Hi all, new to this thread. I've been reading through the mforum and found that the ticking noise coming from my hemi on cold starts is completely normal. Im OK with that. What Im not so ok with is the loud knocking noise on cold start up.
It started making this noise along with a check engine light and very rough running. I had the code checked and was a misfire. Determined a bad coil. Now the truck runs great, except right after cold start. If it sets overnight Ill start her up and it shakes with a poor idle and loud knocking noise for a couple of minutes. Then after a few minuts it is back to normal...what gives. Here is a youtube link to the knocking noise im talking about. Any help would be greatly appreciated.

Here is a youtub vid of what it sounds like after cold start.
http://www.youtube.com/watch?v=KnHWH...eature=related
and another. http://www.youtube.com/watch?v=i8ODYx_z_rU&NR=1

 

its a 2006 Dodge ram 1500 5.7 hemi 2wd.

 

I can't say that I have ever head that noise before. Definately doesn't sound healthy.. It only does it when it's cold?

 

to make a very uneducated guess...... a lifter smacking the valve cover?

 

Thats right, only does it like when it has sat overnight, first start of the morning i get a rough idle along with this knock noise. Once the truck warms up, the noise is gone and the truck runs perfectly fine. I dont get it???

 

Thats weird.. Has me thinking possibly an oil circulation problem? Possible spark knock? I had a 95 chevy z71 that did that too kinda like that and I just had a rocker arm loose on that..

 

Thats a wierd knock - I dont think its really nasty though. The timing of it might indicate a bad lifter but I would check everywhere else for a mechanical interference first - fan, belts, pulley etc. Is it possible you dropped something onto or into the engine?
Steve

 

weird right, I havent dropped anything into the engine. It only does this for a few minutes after cold start up then quiets out and runs like a normal truck. Checked obvious interferences and found nothing. I think ill take off the "hemi hat" cover and try to hone into the noise tomorrow morning.

It just drives me crazy because it sounds bad to me or at least in comparrison to what im used to. The worse part is the timing. because it only does this on a completely cold start only for a short while it is becoming a PITA to pinpoint. All ideas appreciated.

 

Get an analogue oil pressure guage and tap into the oil sender port with a "T" and check the oil pressure at startup. Sounds like a collapsed lifter, or a lifter roller that is dry.

 

what should the oil pressure be at start up. How do I figure if its a collapsed lifter, what would be the fix? thanks for your help. you guys rock.