knock in engine

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wont be until Tuesday (heading out of town as soon as the wifey gets home)
but ill get it up
 
got a chance to take a video today
the knock is pretty clear once it gets a few more revs on is


[ame="https://www.youtube.com/watch?v=HAPH8xQPzCY&feature=youtu.be"]20150706 181443 - YouTube[/ame]


one more thing I noticed is that when I rev it the oil pressure drops about 10 PSI
(I did this with the engine cold)
it was running at about 60 PSI, and when I revved it it dropped to 50

could it be the oil pump bolts are coming loose?

the oil pump is new and was torqued to spec (cant remember what it was, 35 pounds?)
 
diymirage said:
think I got it fixed (the link, not the engine)
Click to expand...


The video is now working in the thread.


I would pull the oil pan and check the rod and main caps. That sounds like a lower end knock to me. I wouldn't take any chances on running it and breaking something without an inspection.

Or maybe the crank hitting on a windage tray or something.

Flex plate or torque converter bolts loose...


Just throwing out some ideas...
 
the video plays in the post on my screen ?

there is no windage tray there so that's not knocking
I checked the torque converter bolts last week, they are all tight
(obviously cant get to the flex plate with the engine and tranny in)

im afraid that pan will indeed need to come off

any thoughts on my hopes it might be the oil pump?
 
That sounds too slow for anything in the pan. It sounds more like cam speed.I wonder if the top sprocket is coming loose and the cam is walking back and forth. If it was doing that, the lifters and lobes might be clashing. And the oil holes to the top end would be moving off center, and that might explain the oil pressure shenanigans.
Check the bottom fan pulley (on the crank)first. Then pull the dizzy and attempt to pry the cam,forward and back.
I have never heard a sound like that before.
 
I would imagine if the cam is walking around I can hear it on all 8 cylinders?
this definitely seems to be coming from the back driver side of the engine, around numbers 5 and 7

it does sound like it might account for the drop in oil pressure...or would it be more likely to cause a spike?

i will add checking the fan pulley (for play i take it?) and checking the am for movement to the list
ill report back as soon as i have a chance to see what the results are
 
I suspect a main bearing going by you saying the oil pressure drops when you rev it. The crank is pushing away from the the block when you rev an engine. I had a 390 ford truck engine do that and the main bearings were shot.
 
had a water pump bearing go bad, had that funky noise , i would take the belts off just to eliminate front motor noise possibilities , good luck, hope its something easy
 
sleepyhead416 said:
Unplug 1 spark plug wire at a time and try it.
Click to expand...

What am I look on for doing that?
It still seems to be running on all 8, do you think if I pull the wire off the cylinder that is affected it will "coast along" without any racket?
 
mikec said:
had a water pump bearing go bad, had that funky noise , i would take the belts off just to eliminate front motor noise possibilities , good luck, hope its something easy
Click to expand...

I think the noise is coming from further back in the engine but I'll give that a try as well
 
If the cam sprocket is coming off, the cam will be able to slap the rear cam cover. Put a timing lite on it. If the timing is rock steady, your sprocket is fine. If its jumping around,several degrees or more, keeping time with the noise, Bingo!
 
What about crankshaft end play?

torque converter not properly installed?
 
Pull the starter off. Look at the bendix. It has a retaining ring that is notorious for coming loose and when it does, it falls into the ring gear and makes a heck of a noise.......very similar to what you have.
 
Sounds like a big end bearing failure to me. My 360 had a very similar knock, especially when you back off the throttle. I would take the sump off and check each one, I reckon that's where you will find your problem.

Regards
Anthony
 
AJ/FormS said:
If the cam sprocket is coming off, the cam will be able to slap the rear cam cover. Put a timing lite on it. If the timing is rock steady, your sprocket is fine. If its jumping around,several degrees or more, keeping time with the noise, Bingo!
Click to expand...

this sounds like an easy enough check, ill try to get my hands on a timing light and follow up on this


krazykuda said:
What about crankshaft end play?

torque converter not properly installed?
Click to expand...


I did not feel any play on the crank, I put a tire iron behind the pulley and couldn't move it

I pulled the inspection plate and checked the 4 bolts holding the converter on, they were nice and tight

RustyRatRod said:
Pull the starter off. Look at the bendix. It has a retaining ring that is notorious for coming loose and when it does, it falls into the ring gear and makes a heck of a noise.......very similar to what you have.
Click to expand...


this idea I like (not pulling the starter, with the headers that are on it, that is about the same as pulling the engine)
the starter does has a hard time engaging at times, it will whine and not crank the engine so there might be something here

doesn't explain the drop in oil pressure though
whit68 said:
Sounds like a big end bearing failure to me. My 360 had a very similar knock, especially when you back off the throttle. I would take the sump off and check each one, I reckon that's where you will find your problem.

Regards
Anthony
Click to expand...

that will be my last resort, pull the pan
 
I pulled both valve covers too make sure there is plenty of oil coming on the top end and that looks good

next ill pop the belts off and if that doesn't cure it the engine is coming out so I can inspect the starter and things on the inside
 
Snake said:
Total bummer ,I feel for ya.
Click to expand...

I was pretty bummed about it for a week or so
until I talked to the wifey along the lines off "if the crank needs to be machine I might as well just buy a stroker crank for it"
and she said "just do it right this time"

so depending on what I find today or tomorrow it will get fix or stroked

(which was a long term plan anyway but I was hoping to do it more at my leisure over a winter)
 
Lol

Smh...terrible. Good thing she doesn't know grinding a crank doesn't cost more than half what a cheap stroker crank goes for...unless you know a very cheap vendor...
 
the difference between a "stock" rebuild and a 408 is less then $1000.00 when reconditioning rods, about $1400.00 with new rods

http://www.forabodiesonly.com/mopar/showthread.php?t=320354


on a side note, does anyone know if I can unbolt my dougs headers and leave them connected to the rest of the exhaust when I pull the engine or do they need to come out the same way they went in?
 
diymirage said:
the difference between a "stock" rebuild and a 408 is less then $1000.00 when reconditioning rods, about $1400.00 with new rods

http://www.forabodiesonly.com/mopar/showthread.php?t=320354


on a side note, does anyone know if I can unbolt my dougs headers and leave them connected to the rest of the exhaust when I pull the engine or do they need to come out the same way they went in?
Click to expand...

I pulled my headers on my 68 cuda when I pulled the engine as it made more room to pull the engine. I would loosen them up and tie the left one while pulling the engine as it went through the suspension linkages...

It's easier to mount them to the head without having them attached to the rear pipes and having to fight them to align the headers on the end studs. Then attach the pipes after the headers are bolted to the heads...

But I had Hookers.... :love9:
 
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