I have a 2009 Flex Limited and recently when i crank it up it has a tapping sound coming from the back driver's side. It only lasts a few seconds and then goes away. Every once in a while it will do it again while going down the road. Thanks in advance for your help.

 

How to diagnose engine ticking or tapping sounds - by Keith Hamburger - Helium

 

Probably a loose bolt..

 

If you go to the rear of the vehicle and move the exhaust pipe will it make that sound you hear?

 

It sounds like it is a solenoid or something inside the vehicle that is making the noise. Moving the exhaust doesn't make it do it.