paawwl

I know there are several posts on here about lifter tapping and piston slap but I can't find any with video posts so I can compare to my truck.

I have a 2004 Silverado Z71 5.3 on cold mornings this is what is sounds like:

https://www.youtube.com/watch?v=fRz9...ature=youtu.be

Once the truck warms up (~5 min) then the noise goes away:

https://www.youtube.com/watch?v=HFsM...ature=youtu.be

What do you guys think the noise is? It sounds terrible to me is there anything I can do to fix the problem or does it sound worse than it actually is.

Thanks for the help

bandit_601948

that sounds like the lifters to me ! do a good oil change and put some good conditioner in the oil ! myself i like ( BG oil conditioner ) sounds like the lifters are draining off overnight !

paawwl

Here is another video with the hood popped and moving around maybe this will help pinpoint the location...

https://www.youtube.com/watch?v=6Xyi...ature=youtu.be

hicksvilleshick

Ok to me that doesn't sound like lifters, far far tooooooo loud.

sounds more like an exhaust leak to me (thru laptop speakers) you might look that way and hope for the best otherwise that (to me) sounds far louder than lifters would ever be.

maybe something like a donught gasket or something isn't sealing up til it's warm... :dunno:

edit: after the 2nd vid, seems to be coming from the passenger side...

in2pro

That is pretty loud... My dad had a Mercury Marquis many years ago that had a sound like that and it turned out to be a connecting rod cap.. apparently one of the rods was missing one of the retaining nuts for the cap... apparently came from the factory like that... it was later found in the oil pan after the rod gave way

I'd try to isolate the sound area with a mechanics shtyescope, or a length of dowel rod against your ear and various parts of the engine (exercise care)

Allan In NE

You'd better get that thing to a mechanic before she comes totally unraveled. Sounds like a wobbled wrist pin or broken piston to me.

Allan

paawwl

Even though the noise goes completely away once the engine temp goes up?

If it was something as serious as you stated wouldn't the noise be constant not go away?

kevinkpk

Sounds like piston slap to me. I have a 5.3 that had that issue, stops after warmed up. Two pistons replaced due to undersize. I will NEVER understand how a piston skirt could wear.......

67Motorcat

Yep,that is the dreaded piston slap that raises it's ugly head when the weather gets cold.

My 5.3 will do it as well from time to time,but it doesn't really get that cold where I live most of the winter and quits after about 30 seconds.In summer it does not do it at all.

Try using some lighter weight Oil during winter and see if that helps a bit.

Hell,Ive' got over 200K on mine so wouldn't worry too much...just don't drive it until the sound goes away.

Allan In NE

That's more than just 'piston' slap. It's got a "double" rap to it.

AND, it isn't going comletely away hot. I listened to your other video also. Somethin' is still doing a low frequency 'knock'.

Allan