Engine noise

[Garys1969RR]

Trying to diagnose a noise in a 451 that came in a 1965 Belvedere. Sounds like metal hitting metal. Sound is erratic, not a steady beat to it. Gets worse when you rev it up. With a piece of 3/8 tubing held against my ear, and the other end held near the oil pan, the sound is loudest. Oil pressure is good @ 60 PSI, but drops some when engine warms up. This has a remote oil filter on it, so prob a delay in building oil pressure each time its started. Looks like an engine removal/disassembly is in store for us. Just wanted to know if anyone has heard this type of noise before. I thought a rod knock would be a regular sound, not erratic. Could a bad main bearing cause this type of irregular sound? Need to know what part of motor to focus on. Thanks.

 

[sleepar]

Spun bearing... hard to tell with out looking in side but if it's deep it's that or the pump is 9/10ths shot.

 

[Garys1969RR]

Spun bearing... hard to tell with out looking in side but if it's deep it's that or the pump is 9/10ths shot.

Thats what I was suspecting. Rod Bearing. Seems to be getting louder with time.

- - - Updated - - -

It has all kinds of hi po parts, Perf RPM heads, hi stall T/C, manual shift valve body, headers etc. Must have been put together poorly and run hard.

 

[sleepar]

Not necessarily could be defective parts but sounds like you're on it.

 

[Garys1969RR]

I don't like this remote mount oil filter. Looks like there would be a delay on start up for the oil to go thru the lines, thru the filter, and back to the engine. Anyone need one?

- - - Updated - - -

It's mounted about intake manifold height, so I suppose the oil drains out of it when the engine isn't running.

 

[Sixpactogo]

One thing you may want to check before tearing things apart is if you have a manual fuel pump, you could have a weak spring on the pump arm. I had one that sounded like what I thought was something deep and low in the engine. It ended up being the rod that runs off of the cam and operates the fuel pump was not getting enough pressure to hold it tight against the cam lobe. It was intermittant like yours and didn't do it at an idle or when under load. Just at a cruise speed. Hopefully that is your problem as it is an easy fix by replacing the fuel pump. Of course we are not that lucky most of the time.

 

[wvmarv]

First thing I would do is drain the oil and see how much metal if any is in it.

 

[Garys1969RR]

First thing I would do is drain the oil and see how much metal if any is in it.

Yes that will be the next step, pull the oil filter, and drain some oil out of the pan. Looking for ground up metal particles. (Ugggg!) Possibly cam flattening or a bad rod bearing.

- - - Updated - - -

There is no mech pump on this one. Only the elec one by the tank.

 

[383man]

If its a spun rod bearing that sound is usually a deep strong knock that gets loader as you rev it up. Try shorting the cylinders or pulling plug wires one at a time and see if any make the noise change as many times a rod bearing noise will change when you take the fire away from the cyl so it does not fire. If it does change then you know its in that cylinders rod or piston pin. Just something to try. If its a main bearing it will be more of a deep low tone thud. Let us know if pulling plug wires makes a difference ? Ron

 

[nm9stheham]

A cracked crank will make an erractic knock sound too.

Stir a clean magnet around in the oil as part of your checks for metal.

 

[Garys1969RR]

I wonder if a cracked or damaged harmonic balancer would cause the noise?

- - - Updated - - -

I will try the pulling the plug wires trick this weekend.

 

[Garys1969RR]

Ok got this prob fixed! Flex plate to T/C bolts had backed out a turn or so. Enough to hit the block and cause a horrible racket! Ha Ha. This happened on another trans I had awhile back. Although I didn't assemble this one, from now on I'm using loc tite! They are the smaller size bolts. I sure do like the larger Hemi-size bolts I have on my other T/C.

 

[miller]

Man, did you luck out! Good show.