Rod knock - Can this sometimes be an easy fix?

[SchlockRod]

I just finished putting the reman head on my '92 3-cylinder. I did this to fix what I was certain was a clacking lifter (because it was at half crankshaft rotation speed). Lo and behold, the same loud knocking is still there, and I realize that a rod knock would also only occur every other rev if it is a function of firing events. When I put the screwdriver stethoscope to the cam cover I was certain the noise had to be directly under there; I could feel it in the blade & handle of the screwdriver.
Anyway, I was wrong and I'm wondering if sometimes just dropping the pan and changing out a bearing can fix a rod knock. A guy at work who wrenched profesionally said sometimes you can get away with that if it isn't too far gone.
Any advice?
Thanks in advance.

[bansheetaz]

yea sometimes that works

[Infinitrium]

As long as the rod bolts aren't stretched or loose, then new rod bearings would most likely cure the knock. You might as well do all 3 rod bearings, and while you have the oilpan off, clean off the oilpump pickup screen.

[corning_d3]

Sometimes it works.. But why not do it right the first time, because the knock WILL return.

[Crvett69]

might not be a rod knock, about only way is to pull pan and look at the bearings. could be a piston pin or broken piston

[sbiddle]

The easy fix is to replace the motor. You can find a good used one for $300 to $400. I personally wouldn't mess with replacing the rod bearings.

[Infinitrium]

Originally Posted by sbiddle

The easy fix is to replace the motor. You can find a good used one for $300 to $400. I personally wouldn't mess with replacing the rod bearings.

That would be the best way, correct, but if the person doesn't have that kind of money they should give the rod bearings a try. A set of rod bearings are only 16 bucks from partsdinosaur.com

[rdonohoe1]

I wonder if those rod bolts are meant for a single use only - to be replaced each time they are removed? Anyone want to chime in on this???

[corning_d3]

If they are torque-to-yield bolts...

[rdonohoe1]

Yeah, that's what I meant. I couldn't find my vocabulary this morning.

[corning_d3]

And yes, most rod, main, head, or any other high stress bolt is a single use bolt, because it stretches.

EDIT: This is why using a torque wrench is so important...

[Don Alexander]

Concerning your rod knock.

First check your clearance with some plasticgage.

I have installed a new head, replaced the rod and main bearing and still have the knocking sound when the engine is cold and at low speed. The engine sounds great above 45 MPH for some reason. I am now wondering if the lifters are getting enough oil at a lower rpm. the oil pressure needs to be 39 PSI at 4,000 RPM, but in 1995 with the same engine and oil pump, the oil pressure should be 54 psi at 3,000 rpm. I wonder if this was a fix caused by a lack of oil to the lifters.

The repair manual does not say to replace the rod bolts.

Please check the clerance before putting more money into our engine.

[91Caprice9c1]

The rod studs do not need to be replaced. Neither do the head bolts or main bolts on these engines unless you see that they are stretched. None of them are 'torque-to-yield.' Torque to yield bolts are designed to stretch when torqued, and are typically given a measurement in degrees of additional rotation after torquing them down. They are used in applications where fastener stretching is not accommodated in the design and must be replaced after each use.

-MechanicMatt