Question Low tone Knocking/thumping!

[Glockerman]

Hi guys...I was driving my truck to run errands and while at a drive-thru window I started to hear a knocking noise on the right side of my motor. I can feel the knocking if I rest my hand on the air cleaner and when I removed the air filter, it got a little louder, it's like a vacuum thump, but pretty fast, and it's in rhythm with the idle...what can it be?????

 

[WD40]

Wow, no one have any ideals that can help him here.
Doug

 

[Glockerman]

Thank you Doug for your attention. After doing some research online, it seems like I have a bent pushrod....I'm getting a popping noise from the intake...there's a youtube video of a truck doing the exact same thing and now I'm wondering if the fix is going to be too expensive for me to fix

 

[WD40]

How many miles are on your truck, it should be covered by the 100.000 Warranty.
Good Luck.
Doug

 

[hulkster]

I would imagine you have a rocker arm failure,exhaust valve not opening/closing properly will cause a ''thump'' noise back through the intake. I have seen alot of rocker failures and in some cases bent push rod and busted lifter on the failed rocker arm

 

[Glockerman]

I have over 124000 miles...no more warranty

@hulkster.... thanks for your response as well. I think you're right, that's what I'm being told by many...i hope that's not too expensive to fix

 

[hulkster]

I guess it depends on where you take it or who you trust,as to how much it will cost, Ford has a kit available for one bank of rockers,new hdwe,etc i would suggest having the entire bank replaced rather than just the failed part. The rockers are secured using a PLASTIC clip that fails and lets the rocker arm come apart.