I have a clatter/ chatter that only shows up when the engine is at speed, no sound when accelerating or decelerating, only starts at 45 mph or so and after the engine is warmed up. There is no sound when starting cold or hot [ like rods or mains]. I checked the flex plate, nothing wrong there. I pulled rocker covers and all is normal with tappets and lifters.It started around 30000 miles ago and has gotten a little louder recently. It has good power and uses no oil. how would I check for broken rings,loose piston pins or broken piston skirt? Thank you for reading from a new member
Richard

 

what you need is a the tool like what doctors use the listen for your heart I know what it's called I just can't seem to get the spelling right. it sounds like the oil can't return to the pan fast enough. so I'm asking you if the oil pressure drops below normal after it's warmed up and running at speed.

 

Oil pressure remains high when hot. when I had covers off engine was spotless on topside anyway ,so I`m thinking no restrictions for oil return.

 

you still need to get one of those scopes that has the rod on the end and while it's running you can put it in certain spots on the engine and determine where the noise is coming from. it could be nothing more than a spark knock or a lifter that's getting weak. depending on where the noise is coming from is what is causing all the noise. and if you don't find that out then you may have an engine with little life left in it

 

Right now I am putting new plugs in while I have access, that # 1 on drivers side is a bear!!!!!! I do have a stethoscope but could not center the sound, it`s loudest while running down the road. I`m going to try driving it with the "doghouse" out see if I can tell anything.

 

the only way to check for bad rings worn wrist pins is to take the engine all the way down to them which costs money and time. another thing that could cause the noise is piston slap.

 

one other thing that you can test is for bad u-joints they are known to knock when they are worn out and get loose

 

While under the van I noticed rubber coming out of my motor mount so I have one ordered and it will be a couple of days before road test with the " doghouse" out.

 

that's where your sound is coming from when under a load the fan is hitting the shroud. but then again I don't know much about anything either

 

Grindman, you're gonna love this,
Good thing there are no experts here!
Definition of expert;
A person who learns more and more about less and less until he knows practically everything about almost nothing at all !
Have a good day.