Engine is a "basket case" build, 428+060. Slightly used pistons, new rings, hand hone. Compression and oil pressure good. Heads, cam&lifters&rockers have all run before on other engines.
Never heard this noise before. Sure sounds like it's coming from the front - sounds like left front in partcular but cant guarantee that the way things echo.
I heard the banging noise in the video and figured ok, fuel pump.
So yanked it out, just running on the gas in the carb.
Ok, its the water pump. Pulled the belt, so now no fan, water pump, or alternator are turning.
Ok, a squirrel got in there and stashed a rock under the front cover.
Pulled front cover, nothing loose, nothing hitting, not scratches or squirrel dung or rocks inside.
Next pulled both valve covers, put hand on each rocker 1 at a time to feel for any noisy culprits tho it did not sound like the right spot. All 16 rockers behaving, no noise or looseness felt in any of em while running.
Maybe the fat new oil pump shaft is hitting. Swap in an old used oil pump and factory shaft.
Ok now we are down to spending gasket money. Pull left side head, expected to see a cylinder wall all scored up and a loose bolt banging around in there. Nope, clean as a whistle.
Exhaust donut was pretty ratty, could be leaking, but I've heard lost of exhaust leaks, this doesnt sound like one, too much "tinny" sound. SURE sounds like an echo under the front cover. Maybe the squirrel stashed his rock in there again.
Cant figure it out, looking for ideas.
Hope the YouTube comes though ok -
thanks for any ideas
This message has been edited by werbyford on Aug 18, 2012 1:59 PM
Pulled the dipstick and ran it, same noise.
Buddy once had rods hitting his windage tray, it kinda sounds like that but nothing hitting or even close under there. Pan has the stock cj-style flat baffle and vertical fin but those look to be miles (ok centimeters) from touching anything.
Balancer looks clear, no paint scraping off of it, ditto flywheel, I just have an MX bellhousing on it so I can reach in there (not when it's running!!) and feel, nothing touching but it REALLY sounds up front anyway.
I'm re-checking all these things of course just in case this is all taking place in a wormhole / alternate universe but just out of new ideas.
Werby, that sounds just like a 383 Chevy I did in a 98 Silverado. It had a sort of windage tray in it that didn't quite clear one set of rods with the 400 crank in it. That noise sounds crank speed to me as best I can tell from your video. You might try turning the engine by hand with the plugs out and see if you can feel anything.
Re: Need help with Mystery Noise in fresh running motor
August 18 2012, 2:04 PM
Have ya tried The Back yard Stephopscope? Long Screw Driver Handle to the Ear?
I chased a Fuel Pump once and it was Cam Bearings. I agree it sounds too fast for that. My 428 only rapped under hard throttle, until the Cam broke! There was hardly enough bearing left to drive out.
I did change the cam bearings in this beast, all looked fine w/cam spinning free when done.
But who knows - would cam bearings make that kind of crazy banging noise?
Well, one of the next steps is to swap the chain&gears for an old used set, maybe I will pull the cam while I'm in there and have a look at the bearings too. I've already had the oil pan off&on 4 or 5 times or 6 maybe.
It's awfully rapid for idle speed, are there witness marks on the timing cover? Cam chain flap? Does it occur when you turn the engine over by hand? Have you tried disconnecting spark plugs on the running engine to see if a down cylinder quiets it (pull a wire, listen, replace)?
1964 Galaxie 500, 390, Toploader, 3.50 9 inch
1967 F100 Stepside, 240 I-6, 3.03, 4.11 9 inch
I only let it run a few seconds cuz of the noise and no water pump so it's not warm enough to idle down steady.
I think I will swap in another distributor too just to eliminate that, tho this one spins over fine, no noises turning it by hand. Noise sounds way too strong for rotor hitting cap anyway but I'm down to swapping parts out 1 by 1.
Did you try pulling wires one at a time to see if problem was cylinder related? Also, althought I have ever seen it on FEs., is the side of the rod bolt hitting something? I has a six banger Chevy we did a cheapy overhaul on that had a knock in it caused by a rod out of alignment. A aligment fixture,a vise and a pry bar solved that problem. Hope this helps.
It sure sounds to me like noises that will come from a problem in the flywheel/converter, starter, blockplate area. I had a torque converter that sounded very much like that, some years ago. Sure hope you find it. RonW
This message has been edited by reman on Aug 18, 2012 4:27 PM
inspection hole for the clutch caused a very similar noise on a "other brand" for me before. Spent all day tearing thru that field, thought we broke our play toy. Yanked it out of there and tried the next day to kill that truck. Hope it's a simple fix. Later, Travis
X2 on the cam timing gear hitting on the cam retaining bolts, i had a brand new comp cam gear set that wouldnt clear the cam retainer bolts, i switched over to a cloyes and it cleared with plenty room.
yup, on my 428 i even ran it without the timing cover. had rags on everything to keep the mess down to a minimum. mine turned out to be 2 bad wrispin bushings that the machineshop neglected to replace......
That's 1 reason i pulled the left side head (sound seems from left side)
I figured I'd find scored up cylinder wall[s] and rubble but nope, clean as a whistle. I assembled pistons myself, all seemed tite so hopefully they stay together. Sound seems too fast for a single cylinder anyway.
Does the Camshaft timming gear require a spacer between it and the cam?
Some gears come with it as part of the gear and on some you have to add the spacer.
As the cam get old the spacer looks like part of the cam,new cams do not come with the spacer.
I saw this break two lifters and destroy the camshaft.