2020 bighorn with an engine knock

[TurdofaRAM]

I have a 20 Bighorn 5.7 that ive had nothing but issues with. I first heard this knock with about 1.5k miles on it. Its a low level knock/clacking sound every time i accelerate. Ive taken it to the dealer 8 times, they first saw i had a misfire and replaced 2 plugs and a coil pack. That didn't fix the knock. Called FCA for help, absolutely useless. All they do is contact the dealer for you.... what's the point in that???? They lost my case for 3 weeks and then tell me they can do nothing for me. They tried to say it's a normal sound these trucks make, so twice now I have called them on their bs and made them drive me in their other vehicle to try and duplicate the knock... man those trucks sound perfect. Not a single knock. Chrysler then asked me to take it to another dealer for a 2nd opinion. Right off the rip they again tried to say it is a normal sound, so again we took out their truck... again it didn't make a knock. Im a ford guy. I traded in my 16 F250 and feel like i made a terrible decision. FCA is useless, don't even waste your breath calling them... the dealers both say it's normal for a brand new truck to have an engine knock.... (bs) i spoke with a rep from FCA who said "hopefully it fails, that way we can figure out what is wrong with it " not their family thats going to be stuck waiting for a tow truck for hours, or God forbid something worse. You guys have any ideas? Should I just lawyer up? Is an engine knock even something you can lemon law in FL??? All they want to do is sell me a new truck... thwy offered me 5% off a new one. They have had the truck now a total of 15 complete days. Im also getting about 10.6 mpg. Tried all octanes of fuel.... let me know if you have any experience with this or maybe a direct i can go. Thx

 

[Drewster]

True engine knock varies with RPM - this sounds more like a single thunk as you accelerate? If so, I wouldn't call it engine knock.
If it's just a thunk as you accelerate, I would have someone rev the engine at idle while you watch the engine bay. If it thunks as the engine rotates, you should be able to find whatever is loose and thunking. If it only happens in gear, it's likely drive-line related. You may have put the techs down the wrong path telling them it's "engine knock"

If it *is* engine knock that varies with RPM, are you running cheap gas? If so, I would run a *full* tank of premium (91-93 oct) Top Tier gas. The manual actually states directly that light engine knock with lower octanes is normal.