Trying to Diagnose Knocking Sound

[soth122003]

Hey Joe,

 

Since the radiator is out and the pulley is off do what I did. I duct taped a garden hose to the input for the water pump, Turn it on low to medium and let the water come out the thermostat housing area. That way you can run it for a couple of minutes with out overheating your engine. the flow of water will keep the engine cool enough for checking the knock.

 

Joe

[SQ4MN]

From everything you've said my guess is its a rod knock. Knock increases as oil gets warm, increases or decreases depending on rpm's,  can hear it loudest thru breather tube. These are all things rod knocks do but the really strange thing you describe is the noise that started all this, that makes me think it might be something else all together as that noise would not precede a rod bearing going bad.

[DJ194950]

Joe, been following this post from the start as I too have a slight tick that getstoo much louder (for my liken!) when warm. Done Most of the tests suggested and used a stethoscope as you have. Still no answer. Even pulled pan and checked each bearing on the crank one at a time, no real problems. I did check all the pistons and rod end bushings at the rebuild (many good used parts with all new rod bearings (plasticgaged)  and  (rechecked in the car after 1000 miles when noise first showed up) and new rings. Like new timing chain and gears.

 

Still have to check the fuel pump as suggested.

 

I'm thinking try the suggestions offered as the car sits. see if any thing. if not drop the pan and check the Crank bearings one at a time with plasticgage. If Ok remove timing chain cover and inspect. Look to see if the one screw from inside of plate behind the cover to block has come loose and rubbing the chain.(screeching noise?)

 

Will continue to watch all posts for your problem that may also lead me to mine.

[james curl]

A loose wrist pin bushing is hard to find and sounds much like a loose tappet.  With the oil pan off you have to bring each cylinder to TDC and rock back and forth enough to change directions at the top.  Using a flash light look at the gap in  between the rod and piston, watch for any movement.  If you get any movement the bushing is worn and will only get worse in time.

[Joe Flanagan]

From everything you've said my guess is its a rod knock. Knock increases as oil gets warm, increases or decreases depending on rpm's,  can hear it loudest thru breather tube. These are all things rod knocks do but the really strange thing you describe is the noise that started all this, that makes me think it might be something else all together as that noise would not precede a rod bearing going bad.

That's the really interesting thing about all this. The noise was sudden and really strange and it didn't happen until I engaged the clutch. It was like a grind and a drag and as I stepped on the brake, a tick-tick-tick sound. It was happening as I backed up a few feet and then slowly stopped as I stepped on the brake. Since then, there's been this noise. It seems like as soon as the clutch engaged, something let go, something that spins with the engine. I was thinking that maybe something around the flywheel/pressure plate has gone wrong. If that were the case, wouldn't the sound be transmitted through the crankshaft and to the part of the timing chain cover where the crankshaft passes through? That's where I heard it the loudest. 

Anyway, that's all speculation at this point. I'm going to try to do this in an orderly fashion. Next up is running the engine without the pulley installed. I'll report back on that. After that is examining the fuel pump. I also want to see if I can figure out if the noise is at cam or crank speed. Since the noise has gotten much more regular and pronounced, I will also try pulling the plug wires one by one to see if that isolates the sound. 

[Plymouthy Adams]

a guy on another forum had a noise in his engine that he was having trouble with...after a bit he comes on line and makes a single post...

 

NOISE IS GONE...

 

nothing else...when pressed for the details it was learned he sold the car.....as it...thus the noise was truly gone...

[Lloyd]

It was like a grind and a drag and as I stepped on the brake, a tick-tick-tick sound. It was happening as I backed up a few feet and then slowly stopped as I stepped on the brake

 

 

I think its in the bell housing. I would stop with everything else and peek thru the inspection cover at the flywheel. A bearing might make a grinding noise if it was out of oil then it would turn into a knock real soon. But why did it start and continue when you dropped the clutch and was moving then when you stopped it was making a tick sound? What has that got to do with the crankshaft?

[John Reddie]

a guy on another forum had a noise in his engine that he was having trouble with...after a bit he comes on line and makes a single post...

 

NOISE IS GONE...

 

nothing else...when pressed for the details it was learned he sold the car.....as it...thus the noise was truly gone...

NOISE IS GONE - CAR SOLD. That is hilarious.

John R

[Jeff Balazs]

Joe;

I wish you all the best with this. Noises like this can be extremely hard to track down. They can sound like they are coming from one area and end up coming from the opposite end.

A clue might be found in your statement about it all starting when you reversed. Any chance it is coming from the clutch itself.....or the throwout bearing?

That grinding sound you heard as you reversed doesn't seem like something that I would associated with the engine itself.

 

Jeff

Edited October 8, 2014 by Jeff Balazs

[Plymouthy Adams]

actually the rear bearing journal is the very controller for end play in the crank shaft..standard shift cars are a bit rough on this bearing...as this is also second go-around on the build...was the surface of the crank for this actually checked, mic'ed and known to be true and smooth so not to have premature wear...not trying to throw negs in here but a worn thrust bearing does provide engine knock..albeit most  of the time it is on when you operate the clutch..check end play of your crank for proper specification while you are at it...pulley can be off...check at the hub as it sits now...I do not suspect this a real problem if machine work was done to specs but NEVER just arbitrarily rule something as good without a check..

 

as you provide data on the earlier build and stuff done/failures so will the possibilities increase in likelihood..

