Vibration I just can't pin down

[Hartman]

I have this weird vibration that I can't figure out. The best way to describe it is a "metal to metal" vibration that pulsates. It only happens when I'm in gear, and when my foot is on the brake. I first thought I had a front brake pad that was shaking but since it only happens with the foot on the brake, wouldn't that secure the pads against the rotor, thus holding them firmly? I replaced the rotors 1k miles ago, so it can't be that. I'm thinking maybe it's an exhaust issue, but there doesn't look to be any holes or anything.

Can someone help me figure this thing out?

 

[Alec]

You said you looked at the exhaust, did you make sure it's not hitting anything?

 

[Hartman]

I have checked it over and it seemed sturdy. I will look again this weekend, but it seems like it's coming from the front end of the truck. It's a pulsating vibration though, meaning there are 1 second intervals in between the vibrations. I don't see how it can be the exhaust though, because it only happens when the truck is in gear.

 

[Alec]

My exhaust vibration only happens in first gear when I'm going 0-3 mph, and it only happens about once a week. I know for a fact it's the exhaust though.

Anyway, I'm still thinking....

 

[JDraper]

Have you checked the heat shields on the cat converters?? They are known to do that after a while. It may only be happening in gear because the rpm's are lower in gear, and the lower rpm's might be generating a resonant frequency in whatever is causing the noise.

 

[Mike 97]

Hartman - I have the same problem with my truck. I looked and looked - tapped the exhaust with a rubber mallet and found it! I had to drop my converter to be sure of myself. It is where the converter bolts to the y-pipe - in the spot where the two manifold pipes come together. Looks like we have an excuse to get headers

 

[Hartman]

Mike, it's interesting you would say that. I had my plastic fenderwell out the other day on the passenger side. I noticed some whiteish green mineral deposits all over the exhaust pipe just where it connects with the header. Maybe this is the source of the vibration?

 

[wlkingdude]

Hi Hartman,

I have the same problem. Did you ever find the source of the vibration? Was it the exhuast?

 

[Redrig]

this may sound dumb but i had the same problem it sounded exactly like a loose heat shield. but when i got a new tranny it stopped. does a tranny ever make that sound? or maybe it was part of the exhaust that he removed to do the tranny and tightened it when reinstalling it.