90jimmydiesel
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just bought this and i cant figure out what this noise is would like to get some opinions on it before i start throwing money at it
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6.2 diesel noise
- Thread starter 90jimmydiesel
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just bought this and i cant figure out what this noise is would like to get some opinions on it before i start throwing money at it
It could be the front pulley on the harmonic balancer--some had a strange rubber cushioned arrangement that can fail and it lets the 2 pieces rattle around...
"Massboy" here had a problem woth the one on his 6.2,you might try a searching the forum for 6.2 harmonic balancer pulley posts and read them..
It could also be a broken crank,the 6.2's are noted for them breaking,and most often fail "up front" nearest the forward end...
It doesn't sound bad enough to be that,but its hard to tell listening to a video too--...
"Massboy" here had a problem woth the one on his 6.2,you might try a searching the forum for 6.2 harmonic balancer pulley posts and read them..
It could also be a broken crank,the 6.2's are noted for them breaking,and most often fail "up front" nearest the forward end...
It doesn't sound bad enough to be that,but its hard to tell listening to a video too--...
90jimmydiesel
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would the broken crank effect the power of the motor? (dumb question i know ) but i would guess that if the crank was bad i would feel that while driving? the motor has plenty of power and that noise goes away once you get going a little bit it only has that odd sound at idle
It depends--if the crank broke in a way that there is still a connection between the break,so power can be transfered,its possible it would still run fairly normal..but I doubt it would go away !..
It could be a dozen other things too--a cracked flex plate if its an automatic,sometimes a bad injector dumping too much fuel can mimic a rod knock,and the injector pump drive gears are bolted on,a bolt could have backed out--the harmonic balancer itself can separate or slip on its rubber and cause weird noises...you'd likely get a vibration if its that..
It could be a dozen other things too--a cracked flex plate if its an automatic,sometimes a bad injector dumping too much fuel can mimic a rod knock,and the injector pump drive gears are bolted on,a bolt could have backed out--the harmonic balancer itself can separate or slip on its rubber and cause weird noises...you'd likely get a vibration if its that..
90jimmydiesel
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truck doesn't have a vibration runs pretty smooth once it gets going was reading some old threads I'm going to order the pulley part #15592128 and since I'm there should i just buy the balancer also? it is an auto trans and the truck is lifted up high enough so it would be easy to take out just would like to save my self all that work from what I'm reading these pulleys seem to be a common problem and the motor has 120k on it so it wouldn't hurt to buy it. is that bolt in the injection pump easy to get to I'm new to the diesels so injection pumps are a new world for me
Sounds like something rubbing sheet metal. Doesn't sound deep enough to be a serious internal issue to me.
I once had the inspection cover tang on my SM 465 not slide into where it was supposed to. The misaligned tang was getting hit by something on the flywheel once per rev. Sounded a lot like your noise. If you can narrow down the approx location, then shut it off and have a really good look at things...you might find something stupid like I did.
Balancer failure is possible. There is an outer ring and an inner and they're supposed to be bonded with rubber. The rubber cracks and falls out over time...that's what you want to check for in that area.
I once had the inspection cover tang on my SM 465 not slide into where it was supposed to. The misaligned tang was getting hit by something on the flywheel once per rev. Sounded a lot like your noise. If you can narrow down the approx location, then shut it off and have a really good look at things...you might find something stupid like I did.
Balancer failure is possible. There is an outer ring and an inner and they're supposed to be bonded with rubber. The rubber cracks and falls out over time...that's what you want to check for in that area.
I once bought a nice running 350 the owner said was "junk" --he was taking it out to swap in a 454 when it started making a weird hollow "thunk-thunk-thunk" sound inside the engine down low...it did sound very ominous and "expensive"..
When I crawled under the truck with it running in hopes of pinpointing the noise's location,I noticed the oil pan was pulsing in and out on the bottom some in time with each revolution,and looked stoved in a bit..evidently he either bottomed it out on something,or someone may have jacked the engine up by the pan without using a wood block--I took it off after we got the engine out and home,saw where a counterweight on the crank had been scraping the inside of the pan--and the oil pump screen was loose from the pump and mushed up a bit,but had not come completely off.....
A few more miles,it would have rubbed right though the pan--or ate the pickup screen !....I put a different good oil pan I had on it,and a new oil pump (12.99 at Autozone)--no more horrible noise!..that engine turned out to be one of the best ones I had too..
When I crawled under the truck with it running in hopes of pinpointing the noise's location,I noticed the oil pan was pulsing in and out on the bottom some in time with each revolution,and looked stoved in a bit..evidently he either bottomed it out on something,or someone may have jacked the engine up by the pan without using a wood block--I took it off after we got the engine out and home,saw where a counterweight on the crank had been scraping the inside of the pan--and the oil pump screen was loose from the pump and mushed up a bit,but had not come completely off.....
A few more miles,it would have rubbed right though the pan--or ate the pickup screen !....I put a different good oil pan I had on it,and a new oil pump (12.99 at Autozone)--no more horrible noise!..that engine turned out to be one of the best ones I had too..
Could be alternator or ps pump??
Can the crank be broken if the front pulley is spinning normally?
It does kinda sound like a balancer issue, and that's one noise that does disappear away from idle. But it's still vague enough that you could have many things going on. Use your ear to pinpoint the exact location of the sound, that will help with the diagnosis.
And welcome to CK5.
And yes, do replace the balancer if you're redoing the pulley. Balancers are a common wear point on these engines, and cranks can fail if they are ignored.
