Rod Knock?

[USMCFieldMP]

Okay, I bought this DSM last month and my friend fixed it up a bit for me while I was gone. He shot me a message before I came home saying that it has Rod Knock. Soooo, it has sat around since then. Today I was feeling spunky and wanted to hear it for myself, to confirm, just in case it was actually just the lifters (I've heard stories of some noisy fkn lifters). I made this video today... I'm pretty sure that it is Rod Knock, though.

The bearing were replaced about 50-70 miles ago though and oil pressure has been good ever since... so I am kind of hesitant to just tear it apart and replace stuff without knowing the cause. I'll probably drop the pan this coming weekend and check out the insides. Maybe check the oil pickup to make sure it isn't clogged, but I think that would have shown up on the Oil Pressure Gauge (I have an aftermarket Autometer one).

Race Vids :: DSMIdle.flv video by USMCFieldMP - Photobucket

The noise is MUCH louder behind the block than it is in the front. I don't know if this is typical or not.

Any input? I've never dealt with Rod Knock before.

 

[viprez586]

Almost sounds like a collapsed lifter.
Anyway it's a good idea to replace the lifters with the revised 3mm oiling ports. Make sure you prime them before putting them in though.

Get a long screwdriver and put your ear on the end - while resting the other end on the suspected area of noise.

Did you make sure you got the right bearings and take measurements?

 

[USMCFieldMP]

Almost sounds like a collapsed lifter.
Anyway it's a good idea to replace the lifters with the revised 3mm oiling ports. Make sure you prime them before putting them in though.

Get a long screwdriver and put your ear on the end - while resting the other end on the suspected area of noise.

Did you make sure you got the right bearings and take measurements?

There lies the problem. I didn't do the Bearing Replacement. The guy that I bought it from did. He melted a piston in his block. So he bought a new shortblock and replaced the Rod bearings in it.

I'm starting to wonder if he bought a block that already had a spun bearing... and he just replaced the bearings. I'm not sure, I'm probably gonna put the Valve Cover tomorrow to see if I can see anything. Possibly even drop the Oil Pan. Iono... Iono if I'll have enough time.

 

[95blackGsTurbo]

Easy test for rod knock is to remove the spark plug wire on each cylinder 1 by 1. This will take the combustion load off the bearing and the noise will go away if it indeed is a rod knock.

 

[USMCFieldMP]

Right, I do remember reading that. I shall do this test later on.

Clicking persists no matter what spark plug wire is removed. I'm gonna try and get it into my garage to pull the Valve Cover tonight. If not, it'll have to wait until the weekend, since I have to report back in tomorrow (military).