Ticking and check engine light
 

Hey guys, I'm hoping someone can help me diagnose these symptoms. 2008 F150 4.2L V6 with 175k miles

Just started out of the blue a few days ago. Check engine light came on with code: P2004 (intake manifold runner control stuck open - bank 1)
At the same time I started hearing a ticking noise. This noise only occurs when accelerating over 20-30mph at higher RPMs. In neutral, I don't hear anything unusual when revving it up, which makes this difficult to pinpoint where it's coming from. The frequency almost seems constant but the pitch can vary quite a bit, typically louder with higher RPMs under load.

Could the noise I hear be coming from the actuator or flaps in the upper manifold? Or maybe engine knock caused by the flaps being stuck open?

I'm more worried about the noise than I am with replacing the IMRC..

Thanks!

To my knowledge, the valves have never been adjusted either. :huh:

Solution
 

If anyone has this same issue, I took off the upper manifold and behold, it was the crappy plastic clips on the IMRC connecting arms. Replaced them and she runs fine now.

Thank you. It's nice to see a follow up post with solution to the original problem.