Help I have to get to work on monday

[69GMCCustom]

Ok so I have to do something at work...lol. So I researched the sounds and it sounds kinda like this

tap 001 - YouTube

and this

Rod Knock :'( - YouTube

After I examine the bottom end I'll put it back together and try to shoot a vid. But at least I'll know its not bearings after I look at them.

[RUSHNBOBO]

Originally Posted by 71 GMCDRVR

After reading and thinking about it, it sounds exactly like mine did. It sounded like rockers it came and went for the first couple of weeks then just went downhill in a hurry. Any loss of power? Is it more of a tick? could also be a fuel knock, where is your timing set? Cheap gas? (I had all these problems when I switched motors)

Iv'e had this same type noise and it turned out to be spark "knock".........."pinging" is more of the "marbles in a can sound"........they actually have two different causes.......here's a good description of the two:

"Knocking can occur under pre-ignition due to poor quality fuel, carbon deposits, etc. or due to improper timing (advanced), The 'knock' comes from the piston being forced down on its up-stroke by the pre-ignition or the spark firing too soon, banging the piston down while it's trying to move up and against the cylinder wall, rattling the works all the way to the crank. This opposition of forces is what makes it louder and more pronounced."

"Pinging occurs from post ignition, after the piston reaches TDC and begins its down-stroke. Caused by poorly ignited fuel resulting in an extended or delayed ignition, too much fuel resulting in an extended combustion cycle or improper timing (retarded), Etc.. Basically anything that could cause an undesirable ignition after TDC."

[RUSHNBOBO]

Originally Posted by 69GMCCustom

Ok so I have to do something at work...lol. So I researched the sounds and it sounds kinda like this
After I examine the bottom end I'll put it back together and try to shoot a vid. But at least I'll know its not bearings after I look at them.

Number one sounds like a rocker nut backed off about one to two turns or a stuck lifter ....same noise, different fix.

Is the sound "rythmic" like the first example or is it more erratic or without a distinct rhythm?

[69GMCCustom]

definately rythmic. with each rotation of the engine in park, if I rev it, raising the rpm's it increases in speed with the rpm

[RUSHNBOBO]

Originally Posted by 69GMCCustom

definately rythmic. with each rotation of the engine in park, if I rev it, raising the rpm's it increases in speed with the rpm

Unfortunately that kinda eliminates spark knock....the easy one. It will be very erratic without pattern.

If it sounds like the first, even with the bad sound ...I've had rocker nuts back off ...and it sounds just like that, it may or may not also start to run rough ...do to the valve not lifting far enough. It will be pretty obvious that's it's coming from the valve cover area...and not lower on the bottom end.

Very east to check ...by removing the valve covers ...then turn the engine to the "o" tdc mark now check the rockers which are the ones with the valves closed for excessive play, they should touch the pushrods and valve stems but not wobble from side to side or up and down. Now rotate 360 degrees and check the rest.

If this isn't it ... possibilities are rod bearings....or even cracked piston skirt. The sound will be from deeper in the engine though.

Check the easy stuff first....then you can start to get worried...cause it might be expensive.....good luck

[Boog]

Have you verified the timing? How about the plug wire firing order? Crossed wires 5 & 7? Carbon buildup in the combustion chamber can cause a hard knock. You can warm the engine up and trickle some Seafoam down the carb, shut it off and let it sit for a bit to soak. Start it up and blow it out. If it's a carbon issue this will help. If not you didn't spend but a few dollars and it needed cleaning anyway.

[71 GMCDRVR]

Originally Posted by RUSHNBOBO

Iv'e had this same type noise and it turned out to be spark "knock".........."pinging" is more of the "marbles in a can sound"........they actually have two different causes.......here's a good description of the two:

"Knocking can occur under pre-ignition due to poor quality fuel, carbon deposits, etc. or due to improper timing (advanced), The 'knock' comes from the piston being forced down on its up-stroke by the pre-ignition or the spark firing too soon, banging the piston down while it's trying to move up and against the cylinder wall, rattling the works all the way to the crank. This opposition of forces is what makes it louder and more pronounced."

"Pinging occurs from post ignition, after the piston reaches TDC and begins its down-stroke. Caused by poorly ignited fuel resulting in an extended or delayed ignition, too much fuel resulting in an extended combustion cycle or improper timing (retarded), Etc.. Basically anything that could cause an undesirable ignition after TDC."

Thanks for the info....I was just throwing some issues out there. From the sound of it it sounds like rockers or lifters which from recent happenings I found out is no bueno..ended up costing me a few hundred for a new cam and lifters!!!...but once again thanks for the info brother.

