VegasJen

my fresh motor has a knocking sound from deep within the bowels. i really doubt it's a rod knock but that sure is what it sounds like. i pulled the wire off each plug while at idle and the knock never went away, which should mean no spun bearing, but i digress.
i'm thinking that my crank scraper shifted when i put my pan on and that's the source of the knock. if so, i'll let it go.
anybody else have some slick shadetree check for a rod knock?

TimAT

I can't think of any other way to check. As much as it hurts, if it quacks like a duck....

Me, I'd have to drop the pan and have a look see.

BTW-- How's the ankle?

Durango_Boy

Have you drained the oil? Strain the oil with a coffee filter, and check for metal. If it's clean then you probably don't have any wearing soft metal parts.

Pull the pan after the drain, and inspect the scraper for any contact damage.

fotyfobravo

Replace the fuel pump rod ....

I had a fresh SB that sounded like a rod or a wrist pin slamming against something ...

I isolated the knock as close as possible by "listening" through a piece of heater hose. I swapped out the pump rod ... smooth and silent for 5 years now.

Good Luck !

ghoastrider1

This didnt work for me.Tried it once back in the early 70s.The oil was to thick or the filter not poreous enough. Stinking oil stayed put after just a little bit drained through.

SanDiegoPaul

That's as good a suggestion as any. I've seen it too back in my tech years. The pump rod *can* sound just like a rod knock.

Also by the way, can the harmonic balancer when it comes loose or apart. Get down there and check it too.

Durango_Boy

Yeah, I guess that does depend a lot on the weight and viscosity of the oil. Thinner oils and synthetic oils will filter better than thick dino oil.

SanDiegoPaul

Sure it does. Another thing to look at would be/could be sending the oil out for a sampling. Do a Google search for the service .... what they will need is an ounce of the used oil and they will check it for metals suspended within it. Kinda like a **** test for your motor :-)

That service may even be available where he's located. Here in San Diego we used to have them sent to LA but there may even be a place that does it here in town now, for all I know.

Vette Crazzy

vc

coinwasher

I agree pulling the pan on a C3 is much easier than it seems. Remove the two bolts where the steering bolts to the frame on the passengetr side with the car jacked up and the front wheels will point at each other, the steering stuff just hangs out of the way. Use one of those new one piece blue pan gaskets and it really goes well. I have swapped out an oil pump before in an hour and a half.

TimAT

If the coffee filter is too small, how about swiping a pair of pantyhose from your spouse? Use them to strain the oil. May not catch the small stuff, but it will get the chunks.

And I, too have heard fuel pumps knock like a rod. One was so bad the knock sensor "heard" it and retarded the timing so far it wouldn't hardly run. Good thought.

jerrylee

[QUOTE=SanDiegoPaul;1560022796]Sure it does. Another thing to look at would be/could be sending the oil out for a sampling. Do a Google search for the service .... what they will need is an ounce of the used oil and they will check it for metals suspended within it. Kinda like a **** test for your motor :-)
Try [blackstone-labs.com]....They send u a free sample bottle n you just send 20 bucks along with the oil sample
n they will anylize your oil 4 you.....Jerrylee///

saudivette

If you're stuck for what to search for, try Spectrometric Oil Analysis Testing

They burn your oil sample and from the colours in the light spectrum that are given off, they can determine what metals and how many parts per million of it are suspended in the oil

dgruenke

Another possibility is a loose flywheel bolt or a cracked flywheel.

VegasJen

i'm not going to base any decision on what i find in the pan. the motor doesn't even have 50 miles on it yet, there will be stuff in there.
i'm thinking you guys might be right on the fuel pump rod. i didn't think about it when i put everything together but i put a standard steel (lightweight) pump rod on a roller cam. this is my first roller motor so i'm thinking i probably shouldn't have done that. steel on steel not generally good.

TimAT

AH HA! I bet you need a different push rod. Drop the fuel pump and start it up. There'll be enogh gas in the carb to prove one way or the other..

Good Luck

slowride262

I had a cracked fly wheel that sounded just like a bad bearing in a 72 Chevelle.But then again I also had a S-10 that had the wrong fuel pump in it and the rod made a Sh(t load of noise to.

jimvette999

FWIW....I rebuilt an engine in a Chevy pickup once, opted for the pretty Mr. Gasket chrome pan. Fired it up and had a light knocking sound. Turned out to be the pan. It was not a stroker motor.