On very light acceleration i can hear a slight rattle, only when there are cars next to me to echo the sound back to me. Only under 20mph, doesnt always happen. Very strange.

My catback has been taken off 2 or 3 times, trans and converter taken out, none of the above has changed it. It doesn't bother me much and its not loud but I still wonder what it could be.

Getting my cats removed next week so I'll report back if the tapping noise goes away after.

same symptom. 15 gt auto. I havent cared enough about it lol but wondered the same. maybe since my h pipe install i cant really remember

 

[ahl395]

same symptom. 15 gt auto. I havent cared enough about it lol but wondered the same. maybe since my h pipe install i cant really remember

Yep, I dont hear it much so I'm honestly not that concerned. Although I wonder if it may have something to do with my false knock. But then again when i hear it no knock is shown, so idk :shrug:

 

[Spirit Of Fire]

I have the same issue on my '15 GT auto.

 

[codemanstang]

Yep, I dont hear it much so I'm honestly not that concerned. Although I wonder if it may have something to do with my false knock. But then again when i hear it no knock is shown, so idk :shrug:

do you have any drive line vibrations as well?

 

[veeefour]

This was my problem in AT:

[ame]

 

[ahl395]

do you have any drive line vibrations as well?

Not sure. I have some NVH from the Diff bushings and cradle lockout, is that a driveline vibration? I also have some vibration and resonance coming from the driveshaft/diff area after I got trans work done, but it only happens on very light throttle at about 1200-1300rpm and since I'm usually in Sport mode I almost never see those RPMs, so I think it's a non-issue.

This was my problem in AT:

What was the cause? Heat shield?

 

[veeefour]

I am a troll

Przemyslaw Michal Jaworski
Lives in Beckenried, Switzerland
[email protected]
https://www.facebook.com/prez.jaworski

 

[Cobra Jet]

If exhaust and mechanical engine sounds are ruled out.....

Tell your Service Center (or if you're a DIYer) to get the car on a lift and check:

The emergency brake assembly where the cable is connected from the e-brake to the cables that go to the rear. This assembly can only be seen or located with the vehicle off the ground. It's located on the driver side (left), mounted to the underside of the trans tunnel and is stuffed above/along side of the exhaust.

There is a TSB or SSM on it too.

It's been found that the securing adjustment bolt to the cable becomes loose and eventually there is slack in the cable at that above referenced mount assembly. When there is slack, depending on outside temps, vehicle RPM, how hard or soft driver leaves from a stop, if or when making a turn OR a variety of other characteristics - the cable raps off of the assembly creating a metallic rattling noise at the floor pan.

It almost sounds like marbles in a tin can... and it may seem like it goes with vehicle RPM's when accelerating; it comes and goes too, which makes it harder for a tech (or yourself) to locate the source.

In some instances, the noise sounds like it is directly under the center console and other times it emninates differently making it sound like the noise is in another area under the car.

There's a few threads on here about the issue, it's as easy as just adjusting the bolt; this one below is an example w/pics:

http://www.mustang6g.com/forums/showthread.php?t=25204

Sponsored