[71c10bbsuper]

if you put your valve covers on backwards the rockers wiil hit the cover and sound like this ,don't ask how i know but easy to do

[69GMCCustom]

Update... The underside of my engine looks great...I guess the previous owner did rebuild it. Nothing in my oil pan or oil. No shavings on my magnet. I grabbed and shook each piston rod connection to see if I was missing berings...nope, its all tight as can be. I scoped my cylinders, the walls look smooth, nothing on top of the pistons (thank goodness I could borrow the inspection scope from work...I'll probably purchase one later tho, they are really cool, I mean Useful. lol) I rotated my engine till TDC on 1, then rotated all the way around, took almost two hours, checked each rocker for tightness. Following the info here on the forum, tightened till I couldnt rotate the push rod, then 1/4 turn while at full lift. Watched each lifter raise and fall, none looked stuck, engine rotates smoothly. Tomorrow I will start the reassemble. I forgot to check for markings on the inside of my valve covers, however I know i had them on right..I took pics before and after, and they are trimmed to clear the manifold. I will leave them off when i start it this time to ensure I have good oil flow to my heads. Thank you one an all for all your help, and I am constantly amazed at how much information there is on this forum.

[camrycurt]

Originally Posted by 69GMCCustom

Update... checked each rocker for tightness. Following the info here on the forum, tightened till I couldnt rotate the push rod, then 1/4 turn while at full lift.

I may be wrong, but I think I remember that when adjusting valves the point at which you feel the first bit of drag on the push rod is the zero point, and you tighten the additional 1/4 turn from there. By tightening them until you couldn't spin them at all, you may have gone too far.

I'm sure someone much smarter and more experienced than me can confirm this for you or not, but you might want to double check that before you fire everything back up.

[RUSHNBOBO]

Originally Posted by camrycurt

I may be wrong, but I think I remember that when adjusting valves the point at which you feel the first bit of drag on the push rod is the zero point, and you tighten the additional 1/4 turn from there. By tightening them until you couldn't spin them at all, you may have gone too far.

1/4 turn will work, I like to go 1/2 turn ....just don't go to 1 full turn this will put the lifter plunger at or very near the end of it's travel and possibly not allow the valves to close all the way, this is bad.

Here's a great link with diagrams with circles, arrows and charts.

http://www.centuryperformance.com/ad...h-spg-149.html

[71 GMCDRVR]

I like to set the valves with the engine running. Take it to zero lash then an additional 1/4 or 1/2 turn. But if you over tighten it will hold the valves open and they won't seat properly. Your truck will not run smoothly. It is a little messy but I think it's the best way to set valves!

[69GMCCustom]

ok so the engine is back together...i have oil pressure, left the valve cover off drivers side to check. engine still knocks, loud even when hood closed. I have no idea any other ideas gentlemen? I'm shooting for next monday now lol.

[haysonj]

Originally Posted by 69GMCCustom

ok so the engine is back together...i have oil pressure, left the valve cover off drivers side to check. engine still knocks, loud even when hood closed. I have no idea any other ideas gentlemen? I'm shooting for next monday now lol.

If the sound lessens as the motor warms up you may have pistons that are to loose in the bore. I have one in my 383 that sounds like the first vid when cold but mellows out as the piston warms up.

[richards72chevy]

My 69 impala made the same noise in the videos you posted.The noise was worse towards the bottom of the motor.It ended up being the pulley that is bolted to the harmonic dampener had cracked.

[Stocker]

Did you ever check for loose torque converter bolts or a cracked (or loose) flex plate?

[69GMCCustom]

richards- I removed the wp pulley and fan when i set the engine to tdc. It looks ok...

Stocker- No unfortunately I cannot remove my tranny here in this rental house, the driveway is about a 10 degree angle. I did remove the cover and look in there as best i could with a light, but I know that will not enable me to see much.

[69GMCCustom]

I did do this....

How To Properly Diagnose A Broken Flywheel 1 of 2...

lol. but i think that might be worst case senario

[OJ1988]

Check those converter bolts. Had this happen on a friends car, after we freshened up the motor, got it together, and it made that sound. I thought we had wiped out a lobe on the new lat tappet cam, as that is easy to do thanks to todays oil, turned out to be loosed converter bolts. You have to tighten them with the trans installed, so no need to drop it.

[OJ1988]

Just to verify, it ran fine before you swaped intake and carb? No other items were swapped at this time?

[69GMCCustom]

before I swapped intake and carb it ran great, then started idling rough. I checked and the carb had sprung a leak, so i replaced the carb and manifold...if youpr purchasing a new carb, might as well be a 4 brl instead of 2. Than I got the knock.

[OJ1988]

Have you checked those converter bolts yet?

[OJ1988]

Seems odd it happened after only a carb and intake swap. What intake did you go with?

Perhaps it was not drilled for the dist properly, and causing the distributer to be in a bind, or out of alignment?

[69GMCCustom]

Edelbrock RPM air gap. with and Edelbrock 600 CFM Carb. I never thought about the dizzy not setting straight.

[OJ1988]

RPM air gap is a good intake.

Just trying to narrow it down for ya. I would still check the converter bolts. Like I said, had that very issue.