Hemi piston slap?

[shadango]

Hi all

So for you guys who have done modern Hemi swaps I have a question --

Have you had any issues with cold start piston slap noise in stock Hemi engines?

I own a 2012 Ram with the 5.7 hemi...owned since new....and since about 3-4k miles it started making a loud "diesel like" low end noise....loud on startup when cold, much louder as outside temps drop.....putting into gear when cold makes it even louder...By about 15 miles or so the engine has warmed up enough to not make the noise.

Had it to the dealer several times over the first 7 years of ownership -- "cannot replicate issue" was always the reply.

SO right before the warranty ran out, at 45k miles and 6.5 years last year around this time, I took it down and left it sit overnight in the cold and met the service rep and the lead mechanic in the AM to hear it.

NOW they hear the noise.

They had my truck for like 2 months and finally did a warranty engine swap.....

No noise for the first 3-4k miles and then it was back.

I did some digging and Arrington Performance says that Mahle (the OEM for the pistons) used al anlloy per Chrysler specs that had high expansion rates and therefore requires higher piston to wall clearances when cold and therefore makes noise. That and the location of the wrist pin supposedly.

But my question to you all is --- have you head the same thing with your transplants?

It drives me nuts! Love the truck and the engine except for that.

In my old LA engines, a noise like this is BAAAAAAD. LOL

Here is a link to a video I made of my noise....



Any advice would be appreciated.

 

[Johnny Mac]

I own 4 late model hemis. They all have differing levels of valvetrain noise from zero, to near THAT when cold. I have never heard hemi and piston slap in the same sentence. I do hear lifter complaints, although I have never had any real problems
Mine are..
36000 miles
78000 miles
109000 miles
197000 miles

Put a quart of Lucas stabilizer in it to displace one qt of oil.
Bet it helps. Easy $15 test

 

[Stephen Mulkey]

Hi all

So for you guys who have done modern Hemi swaps I have a question --

Have you had any issues with cold start piston slap noise in stock Hemi engines?

I own a 2012 Ram with the 5.7 hemi...owned since new....and since about 3-4k miles it started making a loud "diesel like" low end noise....loud on startup when cold, much louder as outside temps drop.....putting into gear when cold makes it even louder...By about 15 miles or so the engine has warmed up enough to not make the noise.

Had it to the dealer several times over the first 7 years of ownership -- "cannot replicate issue" was always the reply.

SO right before the warranty ran out, at 45k miles and 6.5 years last year around this time, I took it down and left it sit overnight in the cold and met the service rep and the lead mechanic in the AM to hear it.

NOW they hear the noise.

They had my truck for like 2 months and finally did a warranty engine swap.....

No noise for the first 3-4k miles and then it was back.

I did some digging and Arrington Performance says that Mahle (the OEM for the pistons) used al anlloy per Chrysler specs that had high expansion rates and therefore requires higher piston to wall clearances when cold and therefore makes noise. That and the location of the wrist pin supposedly.

But my question to you all is --- have you head the same thing with your transplants?

It drives me nuts! Love the truck and the engine except for that.

In my old LA engines, a noise like this is BAAAAAAD. LOL

Here is a link to a video I made of my noise....



Any advice would be appreciated.

My advice is earmuffs when it's cold ;)
I'm with Jonny Mac. I have a 2005 Powerwagon at home that i bought new and will keep till death due us part, it has 283,000 miles. I just traded in a 2014 Sport with 230,000 miles and my new 2019 with 22,000 and have a respect for the 5.7 Hemi. Keep the oil chaged and drive the hell out off it. My 2 cents.

 

[brian6pac]

Here is the problem and I have it also with my LS, It's carbon on top of the pistons and when cold the carbon is hard, the piston makes contact with the head cocking the piston and making the skirt slap the wall. When the temp comes up operating temp the carbon gets real soft and you don't hear it. You can fix it with water injection when hot. If you get the motor to operating temp fix the throttle to run about 2500 RPM find a vacuum hose you can use to suck up the water, you need to restrict the hose to about 1/16" hole and stick it in a bucket of water and let it run, when the carbon starts breaking up it will smoke bad but it is normal and wont hurt any thing as long as you keep the water flowing through a restricted hose. I would start with a quart of water and see if it does the trick. Check the oil level before and after and check for water in the oil, you shouldn't have any if you inject it slow. Take it for a fast run down the highway when finished. Change the engine oil if you think it has any water in it. It may take a couple times to get all the carbon out. I worked for Cadillac and in 2003 we had to do this for the same reason, then they came up with another contraption to get the carbon out, it didn't work any better. Then came the piston change to a new design. I changed the pistons in about 50 Northstar engines, That fixed the problem.

 

[Syleng1]

One of my 2018 6.4 2500 have been cold knocking since new.
Smells like antifreeze after a hard drive and shut off. Dealer states it’s normal.
Always running the 0w20 oil from Pennzoil like factory says. Never down on oil or antifreeze. Quirky Chrysler’s.
When cold sounds like a rod is knocking.
I start it up and run away till it warm.
Dealer head tech told me it’s something to due with lifter noise. Smell is coolant cap release.

40k on that truck and it does it every morning.

 

[Krooser]

This was noisy...