Can some explain to me exactly wut a spun rod bearing is, how it is caused, and how u know if u have one....Jw

 

no oil or bad oil

 

There is a cylinder of metal, in two parts pressed against the rod on the crankshaft. These metal pieces are specially designed to give a certain about of clearance to the crank from the rod. This clearance is essential for oil pressure.

Too loose of a bearing and oil pressure drops making metal to metal contact and ultimately failed bearing.

Likewise a bearing thats too tight wont spin right and cause massive friction and also ruin your bearing.

Bearing failure is usually caused by low oil pressure, high heat, and over revving without proper lubercation..

Hope that helps

 

a rod bearing is a bearing that is between your rod and your crank. They are supposed to stay stationary and give the surface of the crank something to spin on as well as clearance for oil to allow the piston to move up and down as the crank spins. A spun rod bearing is a bearing that is not doing what it's supposed to and has shifted. THis could be caused due to debris getting caught between the bearing and the crank surface, or more commonly by lack of oil getting to the bearing surface and causing excessive friction. Either way, the bearing is toast and the crank becomes scarred either requiring resurfacing (if posible dependant on amount of damage done) or replacement.

 

it will sound like a knocking noise coming from the lower part of the block. It will usually get louder as you step on the gas more. Once you hear it...shut the car down and tow it home. The longer you drive, the worse the damage gets...possibly leading to a rod being thrown thru the block.

 

Too much rpm, lack of oil/oil pressure, and even too much power can cause spun rod bearings.

 

low oil. I spun one due to a oil leak.

 

Yep, lost my stock block to rod knock. I'm not sure of the actual cause. Could have been power, revs, oil level / preasure, or both. I noticed an slightly audible "tapping" sound coming from the lower portion of the firewall. It really didnt sound like it would have been much of an issue. Over the course of a day, it got louder, and louder, and louder. It began to sound like a "knocking" sound. I drove the car to my mechanic and he gave me the bad news.

 

Yup i herd that exact tapping noise your talking about after a 90 Degree swooping turn at 90+mph... at part throttle.. Needless to say the car got parked and trailored to the best shop around.. Saved everything Could've just replaced the spun bearing through the oil pan.. But **** what'd i do..


2.3 baby

 

quick diagnosis procedure: with car parked and ebrake on, run engine to the RPM where it knocks. Put trans in gear and s l o w l y let out on the clutch until the clutch engages and then stop. If the knock goes away when it's loaded against the ebrake, it's most likely a bad rod brg. Unfortunately this diagnosis has worked for me (non 4G63)