I'm having this knock, kind of like a rattle I would say. What do you guys think this is? Its been there as long as I have owned the truck, used 20-50 and 10-40 weight oil in it it still sounds the same. Just curious every mechanic I have taken it to they don't know.

Video 1

Video 2

 

Sounds like bottom end noise, like a worn out rod to crank bearing. How's your oil pressure?

 

I cant see the videos...

 

I ​​Agree that is most likely rod knock. If the people you took it to couldn't tell you this you probably don't want them working on it anyway.

Take a mechanics stethoscope and listen along the bottom of the block and oil pan junction, it will get louder or quieter as you move towards and away from the source

You can also ground or unplug the spark wires one at a time.

Judging by how loud that is you've done more damage than just spun the bearing and are running it dry, it sounds like the bearing is gone completely.

 

I do not have a gauge for the oil pressure, but the light stays on for a sec or two after start.

This has been there since I bought the truck 5 years ago. The truck runs, but it shakes at the lights and it sounds like a diesel, Lol. In order to fix this, it will require a rebuilt, is that correct? Also will this break on me on the road and live me stranded or just sound and act like this for ever? I have been changing the oil religiously, have been staying with 20-50 weight feels like it runs smoother. Also been adding in oil stabilizers ever other oil change.

@swampedout Sorry you can t see the videos. They work on my end, they are mg4 if that helps.

 

Once a rod bearing is damaged it's anybody's guess when it will cause a catastrophic failure. Thick oil and stabilizers will help, but they will not solve anything.
Yes, it could break while you're on the road; it might be tomorrow, it might be in 3 years.
The way I see it, you've got 5 years on a bad rod bearing (or lack of a bearing at this point), if it's within your means, get it fixed.

 

Was the engine cold or hot in the video? Is it quieter when at full operating temp? Does it consume a lot of oil?
As Co says, unplug spark plug wires one at a time to isolate which cylinder.
It could be a wrist pin, cracked piston, not a bearing. I don’t know how you could drive 5 years on a bad rod bearing.
My truck has wrist pin noise, sounds bad when overnight temps drop and you put a load on it before it’s up to temp.
you can’t fix it without a complete teardown. If rod bearing, you could go in through the oil pan.

 

It sounds like what you're experiencing is piston slap. As your engine warms up and tolerances tighten it goes away.
Bearings and wrist pins are the opposite, they'll be quiet at first when the oil is still cold and thick, but as the engine warms up and the oil thins out you'll start to hear that metal on metal.

 

In the video the engine was sitting for maybe 1 hour, after driving on the freeway for about 12 miles. The noise never goes away at idle speeds at revs it goes away completely. I thought it was a worn out chain guard.

 

It's a little hard to tell from the videos. At the very least, remove the valve cover, get a strong light and have a real good look at the timing chain & guides. When you say the sound goes away at revs (I assume you mean engine speeds faster than idle?), that's usually a sign of a wron out timing chain or broken chain guide, usually the driver's side guide. More rarely it could be the tensioner not fully extending to take up chain slack, but more likely your timing chain is just worn out and the tensioner cannot make up for it. Do what Co says, locate the noise to a more specific location. If you can narrow the noise down to the front driver's side of the engine, at the timing cover about half-way down, it's the chain and/or guide. If not it's something else.

Another thought before you pull the valve cover. Get a timing light on it and check the timing mark on the crank pulley while it's running/idling. If the mark isn't in a steady location with every flash but jumps around, it's likely the timing chain. My 20R did this just before the chain jumped a tooth, timing mark jumping all over the place. New timing chain set installed and the timing mark is rock steady at idle.

 

Thank you guys so much for all you inputs i'm going try this stuff out. I will return with some data in a few days.