Edited October 8, 2014 by Plymouthy Adams

[Joe Flanagan]

Could be clutch related. I hope so. I will investigate it and let you know what I find. Thanks to everyone who has offered advice, etc. 

[Joe Flanagan]

actually the rear bearing journal is the very controller for end play in the crank shaft..standard shift cars are a bit rough on this bearing...as this is also second go-around on the build...was the surface of the crank for this actually checked, mic'ed and known to be true and smooth so not to have premature wear...not trying to throw negs in here but a worn thrust bearing does provide engine knock..albeit most  of the time it is on when you operate the clutch..check end play of your crank for proper specification while you are at it...pulley can be off...check at the hub as it sits now...I do not suspect this a real problem if machine work was done to specs but NEVER just arbitrarily rule something as good without a check..

 

as you provide data on the earlier build and stuff done/failures so will the possibilities increase in likelihood..

Tim,

On the second rebuild, the machinist honed and polished the scratches off the crank. I believe he miked everything, too. It was some years ago. I checked the bearing clearance with plastigauge when I put everything back together. But I would like to check the crank end play all the same. When you say, "Most of the time it is on when you operate the clutch," do you mean most of the time it will knock when you operate the clutch? Not so much when your foot is off the clutch? As you know, this knock is constant.

When I do check the end play, I'm assuming it will be with the pan off and using a pry bar to see how far I can move the crank back and forth along the length of the engine. Is this correct?

[Plymouthy Adams]

Joe Flanagan, on 08 Oct 2014 - 11:01 AM, said:Joe Flanagan, on 08 Oct 2014 - 11:01 AM, said:

Tim,

On the second rebuild, the machinist honed and polished the scratches off the crank. I believe he miked everything, too. It was some years ago. I checked the bearing clearance with plastigauge when I put everything back together. But I would like to check the crank end play all the same. When you say, "Most of the time it is on when you operate the clutch," do you mean most of the time it will knock when you operate the clutch? Not so much when your foot is off the clutch? As you know, this knock is constant.

When I do check the end play, I'm assuming it will be with the pan off and using a pry bar to see how far I can move the crank back and forth along the length of the engine. Is this correct?

I believe I read the above to indicate that when reversing and clutching you heard some strange noise and scraping sounds...just a FYI here Joe and now is the time to make a quick end play check....

 

as you posted in part......

 

That's the really interesting thing about all this. The noise was sudden and really strange and it didn't happen until I engaged the clutch. It was like a grind and a drag and as I stepped on the brake, a tick-tick-tick sound. It was happening as I backed up a few feet and then slowly stopped as I stepped on the brake. Since then, there's been this noise

Edited October 8, 2014 by Plymouthy Adams

[suntennis]

Had a noise problem following engine rebuild that came from the front of the engine. Turned out the front crank seal protruded into the timing chain area more than the original and was making contact with something. When discovered, a small amount of the seal was removed and problem solved.

[Don Coatney]

NOISE IS GONE - CAR SOLD. That is hilarious.

John R

Makes me wonder if the new owner paid extra for the noise?

[Jeff Balazs]

Joe;

I have a bit of end play in my crank. No knock but a faint squeal or rubbing sound until it gets up to full operating temperature. If I step on the clutch when it is still cold it goes away. I did not use a speedy sleeve when I replaced the front seal so I am fairly certain the noise comes from the end play and the seal against the worn surface of the pulley hub. I will continue to monitor it closely until such time as the engine itself starts making noise. I think it will be OK for a while. And it does go away once warm.

 

When I first started hearing it I was pretty certain it was coming from the clutch and /or the fluid drive. Took me a while to pin point it......at the opposite end of the engine. I would have sworn it was the clutch. This was one that the stethoscope was not as effective a tool as a piece of hose. Once I was pretty certain I found it I proved it with a drop of oil in the right spot. The oil would make it go away for a couple of minutes.

 

Jeff

[Merle Coggins]

When I do check the end play, I'm assuming it will be with the pan off and using a pry bar to see how far I can move the crank back and forth along the length of the engine. Is this correct?

 

No need to pull the pan, Joe. You'll need a dial indicator or something to measure the movement. Push the crank rearward as much as possible. Pry between the block and flywheel, or from the front prying back against a cross member or something. The zero your measuring device and pry forward to see how much it moves. I've used the depth gauge on a dial or digital caliper for things like this too, when my dial indicator wasn't readily available.

 

Merle

[Joe Flanagan]

I just ran the engine for 20 seconds without the pulley and there was no noise. I did this twice with the same result. 

[blueskies]

Joe-  I feel your pain...  Trying to find the noise in my flatty was a total pain.  I'm convinced that my wrist pin bushing went south due to running the engine for thousands of miles with too much advance (Langdon HEI...)

 

I hope your noise was just the pulley, and a simple fix.

 

Pete

[deathbound]

I just ran the engine for 20 seconds without the pulley and there was no noise. I did this twice with the same result.

[Reg Evans]

Good news !  Maybe try this next..........fill the head as full as you can get it and do a short run while using the clutch and backing up a little.

[casper50]

I hope you've found the culprit.  Easy fix and cheap too.

[Lloyd]

Congratulations! Glad to hear it isn't anything in the engine. Sometimes the most obvious is the hardest to see.

[Joe Flanagan]

Subsequent tests of 30 and 40 seconds also did not produce the noise. 

[Don Coatney]

Suggest when you replace the repaired pulley you also install a new belt.