Engine knock after 1 week cold start

[dvanderk]

Bit of an issue with my 5.7 hemi motor. If I leave the engine off for about a week then turn it on, it makes the noisiest cold start *clacking* sound. If I build oil pressure by holding the gas pedal down then starting it, it turns over the motor without actually starting the truck. If I perform this operation 2-3 times then start the engine, there is no noise. My thoughts are oil pressure in the head but could definitely use your opinions on this matter.

 

[HarryS]

What engine?

 

[dvanderk]

Sorry, I just edited the post to include the 5.7 hemi engine.

 

[rzr6-4]

Sorry, I just edited the post to include the 5.7 hemi engine.

I have this on occasion as well as I may not drive my ram for a week or two at a time. I was told by someone on here that the hydraulic lifters can leak down over time and need a few seconds to pump back up.

 

[Burla]

It's either dry lifters or cold piston slap, if the ambient temp is 30f or lower or close, it very well could be cold piston slap. If it is lifters look at lubrication strategy, both moly and esters can help, if it is cold piston slap nothing you can do other then use a 0 winter rated oil or use a block heater, even at 30f.

 

[dvanderk]

It's either dry lifters or cold piston slap, if the ambient temp is 30f or lower or close, it very well could be cold piston slap. If it is lifters look at lubrication strategy, both moly and esters can help, if it is cold piston slap nothing you can do other then use a 0 winter rated oil or use a block heater, even at 30f.

I'm located in Florida (warm weather).

 

[Burla]

I'm located in Florida (warm weather).

most likely not piston slap then, try adding 15 ounces of biotech see if it does anything.

 

[jws123]

Sorry, I just edited the post to include the 5.7 hemi engine.

Its just the ****** mds lifters they bleed down easy the oil additive does help

 

[dvanderk]

Its just the ****** mds lifters they bleed down easy the oil additive does help

What oil additive helps? I'm currently using Mobile 1 synthetic oil.

 

[CanuckRam1313]

What oil additive helps? I'm currently using Mobile 1 synthetic oil.

** EDIT - use this at every at every oil change.
Also use a premium synthetic media oil filter like the Royal Purple 20-820 or the Fram XG2.

 

[dvanderk]

View attachment 554741

** EDIT - use this at every at every oil change.
Also use a premium synthetic media oil filter like the Royal Purple 20-820 or the Fram XG2.

This additive? https://www.amazon.com/Lubegard-309...&sprefix=lube+gard+engine,aps,135&sr=8-2&th=1

 

[jws123]

This additive? https://www.amazon.com/Lubegard-30902-Tech-Engine-Protectant/dp/B0002JMLRE/ref=sr_1_2?crid=37U11BTUDMWZS&dib=eyJ2IjoiMSJ9.ZPgyVYu06nz8J0yh7_kbL4QiV089vjyUoN-7k7WFQmr2btXIekljSWEgkaigLbZ3OwaLytqGvWZ4zRvjzC7rQx8naDcU-gprNLjDVPQmjTWfP1Rlf1mySNHgWcU4zdlShIETXa3JA0r6d7pF33PZa5-3H2HZEKyBB1UFvPa54-NZziZCbT3p8_VwybObm-3VR4uHXe0jTvwKIlk4G1HpRim6zbkByF9dxpytVeLd_cLpJ3vd6D-_x6a6CXb2vKEZ1UnyCBHj_25IwBFvGOVj-iDVcgVLeg31ETRs9zKEm4k.Iix7OFJ5ztx7QWn7S7zf-5I452T_TdarNmWlJtGvejY&dib_tag=se&keywords=lube+gard+engine&qid=1731614949&sprefix=lube+gard+engine,aps,135&sr=8-2&th=1

yes

 

[CanuckRam1313]

This additive? https://www.amazon.com/Lubegard-30902-Tech-Engine-Protectant/dp/B0002JMLRE/ref=sr_1_2?crid=37U11BTUDMWZS&dib=eyJ2IjoiMSJ9.ZPgyVYu06nz8J0yh7_kbL4QiV089vjyUoN-7k7WFQmr2btXIekljSWEgkaigLbZ3OwaLytqGvWZ4zRvjzC7rQx8naDcU-gprNLjDVPQmjTWfP1Rlf1mySNHgWcU4zdlShIETXa3JA0r6d7pF33PZa5-3H2HZEKyBB1UFvPa54-NZziZCbT3p8_VwybObm-3VR4uHXe0jTvwKIlk4G1HpRim6zbkByF9dxpytVeLd_cLpJ3vd6D-_x6a6CXb2vKEZ1UnyCBHj_25IwBFvGOVj-iDVcgVLeg31ETRs9zKEm4k.Iix7OFJ5ztx7QWn7S7zf-5I452T_TdarNmWlJtGvejY&dib_tag=se&keywords=lube+gard+engine&qid=1731614949&sprefix=lube+gard+engine,aps,135&sr=8-2&th=1

Use the 15oz bottle per oil change.

 

[Burla]

Use the 15oz bottle per oil change.

or use the 32 ounces and use half the bottle and save 10 smokes? Actually 13 smokes but who's counting.

 

[CanuckRam1313]

or use the 32 ounces and use half the bottle and save 10 smokes? Actually 13 smokes but who's counting.

There ya go being all financially smrt

 

[DanM]

i have that noise also. Use to use Mobil 1 and now Pennzoil ultra. Less of an issue. Some one told me or i read there's a problem with the oil pickup.

 

[N0NAMETOGIVE]

Cold flood mode is enough, besides RAM states it as normal and harmless for the sound. My truck sits for months and oil analysis is looking good, so I don't mess with additives or rituals outside of 5k intervals on Pennzoil.
108k miles.

 

[Taifun7]

Lets keep it simple and ask about the type of oil your using, along with what brand name oil filter and does it employ a anti drain back valve and how long since your last oil change. I have to agree with the first few responders who suggested loss of oil pressure in the upper cyl. head.

 

[JC4041]

Before starting....hold the gas pedal to the floor and crank it. It won't start, but get oil moving around.

 

[Marshall]

These days mine may sit for a week or more, Never had that problem, I am still low mileage.
I don't think OP ever said what his mileage is , when was the last oil change?
Did it just start now? maybe one lifter is going?