Warm up piston slap?

[JLaw297]

My 2019 Ram with 51k miles now has been making this sound at idle, but only while it’s warming up. Truck has very low idle time (127 idle hours). Sound is completely gone once warmed up. First noticed it around 30k mile mark. Truck runs strong and smooth, taken on several road trips and gets great mileage. Doesn’t miss a beat.

I’m leaning toward piston slap since as things warm up and expand the sound goes away. I feel like a failed lifter you would always hear. If it was a roller failure I don’t think it would have made it 20k miles now. You can also have a lifter that’s weak hydraulically, but I would think it would pump up after a quick drive to get good oil pressure and not routinely take until full warm up. Thoughts?

 

[Jake103]

Have you checked your exhaust manifold/header gaskets or bolts? Very common on the 5.7 louder tick when cold goes away when warm. When I worked on cars most of the 5.7's we were replacing the exhaust manifold gaskets.

 

[Jeffjad]

My 2019 Ram with 51k miles now has been making this sound at idle, but only while it’s warming up. Truck has very low idle time (127 idle hours). Sound is completely gone once warmed up. First noticed it around 30k mile mark. Truck runs strong and smooth, taken on several road trips and gets great mileage. Doesn’t miss a beat.

I’m leaning toward piston slap since as things warm up and expand the sound goes away. I feel like a failed lifter you would always hear. If it was a roller failure I don’t think it would have made it 20k miles now. You can also have a lifter that’s weak hydraulically, but I would think it would pump up after a quick drive to get good oil pressure and not routinely take until full warm up. Thoughts?

Definitely sounds like exhaust manifold leak. I would start there. Had both of mine crack before 30k miles.

 

[JLaw297]

The thing is, it doesn’t tick right from start up. Once it idles down to normal idle rpm is when you start hearing the knock. The cracked manifolds I’ve heard you hear instantly regardless of rpm and stays that way till warm. My knock disappears with any rpm increase over idle.

 

[jmiller8605]

Do the newer 5.7's suffer from collapsed lifters like some of the older ones? Usually wouldn't be that early on in it's life. I had to do a top end rebuild on a Durango with 180k miles due to collapsed lifter. Kinda sounds like it could be some valve slap until the hydraulic lifter gets pumped up.

I would lean towards the exhaust manifold as well, or at least verify that's in good shape, but if it's not that I would say you got a dieing lifter that will eventually grind away your cam.

 

[Jeffjad]

The thing is, it doesn’t tick right from start up. Once it idles down to normal idle rpm is when you start hearing the knock. The cracked manifolds I’ve heard you hear instantly regardless of rpm and stays that way till warm. My knock disappears with any rpm increase over idle.

Either way it will be covered under the 60k powertrain warranty so take it into the dealer and let them figure it out.

 

[User_72751]

That's an exhaust leak. At an elevated idle, such as a cold start, the exhaust creates more of a scavenging affect and you don't hear the leak. Once the engine idles down the exhaust pulses change and you start hearing the manifold leaks. Once it warms up the manifolds expand and the leak seals.

 

[Vilas15]

The thing is, it doesn’t tick right from start up. Once it idles down to normal idle rpm is when you start hearing the knock. The cracked manifolds I’ve heard you hear instantly regardless of rpm and stays that way till warm. My knock disappears with any rpm increase over idle.

Mine does the same. If i start it up and immediately go into gear the RPMs drop from 1200 to like 700 and you can really hear it. But if i let it warm up and let rpms come down to normal idle on their own then its not nearly as noticeable.

 

[JLaw297]

Hopefully that’s the case, but doesn’t sound like an exhaust leak at all to me.

Here’s a better video -

 

[theblet]

Hopefully that’s the case, but doesn’t sound like an exhaust leak at all to me.

Here’s a better video -

That does kinda of sound like slap. Could be an accessory as well on the serpentine belt

 

[BlackNight]

Hopefully that’s the case, but doesn’t sound like an exhaust leak at all to me.

Here’s a better video -

I'm glad you posted this video. My 22' has 800 miles on it and I hear the same noise. Only at idle. Hopefully it rears its ugly head before the warranty is out.

 

[66Fuelie]

I would be shocked if its piston slap. 5.7 Hemi's come from the factory with hyperutetic pistons, piston to wall clearance is .0015-.0002. Not really like the old days with forged pistons slapping until warm up.
Tom

 

[SD Rebel]

Sounds like broken exhaust manifold bolts, they sound like loud ticking when cold and almost go away to very faint ticking when warmed up. I would check there first before you look at anything else, but if under the factory powertrain warranty, have the dealer check it out.

 

[theblet]

piston slap also gets amplified under load, and usually fades when rpms come down. can you take a sound clip while someone is revving it?

 

[midshaw]

I may have something similar. I hear 5-7 loud clicks/ticks during startup every time both cold and warm. Here is a video. The clicks are louder in person but go away in a few seconds. Do you hear anything alarming?

The second clip is my engine after it has been on for a minute or two.

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[yankeefan31569]

sounds like mine, might wanna take it in sounds like the imfamous
hemi tick ,
exhaust manifold bolt broke

 

[midshaw]

It’s headed in tomorrow to get checked out. Weird thing is that I don’t hear anything after the initial 5-7 clicks/ticks. The second video shows the engine running warm.

I do not have a trained ear for engine noises so maybe someone here will hear something I don’t.


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[SD Rebel]

It’s headed in tomorrow to get checked out. Weird thing is that I don’t hear anything after the initial 5-7 clicks/ticks. The second video shows the engine running warm.

I do not have a trained ear for engine noises so maybe someone here will hear something I don’t.


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By chance, do you only hear this clicks/ticks at specific scenarios, like the one mentioned in the manual below, circled in the left. This happens to me, if I turn on my truck for a short time, like say moving it a few feet or running the engine for a minute and then turning off. I get loud ticking for 3-5 seconds on the next restart. The manual mentions it can last 30 seconds, but it's usually just been a few for me in the outlined scenario.

 

[JLaw297]

I may have something similar. I hear 5-7 loud clicks/ticks during startup every time both cold and warm. Here is a video. The clicks are louder in person but go away in a few seconds. Do you hear anything alarming?

The second clip is my engine after it has been on for a minute or two.

Sent from my iPhone using Tapatalk

The 5-6 clicks I think is normal for a cold start, I hear it on almost every cold start 2019 or newer Ram exhaust video. Mine does it every time with the same consistency and time between clicks as do the ones in the videos.

Couldn’t make out anything from the second video though. I have appointment to drop mine off at the dealer next week for them to take a look at my cold knock. Will report back on their findings.

 

[midshaw]

Just got back from the dealer. Everything checked out perfectly with no broken bolts or exhaust manifold leaks. He said it looks like a brand new Ram.

All they did was update the uconnect software and document my concern on the back glass pressure mark (where they typically break). Other than that I’m feeling good!


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