Engine knocking need help identifing

[Jalvarez]

thanks esker:
checked all coils and new spark plugs installed. spark on all 4 wires ok as I already checked.he sopark did jump to the head when the wire was closeer to it. But we wire conected spark is where it should be. Yes the noise will almost dissappear from time to time, when the idle speed is very low.
I do have mechanics stethoscopes and the nearest I can tyell the sound is coming from the valve cover on Piston#2

 

[scdmarx]

How did the original spark plug look when you removed it? Was there a lot of carbon build up?

When I had a similar noise, it seemed to come from around the #2 cylinder also. Sure would like to know what it was.

 

[Jalvarez]

they looked clean before I removed the heads. just put new ones because I wanted to start fresh

 

[dan filipi]

What esker is saying about spark jumping inside the plug cap seems possible for a noise this loud.

Next up I would swap plug wires side to side and see if the noise moves.

P.s I don't think its oil pump related.

Just thought of something, could it be the exhaust making noise pushing thru a collapsed inner header pipe wall?

 

[medcoman]

Just a shot in the dark, but check spark coming out of the coils. It almost sounds like spark jumping. Also did you check the timing belt adjusters?.

 

[toytender01]

OK!!! way out, But has anyone checkew with honda to see if they are missing a mechanic with a hammer ???? :smilie_happy: :smilie_happy: Sorry coulden't let that slip buy :Egyptian: :sensored:

 

[Jalvarez]

I swaped plug wires with anoth set I had a noise continues in the same area. It still sounds live a valve hitting. The sound goes away intermitently at very low RPMS and when I accelerate it going in line with a valve speed.

I checked exhaust and all looked and sounded OK in the exhuast

 

[Jalvarez]

Just posted anoth video which will again give you the noise and best describes the noise at varying RPMs

https://youtu.be/wplv7tm_vQU

 

[dan filipi]

The only thing I can think of now is valve hitting but I do have my doubts.

There are 2 marks on the cam pulleys.....Not all that hard to mistake them and be a tooth or 2 off.
(Just throwing it out there)

 

[Jalvarez]

Dan: I also sent a video verifying the timing marks and settings.
Before I pull the head off with another..... do you recommend I change the rockers from another head?
Do you suggest I retard of forward on notch on the cam? If so which one and which way?

 

[mcgovern61]

The only thing I can think of now is valve hitting but I do have my doubts.

There are 2 marks on the cam pulleys.....Not all that hard to mistake them and be a tooth or 2 off.
(Just throwing it out there)

Looking at his cam video, he is right on the correct marks for the '83 cam pulleys.

 

[mcgovern61]

Before I pull the head off with another..... do you recommend I change the rockers from another head?
Do you suggest I retard of forward on notch on the cam? If so which one and which way?

I would not move the belts one tooth either way at this point, you are right on your pulley marks.

Without knowing if a rocker is bad or incorrect (which from the videos does not seem likely IMHO) changing them may not make any difference.

I forwarded your video to a engineer/mechanic friend of mine and he is under the opinion that it might be a rod bearing based on how the sound is consistent with piston speed and did change after the plug wire was pulled (effectively taking the load off the bearing). No easy way to tell and I am not sure I am in complete agreement.

Pulling the head may reveal the issue. If you find a shiney spot on valve.....it's hitting. He suggested that if your head is off, bring the piston to TDC and then slowly start to rotate it away from TDC (just enough to make the rod change direction. Them push on the piston crown and see if the piston has play in it towards the bearing. Not real accurate of a test, but at least something to try before pulling the engine.

 

[AApple]

After hearing the last posted vid, that is definitely something hitting something it shouldn't be. I wonder if a rod bolt hasn't backed off enough to be slapping on the cyl. case?
:headscratch:

 

[dan filipi]

Dan: I also sent a video verifying the timing marks and settings.
Before I pull the head off with another..... do you recommend I change the rockers from another head?
Do you suggest I retard of forward on notch on the cam? If so which one and which way?

There's nothing that jumps itself out at this point telling us what it is.

If the right side is quiet I might consider swapping right and left rockers and see if the noise moves and while the rockers are off take a good look at the springs to verify none are broken and are seating properly, same with the keepers.

 

[joedrum]

hmmmmm i still cant hear it but ....at this point im taking your word its timed and making noise ...id take the rockers off the cylinder you think is making the noise take the plug out of there to ....now the valves sould stay shut and not build up pressure and start it and see if it makes noise ...hopfuly not ...as this would indicate lower problem or something else other than valves

 

[Jalvarez]

Joedrum: I will remove rockers from pistin #2 where I beive the problem is as you suggest to see if it is the valves.

Thanks

 

[dan filipi]

Excellent idea Joe since that should isolate top and bottom end as a source of the noise.

 

[Jalvarez]

Next I will switch rockers from piston #4 and see if the noise continues. I posted video of results of rockers removed from Piston #@ where I thought the noise was loudest

https://youtu.be/v48mrkWw5YQ

 

[dan filipi]

Let's try to further isolate it since the noise has reduced at a lower rpm.
I'd leave the setup just the way it is in that last video but try it with the plugs removed.

 

[Jalvarez]

posted most recent 83 Knocking with no rockers or spark plug on cyl#2. Noise not present

https://youtu.be/jna0ZwEJjak