CashDudeHomie

iTrader: (5)

First of all let me just say thanks for always helping me try to diagnose my problems. I am posting this on both sites, not because I don't trust you guys, but because there is so much talent and experience that I know someone out there has had this exact problem. It should be easy to diagnose because of how evenly spaced the taps are. This is idling around 650ish.

Here is my original post:

I noticed this sound this morning. It was loud enough for me to hear it in the cab. I checked the valve springs and they are ok. Then I noticed it is louder from below. The sound increases proportionally with engine speed. It seems to be coming from the rear of the engine. I do have oil pressure. Now the truck is parked until I figure out if it's safe to drive.

Does anyone know what it sounds like? I hope it is not something serious

It's a 2003 6.0 with over 100k. The sound just appeared out of nowhere this morning. It did not go away when the truck warmed up.

http://www.youtube.com/watch?v=DiZwsrWKHoc

fyrflt

It sounds like my car... which is in the shop getting a new engine due to spun rod berrings. Id have that opered up and looked at ASAP.

Schwanke Engines

iTrader: (1)

I would just check your torque converter bolts, just because if that is all it is, it would be awesome, but yeah, sounds like a rod knock.

CashDudeHomie

iTrader: (5)

I looked at some rod knock vide on YouTube and they are much louder. But mine could just be in the early stage of failure and will get louder.

If it is a rod knock, would it have metal in my oil? I can cut the filter open and check.

I noticed it taps about 2.5 times per second at idle.

What does a bad lifter/rocker/pushrod sound like?

I can't wait to get off work so I can poke at it some more.

mwg2600

Check the torque converter bolts before you go any further.

CashDudeHomie

iTrader: (5)

NEW VIDEO

Checked TC bolts and they were fine. Removed valve covers and everything looked fine. Ran it with them off and the sound seems to be coming from below the heads. It is louder from below the truck.

I timed the sound and it is approx 360 taps per minute - half of the engine RPM so another member told me this means it is valve train related. Could this be a lifter noise? What happens to lifters when they fail or wear out? Do they sound this loud?

http://www.youtube.com/watch?v=7hSWcpxP3jo

CashDudeHomie

iTrader: (5)

Bump for new video.

rich5368

iTrader: (2)

Could be the classic piston slap that most gm trucks get eventually. Not a big deal if that's what it is. Does it go away after it warms up? Mine both do it and one's got 165k on it and runs like a dream.