scorpio333

Compression test each cylinder? That's one of the first steps they did to diagnose mine. Cyl 4 was way off.

Had the truck back awhile and it's night and day. This motor is up to snuff, quiet and pulls up hill. No more 1200 RPM epilepsy in the tranny either. Very smooth and to be honest it feels more more peppy.

stein78

I finally took a video of mine. Late model 2011 (9/2011 build date) with 25,000 miles that knocks as the engine is warming up. It's quiet at cold start and it pretty much disappears when the engine is at operating temp. But this is what it sounds like idling while it's warming up. I think the cold temps we are having makes it more pronounced. As stated in numerous threads, it's loudest on the passenger side. The truck runs great and hardly uses any oil. My drive train warranty is up 10/2016...not sure what to do honestly.

5.0_FX2

My truck does the same thing. It's annoying but it doesn't have seemed to affect the way it runs. Usually worse when it's cold out.

stein78

Thanks for the response. My truck runs fine as well, smooth as butter and flies like a rocket. If this truly is 'piston slap' it may not be worth the risk of ford tearing into things. However, reading some others folks reporting oblong cylinder bores causing the issue has me a bit concerned.

icantdrive55

OK. I read thru about 50% of the responses in the thread and didn't find if there was a resolution to the OP's question, and it sounds like there's a significant number of members who might have a similar issue. I can only relate my experience with my '09 and a similar noise that happened with only 500 miles on the odo. The sound was not a tick like the injectors but a very pronounced deep knock that occurred once the engine was warmed and was pronounced between idle and about 1700-1800 RPMs. I can best describe it as very similar to a low rod knock, but higher in the engine. The dealer diagnosed the noise as a faulty VVT assembly--I don't remember if it was the solenoid, the valve, or the cam phaser--and once replaced, the engine was and still is quiet as church mouse. Just a thought….

Here's the post from my April 2009 warranty fix (FYI--This was obviously NOT the 5.0 motor, but rather the 4.6):

Here's a video of the phaser noise in a 5.4-3V (noise is heard at 3:45 in the video):

aiobst

I compression tested all the cylinders and regapped the plugs to the low end of factory spec, but didn't change anything. It went back to rattling more on 87 once the tank with octane boost was done. Going to try replacing the knock sensors and seeing if that does anything. All the data looks fine and within range when it rattles using an OBD reader. It would seen the knock sensor isn't delivering corrections or the O2 sensor isn't measuring fuel mix correctly is my best guess.

45_ACP

2012 5.0 ex-cab xlt with 40,400 milage (built in late 2011)

I too am experiencing a slight knock at idle when the engineis warm. It is loud enough for me to hear it in the truck with the windows up. Same as most of you; the knock is coming from the passenger side. I am going totake it into the local dealer and see what they have to say. Hopefully it goeswell.
I am apprehensive to have the engine replaced though. Backwhen I first bought the truck I had the lifters, or as ford called themTappets, replaced because it had a bad tapping sound and the truck only had 130miles on it.

FordService

Let me know how it goes with the dealership, 45_ACP. I'll be here to answer any questions you may have.


Brittany

ls67nova

Getting tired of this friggin knock. Posted my video below.

Brittany [MENTION=47652]FordService[/MENTION], according to the two dealers I've been through (and the second dealer's calls to Ford Tech), Ford's viewpoint is that the sound in my video is normal? And Ford's not embarrassed when I tell people "No, I don't have a diesel."?

FordService

I understand where you're coming from, ls67nova. I checked into your recent case and see that the dealer and CSM have reached a final resolution on this; please know that I'm unable to overturn that decision. Moving forward, I suggest seeking a second opinion at another local dealer; feel free to use this to get an appointment scheduled.

Brittany