Knocking on rear driver's side

[acetactical]

Before the raping and pillaging, I swear I searched and came up empty handed...

2005 Ford Explorer XLT V6 4X4-Pretty stock

I have a knocking sound coming from the rear driver's side. The knocking starts right at startup and ends when I kill it. It keeps the same tempo regardless of my speed or if I'm stopped. I'm ripping off the interior at the wheelwell now to find the damn noise. Any input would be appreciated. Thanks guys!

 

[acetactical]

Quick update, 2 important details (or maybe not):

1) The knocking starts when the vehicle is turned on, even without the engine running. Not that I thought the engine was back there or anything. Just thought it might be an important detail.

2) I'm not intelligent enough to figure out how to remove the interior panels surrounding the rear wheelwell The sound is DEFINITELY coming from in there tho!

 

[KPPCExplorer]

Do you have rear air? Almost sounds like someone is tapping on a body panel?

If so, it's your blend door actuator. It should be in the panel on the driver side of the 3rd row. If you adjust the rear air temperature, it should either get louder or quieter. I had the same problem, a new module is about $50 and the repair is easy, I hear dealers asking quite a bit to repair, so if you have the confidence to do it, than go for it.

 

[mesmorales49]

Knocking noise rear driver's side '07 Explorer

Ok, that sound is scary if you know nothing about car malfunctions/causes. I can't afford to be taken$$ by the dealership, so I just want to know if this noise which comes on every 10 seconds is liable to cause an accident. Give me a break, I just lost my husband who never taught me about such things and the latest thing that sounds like it's breaking is my car.