Rebuilt in 2012, approx 500mi on rebuild. Mostly stock rebuild with 440source heads, 60303 Voodoo cam, stock rockers-intake-exhaust manifolds. Started up this morning and heard what sounds like a rod knock at idle that goes away with rpm. Link to youtube vid below, initially at idle, then rpm, then back to idle.
Haven't done any testing as yet, thought I'd wait for the experts to weigh in.
I would suggest you hit the parts store for a cheap mechanics stethoscope and see what you can hear. A rod knock should have gotten louder and more rapid with the RPM change.
I'd check the converter bolts. If it was knocking that bad internally it would have lost some oil pressure. Cut the filter open and have look before you run it again. Doug
IIRC, a rod knock should "peak" with no load, just after bumping the rpm. Gonna put it up on the lift, check the converter bolts and underneath. Hoping its just a rattle.
Too sporadic, Could be rockers hitting the valve covers, Flex plate / converter bolts or a multitude of other things. Silly question, is the timing to far advanced ???
Agree it doesn't sound like a rod knock. As said, check the external items like the flexplate and converter as well as the damper and pulleys. Once you eliminate the external items, you may have to go inside and look for something like a broken crank.
Too irregular to be a rod knock. Could be converter bolts I suppose. Actually sounds more like an engine external issue like exhaust pipe slapping against chassis.
Just saying from irregularity and that only is apparent at low rpm when engine bouncing about on its rubber mounts.
Go under car while engine is running. Place a stethoscope on pan and listen for something rattling about in it.
Oil pressure all ok? How does oil on dipstick appear,,,no shiny specks?
Did I miss if automatic or stick. If stick, push in clutch,,,,any change.
I like early statement on pulleys or belts or dampener.
Good news. Loose flexplate bolts, all 4. Thx to everyone who responded. Had to move the RR yesterday after taking the video in the orig post. The "clanking" was 10 times worse than on the video.
Drained the oil (due anyway) and it was clear. Cut the oil filter in half, nothing. Tightened the flexplate bolts, new oil/filter, started right up. Only thing I could hear was the lope of the Lunati 60303
Did you use loctite on the converter bolts? I would. Spend some time and snug all your other bolts and nuts up when its cold. You may have to snug some more than once between heat cycles for the first few thousand miles.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
Re: 440 rod knock?
[Re: dvw]
#2040322 03/28/1610:44 AM03/28/1610:44 AM
I'd check the converter bolts. If it was knocking that bad internally it would have lost some oil pressure. Cut the filter open and have look before you run it again. Doug
Check the convert bolts, Do you have a magnetic drain plug? If so plug it and look at it.. if it looks like "beaker" from the Muppets you have a problem. AMHIK. You can also pull the dip stick and hold it up to a bright light, if it looks like a glitter stick you may have an issue. I when I spun an bearing in the 1st 440 in this car it still had good oil pressure.