Jartanyon

Hi All - rebuilt my engine and broke in the cam last week. Noticed this week that there is a constant knocking noise (7 seconds into video). At first, I thought it was my exhaust banging on the frame since it seems to only be on one side, but it is coming from the engine bay. Any ideas? There is also a high pitch click noise (30 seconds in) that I believe is valve train. Any help would be appreciated.

https://vimeo.com/95975498
https://vimeo.com/96229784
Password is knock

CaseyJones

Check to make sure the balancer is installed properly. Mine went out and I thought the power steering pump was making a noise until I removed the belts and saw that the balancer could be moved by hand. It was wobbling on the crank snout and the key had broken. Not hard to fix but it could have been a disaster.

Indiancreek

Do your heads still have pressed in rocker studs?

forman

how long was the motor broken in for ,, what kind of parts did you use on the top end , and what kind of oil did you use thanks
did you reset the valves after you broke it in

REELAV8R

It's not unusual to have to run through valve lash again after break-in.

OMF

It's kind of hard to hear anything odd on that video. I noticed you have an auto transmission....check all the converter bolts

forman

it is when your lifters were not primed properly ,, stupid stuff happens

Jartanyon

@CaseyJones - Never thought about the balancer. I will check that today.
@Indiancreek - No press in studs. The new heads are AFR heads. Here are the new major parts:
- 180cc AFR Alum. Heads
- Summit Stage 1 Intake
- Comp Xtreme Energy 262/270 cam kit with lifters, chain, springs, etc.
- Comp Magnum Rocker Kit with High Energy Rods

@forman - I broke it in per Comps instructions. Parts are above. I used VR1 20/50 for break-in with Comp additive. I did not reset the valves after break in. I was planning my attack on how to do that with the engine running after I reinstall the dampers back into the springs. I don't think that is the knock, though, too low pitch. Lifters were primed when lash was set. We actually adjusted them individually instead of working across from each other.

@REELAV8R - Again, I think the sound is too low for that. I am going to readjust them, though. Any ideas on how to do that with the engine running? Drilled out valve cover? Lifter plugs?

@sstocker31 - I will try and see if I can get a better sound byte of it. Good idea on the TC bolts - I was reading some other threads where that was the problem.

Jartanyon

*UPDATE*

Here is a newer version of the video (Photobucket's compression sucks and it was hard to hear the noises). It's is slowed down 50% to hear the knocking better and an audio clip at the end of the video where I reduced the engine noise so you can really hear it:

https://vimeo.com/95975498

CanadaGrant

Did you use the old fuel pump pushrod and fuel pump or a new one? You can tell if it's a valve related knock or bearing/piston related by attaching a timing light to any plug wire. If the frequency or speed of the knock is the same as the timing light strobe, it's valve train related. If the knock is twice the speed, it's crank, rod, bearing, damper, flex plate related.

cardo0

if u wiped any lopes the rocker arms will be getting loose on those lobes.

pull 1 plug wire at a time to see if that kills the noise.

cardo0

REELAV8R

Sorry I just can't her anything of concern on that video either.
Must be the difference in video vs being there.
I have never adjusted the valves with the engine running but if I were to do it I think I would use an old valve cover with top cut for access to the rocker nuts. It sounds messy no matter how you do it with the engine running.
I think it's Isky who advocates it strongly as the only good way to adjust hydraulic lifters though.

Jartanyon

Nope. New fuel pump and new pushrod. Cool idea with the timing light - I am going to try that today!

@Cardo0 - I will try that too - thanks.

@REELAV8R - there is definitely something rubbing/knocking. It changes levels when walking around the car. I was going to cut out a valve cover to be able to do this while the car is running. Hopefully it is not too bad

gerry72

Check the heatriser on the exhaust manifold to make sure it's not bouncing to the tune of the exhaust.

To be honest, I can't discern anything going on in the video. Way to much mechanical and exhaust noise for me to pick out anything.

Also, EVERYTHING has the potential to make noise. You need to use a mechanic's stethoscope, a steel rod, a plastic tube or something to narrow down from where the noise is coming. Everyone is just throwing stuff out there for you to check and without some idea where the noise is, everyone is just guessing.

Belgian1979vette

Check if the noise is more pronounced from the bottom or the top. Check with a hose to listen to where it's coming from.

At this moment it sounds like a piston is hitting a head or some kind of conrod noise.

Jartanyon

So, after a noise hunt and involving my neighbor who builds engines, he thinks it is just the exhaust noise. It is definitely noticeable from the tranny back through the exhaust. I have tried all advice given to no avail. I am starting to wonder if I am going crazy

bluedawg

I couldn't view the video, "permission denied" but when I changed the top end on the l48 I had a knock on first start up, which wasn't noticed during the camshaft break in and it turned out to be the all thread in the water pump were the pulley mounts, I had it to far in and it was hitting the water pump housing in one spot. This next question sounds ementary, but after changing the top end and before starting did you change the oil? I've seen guys replace the intake manifold gaskets or head gaskets and have a knock afterwards from coolant getting in to the pan from the intake coolant ports. Like I said pretty elementary but it has happened. Good luck on your project! Blue

Jartanyon

Hey Blue - try it now. Password: knock
Interesting - worth a look at the water pump. Thanks! The entire engine was rebuilt outside the car which means all new fluids.

bluedawg

I couldn't tell by the sound on the video, but by your actions with the camera I'm guessing an out of adjustment rocker. Pull the valve cover, UN plug the ignition and rotate the engine over bump by bump. If you don't see any thing obvious, use a cut up valve cover or the deflector clips and adjust while the engine is running, if it's a rocker it will be more evident then. Put 100 miles on it and then readjust the valves. I've no clue who made the lifters or what there preload is suppose to be, but I've had comp hydraulic lifters that took a little while to quite down.

Jartanyon

Ok, here is another clip where you can definitely hear it - I refuse to believe this is just my exhaust.

https://vimeo.com/96229784
Password is knock