A year ago I had some odd noises that sounds like a rattle only when the truck is stopped and in drive. The noise also only gets noticed when it's cold out (< 50F) from what I can tell.

Back in the spring of this year I had a new transmission put in and in doing so found that the snout of the torque converter had broken about 50% off. The torque converter was rebuilt and put back in as well. So the noise stopped but the weather also warmed up once this install was finished.

Fast forward to this week, and the weather gets cool again and the noise is back again with a similar circumstance of only happening while in drive, with the truck stopped. Barely let off the brake to roll just a hair forward and the noise stops until the trucks comes to a rest again. Start driving normal and the noise is gone as well. Also, while stopped and in drive if the noise can be heard (it comes and goes sometimes) I can turn my steering wheel slightly and the noise will get louder momentarily.

From outside the truck on the drivers side it sounds like it's coming from the bell housing area under the truck. On the passenger side it sounds like it's coming from the rear end. Maybe the noise is travelling down the exhaust or the driveline...? I can put the truck in drive and apply the parking brake and get out to listen to the noise and feel around and no abnormal vibrations can be felt from the transmission.

I'm beginning to wonder if it might be related to the exhaust/cats and not the drive line and the subtle changes made in steering or moving etc. might make the noise start or change due to frequency changes with the vibration. It's all a guess at this point. Just curious if anyone else has experienced something similar.


The truck is an AWD Sierra Denali with ARH headers with cats and a Corsa catback. Other than the exhaust and the rebuilt drivetrain and -2" struts and -3" rear shackles it is stock. Going to see if I can get the trans shop to listen to the noise at lunch today but I run the risk of it not showing it's head once I approach a shop just because that's how these little PITA noises tend to be in my experience.

 

Might check the torque converter bolts, I've seen them work loose and make a noise under those conditions.

 

Trans shop put it on the lift real quick and found what they thought was the problem. The headers were hitting the frame. I guess the cooler weather was just enough for the metals to move around some to make the contact after the truck ran long enough for the headers to heat up and move themselves.

They bent it just a little out of the way and so far no more issues. Hopefully it's as simple as that and I'll look into the area closer during the next oil change and see if a spacer can be put in somewhere to give some more room.


Another thank you to CircleD for taking care of it with no notice on a busy holiday week.

 

My truck is doing something really similar, but I have no headers just a Corsa catback. Is it a Corsa DB system or regular Corsa catback?