UH Oh .... So I started to hear a sound in the lower end uh oh... It happens when the vehicle has been driven awhile and warmed up then stopped for awhile. While the engine is still a tad warm and started back up I hear the sound some times. If it is idling you hear it but when revving a bit it seemingly goes away. No loss of performance to speak of and otherwise runs fine.

I took a recording of it an attaching it to the post here. You can hear the motor in the back ground and the noise in the foreground. You may listen a few times to sync those sounds in your head.

I am holding the phone on drivers side under the oil pan.

Any guesses?

 

The sound was from the transmission cooling lines (metal ones) chattering between the mounting brackets. They were tightened down and chatter no more

 

So the sound came back. Was one hell of a coincidence to have it go away then return twice as loud.


Anyway for those who might run into the problem later it was the flex plate on my automatic transmission. It is easy to see the flex plate just remove dust cover on bell housing and look in with flash light.


Here is what the flex plate looked like after replacing.