Tap Tap

[twenty14hemisphere]

***video added on post #19 ***
Got a 2014 Ram Hemi 5.7. Just under 9,000 miles and had her for about 8 months now. Love it. I know the over talked about hemi "tick" is a common topic. And yes, my truck seems to have it now. It doesn't bother me.

However, twice now I have heard a very loud knock, like a metal on metal knock on start up. Once was the first start up of the day, and a week or so later after it was sitting for about an hour. It was loud enough for my g/f who was standing outside to cringe and ask what was wrong. It lasted about 5 seconds both times.. I listen for it now every time I start it up, and now I don't hear it. Only those 2 times. I'm sure it will happen again at some point. I am taking her in next week to get checked out, they have already told me that there is really nothing they can do to check it if it doesn't do it with them.

My question is what would cause this type of issue to be so sporadic? And what should I make sure they do/check at the dealer? Would it not be acceptable for me to make sure they drain the oil and also check the oil for damage?

Oil changes about every 3,000 miles btw and at this dealership.

thanks in advance

 

[twenty14hemisphere]

getting irritated

just an update to this thread in case anyone can help out.. the knock sound i get now happens almost every cold start up.. except now it does it after the truck idles down all the way down to low idle speed.. it is almost more like a rattle or slight knock.. not sure how to explain it.. the sound goes with the rhythm of the engine but doesn't quite hit every single time.

I took the truck to the dealership and they blew me off and said because they could only hear it by standing outside the truck, and not when sitting in the truck, that it was not important enough to fix.. they requested that I drive the truck another 2,000 miles and that hopefully it will get worse.. at which point one of their "master mechanics" might be able to decide what the knocking is.. This is completely unacceptable to me. Brand new truck.. 10k miles on it..

 

[kg93]

try an independent shop or different dealer? doesn't sound like they have master mechanics if they cant tell you now lol. goodluck though!

 

[twenty14hemisphere]

try an independent shop or different dealer? doesn't sound like they have master mechanics if they cant tell you now lol. goodluck though!

yes, i am going to try to find a different dealer.. the only problem is the next closest one is 40 minutes away.. and they have to keep it over night just to try to hear it bc it is only on cold starts. which puts me with no car to drive to work. so having issues coordinating that aspect of it. I am not going back to the original dealership i do know that much.

 

[kg93]

I would also take a video for everyone here. It would make it a lot easier to understand the sound and might help pinpoint it

 

[SlowRoller]

it is almost more like a rattle or slight knock..

Lifter,,,?

 

[twenty14hemisphere]

I do have a few videos on my phone of the noise. Of course it is not as clear on video over all the other background engine noise, but it can still be heard. Especially with a good set of earphones. I'll try to post a few videos when I get to my home computer this week. Can't upload the video to this work computer unfortunately.

 

[Burla]

If it is lifter tick a high moly oil like Redline or Motul can help, it has for me and many board members, most who have tried it, but not all. Also, equally important is oil filter choice, none better then Royal Purple. Read the syn thread in my sig and see if you learn something new. read up on Moly as well -click this link, most oil have about 60ppm, but Redline and Motul have over 800ppm. People are probably tired of hearing it, but for new guys or guys with low post counts that may have not got this info, it is good knowledge. You would not need to change the oil for 15k miles with either Motul or Redline and a RP filter, but if you wanted an option that is conventional oil Penzoil Yellow Bottle has a very good Moly count as well.

If it is lifters, other option is to replace. If you ignore it hopefully it collapses while you are still under warranty. But just imagine what happens when a lifter doesn't lift. The cam lobe hits the lifter and it doesn't lift, something has to give either the roller part of the lifter or the cam lobe.

 

[SlowRoller]

I wonder how many ppm a shot of this stuff would give ya,,,

http://www.amazon.com/Liqui-Moly-2009-Anti-Friction-Treatment/dp/B003U4O414

 

[SlowRoller]

.. they requested that I drive the truck another 2,000 miles and that hopefully it will get worse.. at which point one of their "master mechanics" might be able to decide what the knocking is.. ..

