72 chevy with 6.5 with a strange knock
 

i have a 72 chevy c10 i swapped a 6.5 out of a 93 gmc vandura 3500 (was told it was a 6.5 but i am questioning if its a 6.2 because of the year) runs fine with the exception of a load knocking which i cant seem to figure out

about motor
300k on odometer paperwork showing new crate motor installed at 188k
lift pump runs on igniton new with new fuel sock and sender

glow plugs are manual
injection pump is mechanical
glow plugs are newer maybe 500 miles on them
battery's are new

what i have tried / checked
- the flex plate pulled the trans and checked all the bolts and inspected for cracks ran motor without trans knock still there reinstalled trans
-harmonic balancer removed belt and inspected then ran motor without belt still have knock
-cracked each injector with each one the motor would stubble but knock stayed (still suspect as i dont know the mileage on them
-checked lift pump for operation - working fine
- replaced secondary fuel filter as it was pretty bad

from my research on here it could be injectors? or maybe a bad valve?

any help as to what to do next would be greatly appreciated i drive it to work everyday

I am new to this forum and dont know why it wouldnt let me post my whole post in the first part but hopefully this works sorry

here is a video of the knock it sounds almost like a metallic pinging in the passenger side exhaust

https://www.youtube.com/watch?v=7Hx9...ature=youtu.be

sorry for the multiple post but the motor has been driving like this with the knock for about 800 miles over the course of the last year i never heard the knock before at least not like this because it had no exhaust now that i got a exhaust on it i heard the knock and realized it didn't sound right

could be rod bearings .. lifter going bad..push rods..or rocker arms ...just a few things to check...scott:humm:

sounds like a lifter or excess rocker arm to valve clearance and it even resonates through the exhaust which could be an exhaust valve rocker arm or lifter. It could possibly be a piston pin or rod but it sounds more like valve train to me. at least I would try that first or run some risolene or lucas oil treatment through it see if it cleans up the noise.
not sure if the engine has hydraulic or solid lifters.:humm:

Nice mod I love the old 67 thru 72 chevys!

If it is a 6.5 then it is a NA 6.5,

6.5s for most part were turboed, 93 was the "crossover era" when GM stopped making 6.2s and started making the 6.5 block only until Dmax came out but a 93 early could have also been old stock 6.2 block hard to say from video if you have one of those you would have to look at the production code stamped in the valley at rear of engine under intake or stamped at rear of block flange where it mates to bell house flange.

Also hard to tell from sound on vid where noise coming from I assume this is a "new noise" that wasn't there before, or are you trying to ident, a noise that has been there since you have owned it ?

Could be valve as other indicate, also bad injector, rockers for 6.5 normally are stamped vs forged as in the early 6.2s & held in place with a nylon "button/keeper" those go bad with age you will need to remove valve cover to confirm.

Injectors for the 6.2/6.5 recommended test/change interval is 100K