I have a 09 f150 5.4 76,000 miles, replaced with oem ford parts , the cam phasers, the variable timing seloniods, new timing chain and tensioners, and installed a melling high volume oil pump, truck idles smooth runs great, no fault codes, even contacted from youtube fordtechmakuloco, he said try using 10-40 oil, still have the chattering noise when climbing a hill , .....any suggestions ?

 

Spark Knock?

 

Does it go away if you use premium gas? If it's a 4wd, what about in 4wd?

 

I think your on to something there, it doesn`t chatter when in 4wd, so I`m guessing it might be vacuum related ?

 

Yep, it's your IWE's grinding. Read the following thread from our Articles and How-To's forum:

https://www.f150online.com/forums/ar...then-some.html

 

Great info !...thank you

 

so the noise that I hear , the best way to describe it is that of a heat shield on your exhaust coming loose and vibrating and chattering, my 4wd will engage, so I take it that I`m losing vacuum that keeps in 2wd and the sound I hear is it trying to engage ?

 

That is probably the issue if the noise goes away in 4wd. The linked thread will help you troubleshoot it.