2020 5.7 Engine Knock

[Volunteer1589]

I have a 2020 Laramie 1500 4x4 with the 5.7. Truck started a bad engine knock on the way home from work. It’s a 17 mile trip one way and did not start until I was almost home.
Crawled under the truck and had my wife rev a few times so I know it’s not an exhaust manifold. It seems to be louder at start up even though engine is already warm.
Truck has 31.5k miles and run 87 octane. No engine issues prior to this. Any idea what could be the cause? Of course I am thinking the worst. Taking it to the dealer tomorrow. I tried to post a video but can’t get it to work.

 

[CNC99]

Upload the video to YouTube and post the link.

 

[djevox]

May be a good idea to tow it just to be sure you don’t blow a piston through the block on the way to the dealer. I was typing this when CNC99 made their response, and I agree with them that a vid with good sound would help.

 

[Volunteer1589]

 

[Volunteer1589]

Upload the video to YouTube and post the link.

Video uploaded

 

[Volunteer1589]

May be a good idea to tow it just to be sure you don’t blow a piston through the block on the way to the dealer. I was typing this when CNC99 made their response, and I agree with them that a vid with good sound would help.

Video uploaded. Towing it was my first thought as well.

 

[Jeffjad]

Yikes! Definitely sounds like piston slap. Hope they diagnose it quickly and get you fixed up.

 

[Darksteel165]

RIP

 

[djevox]

It is a video and could be a cracked exhaust manifold, but chances are it’s the engine knocking.

 

[Darksteel165]

View attachment 154085
It is a video and could be a cracked exhaust manifold, but chances are it’s the engine knocking.

That sounds nothing like a cracked manifold imo.
Maybe he has a cracked manifold, and a dying engine too!

Also use 89 after they replace\fix your engine.

 

[Volunteer1589]

View attachment 154085
It is a video and could be a cracked exhaust manifold, but chances are it’s the engine knocking.

I see trading this in my future but I did get a good laugh from your post. First Ram. First new truck I’ve bought off the lot. Absolutely hate this happened.

 

[Volunteer1589]

That sounds nothing like a cracked manifold imo.
Maybe he has a cracked manifold, and a dying engine too!

Also use 89 after they replace\fix your engine.

Will keep the 89 in mind thank you. I used to run 89 or 91 but haven’t in 20k miles after gas went through the roof.

 

[djevox]

Will keep the 89 in mind thank you. I used to run 89 or 91 but haven’t in 20k miles after gas went through the roof.

Assuming your engine is stock*, the ecu can account for low octane/bad fuel by retarding timing when knock is detected and knock counts crosses a threshhold. That was a little simplified, but I’d lean towards a internal part part failure (due to defect or improper/no oil) before I’d point the finger at 87 octane.
*The reason I mention stock is if tuned improperly, the ability to auto adjust the timing as a response may be altered with bad consequences.

 

[Volunteer1589]

Assuming your engine is stock*, the ecu can account for low octane/bad fuel by retarding timing when knock is detected and knock counts crosses a threshhold. That was a little simplified, but I’d lean towards a internal part part failure (due to defect or improper/no oil) before I’d point the finger at 87 octane.
*The reason I mention stock is if tuned improperly, the ability to auto adjust the timing as a response may be altered with bad consequences.

I’m leaning towards internal part failure as well. Truck is stock besides small lift, tires, and magnaflow muffler. Oil was just changed less than 1000 miles ago.

 

[Volunteer1589]

Found a dealer 45 minutes away that can look at it next week. Every other dealer around here will not look at it until the end of the month. The nightmare continues.

 

[CNC99]

Definitely not just the typical exhaust leak. Definitely some sort of part failure, I hope there is a new engine in your future! Best of luck.

 

[User_119824]

Owner's manual states 87 is fine for this engine and 89 is only recommended for peak performance.

This issue sounds like a factory defect, not something caused by using the recommended fuel grade.

Hope they get you fixed up. Went through 3 engines, 2 transmissions, and a partridge in a pear tree when I bought my brand new 2018 F150. Hope you have better luck with the Ram and can understand if you want to trade out. Keep us posted please.

 

[Darksteel165]

Assuming your engine is stock*, the ecu can account for low octane/bad fuel by retarding timing when knock is detected and knock counts crosses a threshhold. That was a little simplified, but I’d lean towards a internal part part failure (due to defect or improper/no oil) before I’d point the finger at 87 octane.
*The reason I mention stock is if tuned improperly, the ability to auto adjust the timing as a response may be altered with bad consequences.

No one is pointing a finger at 87 vs 89.
I simply said to use 89 in the replacement engine.
These engines like better quality\octane fuel.

Also use 89 after they replace\fix your engine.

 

[Volunteer1589]

Truck has been towed to dealer. They won’t be able to look at it until next week so will post updates once I know something.
Service advisor did ask about my recent oil change. Had it done at Firestone as I did not want to wait a month for an appointment at the dealer. Service advisor said if Firestone used the wrong oil then my warranty will not be honored. Really hoping that’s not what happened but it sounds like my luck.

 

[Jeffjad]

Truck has been towed to dealer. They won’t be able to look at it until next week so will post updates once I know something.
Service advisor did ask about my recent oil change. Had it done at Firestone as I did not want to wait a month for an appointment at the dealer. Service advisor said if Firestone used the wrong oil then my warranty will not be honored. Really hoping that’s not what happened but it sounds like my luck.

Wow, sounds like the dealership is already looking for an out. Unreal!