Sounds like you've been given permission to drive it w/o worrying about a 'you should not have driven it' problem should there be any mechanical failure. In a way, that's better than them telling you lo leave it with them for (????) long in the hopes that they can replicate/diagnose/repair.

It sounds like the noise has changed in both it's tone and run time,,, Drive it like you always do/see what happens.

Almost sounds like a defective anti-drainback valve in your oil filter,,, allowing varying degrees of drainback/drystart....

 

[Burla]

That is a different Moly. The oil used in engine oils is organic oil soluble Moly, that product is Moly in suspension. I'd try a high moly oil first if it was me.

 

[drittal]

But just imagine what happens when a lifter doesn't lift. The cam lobe hits the lifter and it doesn't lift, something has to give either the roller part of the lifter or the cam lobe.

Basically in your scenario it is the lifter that is giving. If a hydraulic lifter isn't lifting that means it is collapsing when the cam is pushing it against the pushrod to open the valve which means the valve isn't being opened.

If I am not mistaken, our mds works in this way.

 

[drittal]

Double post.

 

[Burla]

Basically in your scenario it is the lifter that is giving. If a hydraulic lifter isn't lifting that means it is collapsing when the cam is pushing against the pushrod to open the valve which means the valve isn't being opened.

Video Lifters 5.7.

The lifters are still lifting with hemi tick, they just aren't lifting smoothly because of poor lubrication. A bunch of metal on metal wear in going on.

 

[SlowRoller]

In the case of the OP, and just by the 'vibe' I'm getting from his descriptions, IMHO,,,, it's unclear that his noise could be cured by Moly,,,

The discussions regarding organic oil soluble Moly vs MOS2 are quite lengthy,,, BITOG has a lot of opinions on both flavors!

 

[drittal]

You stated "imagine what happens when a lifter doesn't lift... ...something has to give..."

A hydraulic lifter will still move up and down in the lifter bore as the cam acts upon it, but if it isnt lifting it means it doesnt have the hydraulic pressure inside it to force the valve open.

 

[SlowRoller]

Basically in your scenario it is the lifter that is giving. If a hydraulic lifter isn't lifting that means it is collapsing when the cam is pushing it against the pushrod to open the valve which means the valve isn't being opened.

If I am not mistaken, our mds works in this way.

Video Lifters 5.7.

The lifters are still lifting with hemi tick, they just aren't lifting smoothly because of poor lubrication. A bunch of metal on metal wear in going on.

I assume y'all are talking about something seen only in a link provided in an earlier post,,,

(Sorry OP)

The biggest difference in MDS mode is that the solenoid opens and allows the lifter to bleed off it's internal pressure instead of holding/using that same pressure to open the valve. Still plenty of oil going through the lifter either way.

Pretty slick system, and actually a ~copy~ of sorts of a previous Mercedes MDS system.

There have been lifter failures on 4th Gens,,, Needle bearings go south and the 'roller don't roll no more',,, What's left wears away at the cam,,, BUT, it's typically not something that 'goes away' or is unnoticeable.

It will be nice to hear what is determined in the OP's case.

 

[Burla]

You stated "imagine what happens when a lifter doesn't lift... ...something has to give..."

A hydraulic lifter will still move up and down in the lifter bore as the cam acts upon it, but if it isnt lifting it means it doesnt have the hydraulic pressure inside it to force the valve open.

ok you win.

 

[twenty14hemisphere]

video

heres the first video i was able to upload of the sound. the phone camera is being held in the drivers side wheel well because that is where the sound seems loudest.. let me know what you think.

https://www.youtube.com/watch?v=v8AAJ6LlUfE

heres a second one its a little louder in this one i believe

https://www.youtube.com/watch?v=iIm-_SGUqtw

 

[SlowRoller]

Forget your oil/ oil filter. Check yer studs,,,