Ashoulders1995

Hello my name is Alex and I’m new to the f150forum. I have a 2011 f150 5.0 with 64,000 miles. Late October it started the common 5.0 knock heard mainly on passenger side wheel well. Me and my wife just bought her a brand new car and I really can’t afford two car payments at the same time, my dilemma is to just keep driving my truck as long as it doesn’t get way worse or should I try to trade it for another truck, that probably has way more miles and not as nice as mine. I’m just can’t believe that my truck has this issue, I have taken the best care possible of my truck, I have always been so proud of it and how nice it is, I work hard for my money and when I was able to afford a nice truck I new I wanted a bright red f150 4x4 so that’s what I saved for. Now 6 years later I’m left with knocking 5.0 with 64,000 miles. Any advise or encouragement would be greatly appreciated and to everyone who reads this, I wish you a safe and merry Christmas.

[F2C]MaDMaXX

Either i'm misunderstanding, or you shouldn't have bought a new car if you can't afford two car payments...?

Anyway, are you saying you can mainly hear this from the wheel well and the hood is down, therefore that's where you'll hear all noises from (as the wheel wells have gaping holes through to the engine heads)

Does it change when the hood is up? can you hear the noise from another location then?

Is it really a knock? or is it more of a tick? is it present when you raise the RPM a little? and does it change speed with the engine RPM?

What oil are you using? when did you last check the level? when did you last change it?

Ashoulders1995

My truck is paid for that’s why we bought my wife a new car. I mean I can’t afford to go out and buy a new truck and have her new car payment as well. You can hear the knock even when hood open as well as on driverside and at rear of truck. I use 5w-20 Amsoil now but was using 5w-20 motorcraft blend for past 6 years. I changed oil hoping it would help with knock sound. I had oil analysis done by Blackstone and it showed normal just a little high on iron, normal is 18 mine was 22. They said oil looked good and everything seemed fine. I changed oil about two weeks ago and Amsoil seemed to help quiet the engine from its normal little ticks but knock is still there. I have no check engine lights and truck runs smooth and has lots of power. I tried running higher octane gas and made no difference. I haven’t had the dealer check out because I’m afraid I will just be paying for them to tell me it’s normal. I know it’s not normal because it never knocked in the past 6 years. If you need anymore info just ask, I appreciate the help.

Ashoulders1995

Its a little hard to tell but the knock sounds like it goes away as I rev engine, the knock definitely doesn’t get louder when engine is revved. Mainly just hear when idling, also doesn’t knock when cold in the morning only after idling awhile or after a drive.

[F2C]MaDMaXX

Hmm, so you have a 2011, it's entirely possible you have the issue with those first engines, but, i would have thought it'd have surfaced earlier than 9 years later, we'll discount it for now.

The iron count isn't good news, but you'll not get anything from AMSoil that you won't get from the other major brands, oil choice is a personal thing, but personally i wouldn't bother with that expense. I would, however, recommend going to a 5w30 instead, maybe even consider Rotella Gas Truck, has a different additive package more suited to large hot engines of this type.

Are you using a Motorcraft filter? if not, i'd recommend switching whatever is on there to a Motorcraft, they're cheap and work well for this instance with a reliable drainback valve, you can change that "live" and only lose the amount of oil that the filter holds (no need to drop oil to change the filter if the engine is off)

Can you get a recording of the knock?
You're describing pretty much what i had with mine a few months ago, and whilst very noticeable, to me at least, it wasn't really a knock, it was more of a heavy tick - it didn't make the noise cold, only after up to temperature and only when idling.
I fixed it by discovering my injectors were likely not feeling well, i ran a double strength dose of Techron concentrated fuel system cleaner through the tank and the tick stopped after several drive sessions. I ran two of these (at the same time) through my 36 gallon tank.
https://smile.amazon.com/Techron-Con...7576419V&psc=1

Brian2012f150

"Are you using a Motorcraft filter? if not, i'd recommend switching whatever is on there to a Motorcraft, they're cheap and work well for this instance with a reliable drainback valve, you can change that "live" and only lose the amount of oil that the filter holds (no need to drop oil to change the filter if the engine is off)"
This worked for me. Solid advise.

Ashoulders1995

Yes I have always used the motorcraft oil filters, I have AMSoil P.I. Fuel system cleaner in my tank right now along with amsoil upper cylinder lubricant. I haven’t tried 5w-30 yet but was going to try my next oil change.

Ashoulders1995

I work tomorrow, so when I get off I will get a recording of my truck idling after I have driven it home. Thanks for the input i really do appreciate it, I will get some of the fuel cleaner you recommended as well. I have lost a lot of sleep lately due to this knock and really want to figure it out so I can enjoy my truck again.

[F2C]MaDMaXX

I'm 99% certain the cleaner you're currently running doesn't contain any PEA, which is what you need, and in decent quantities for a proper one-off clean, that's why i recommended that specific one to use in this case.
Also concerned you fell down the AMSoil rabbit hole upper cylinder lube, interesting.... yeah, don't bother

Ashoulders1995

Yeah I’m definitely in the Amsoil rabbit villa, lol! I bought 12 bottles of the upper cylinder lubricant because I heard you should use a bottle in every tank to get the peak amount of protection. I know it’s dumb but I guess I thought if I use this really great stuff maybe all my truck problems will go away. I’m just trying to get my truck back to healthy sounding again. I ordered two bottles of what you recommended. What grade gas should I mix with?