Engine Knock, Opinions Before I Go In

[Mac Stew]

Hello Everyone, new to the forum so hopefully I follow the rules, if not please let me know. I have a 1972 Dodge Charger with a 1973 360 in it. It had been sitting a little while and when I started it up I have a noticeable knock. Sounds like it is coming from the top end on the passenger side but not 100% sure on that, I have uploaded a video to youtube so you can here it I will hopefully be getting into the engine early next week when I am on vacation for a week but wanted opinions and educated guesses on what it is, let me know what you think and I will post back when I find out what it is, thank you

 

[dvw]

Many times the push rod will spear the rocker.
Doug

 

[oldbee]

Collapsed lifter maybe?

 

[mmissile]

If the oil PSI isn't dropping....look at the above suggestions. Those would be my first guesses.

 

[Mac Stew]

Oil pressure looked good but I didn't run it long once I heard the knock, I checked a couple things quickly and shut it down. I won't have a lot of time until next week but hopefully tonight I can at least pull the valve cover and check the rocker arms and for a collapsed valve. I will report back with what I find if there is interest, thanks for the suggestions so far guys

 

[mccoymail]

X2 on lifter.

 

[Mike67]

Just pop the valve cover off and take a look, it shouldn't take but a few....but it might make you sleep better...or give you nightmares....
Hope you find it!

 

[PurpleBeeper]

I will think happy thoughts that it's just one bent pushrod. You should be able to find it easy. If it were me, and it is a stock top end, I'd have a couple extra 360 pushrods & rockers handy from the junkyard & a set of valve cover gaskets before I started. That is NOT a rod knock

 

[khryslerkid]

Welcome Mac! Hit the "Welcome Wagon" when you get the time and don't forget some pics of your car.

Sometimes when an engine sits for a long time, a pushrod for a valve will have the cup in the lifter bottomed out and it will stick at the bottom and create slack in that rocker to lifter. Sometimes just running it at idle until the engine reaches operating temperature, will let the lifter pump back up again. Don't rev the engine too much if the tapping is still going on. Removing the valve cover on the side that the noise is coming from and doing a inspection, will tell you which one it is. You will have to rotate the engine through its cycle to watch each valve come up to check for play. Removing the spark plugs will make it a lot easier. Make sure all of the rockers look wet, that they are getting proper oiling.
Good luck and keep us posted.

 

[Mac Stew]

Thanks for the welcome khryslerkid, unfortunately I'm not gonna have time tonight to do anything but I have cleared some time tomorrow night to pull the valve covers so I should be able to update you tomorrow night on what I find. In the mean time here is a picture of the car when I bought it 4 months ago, as you can see there is some slight front end damage, PO told me that it came out of gear when parked and rolled face first into a ditch. I have since replaced the front valance and fenders but that is why it has been sitting for the last 4 months, finding the parts in good condition for a decent price in southern Ontario was not an easy task. When I first bought it I had it up and running and there was no knock, it only appeared after sitting for 4 months so a stuck lifter or bent push rod is very plausible. Anyways I will update tomorrow night with the results, thanks again

 

[Darthomas]

Sea-Foam in the oil.
Not too much on an old engine.
Keep using it forever and one day when you open the engine, it will be be shiny clean instead of varnishy and black.
If it's a lifter it could clear up very quickly, but it's likely a sign of varnished parts.

 

[Mac Stew]

Hey guys so I pulled the spark plugs and valve covers and took a look, I attached some pictures, they aren't great but gives a little bit to look at. As you can see spark plugs are black, I have new ones ready to go when it goes back together, don't think they are bad enough to cause a problem. Looking under the valve covers and everything looks pretty good just looking at it, no push rods through the rocker, no really loose rockers or valve lash, all the push rods seemed good (didn't take them out yet to see if they are bent yet), turned it by hand and everything looked good and seemed to function as it should. Only thing I could find that might be causing the noise is a couple rockers arms can move side to side and make a decent noise doing so. Here is a video

 

[khryslerkid]

The side play is normal. Up and down play needs to be checked when the valve is completely closed as in doing a valve adjustment on adjustable rockers. Did you rotate the engine and check each valve when closed?
I'm still thinking you have a collapsed lifter, just from sitting.

 

[Mac Stew]

I rotated the engine by hand and checked every rocker and push rod by hand when the valves were closed and there was no up and down play in any of them. I am just a backyard mechanic and not an expert by an means, that's why I am here getting opinions, shouldn't I get some play in a rocker and push rod if I have a collapsed lifter? I am thinking next step is to get an old set of valve covers and cut the top off so I can look and hear better while its running and not get oil everywhere, what do you think? Anything else I am missing or should be checking?

 

[69L48Z27]

I tried to listen to the first video and really didn't hear a lot.

Exhaust leaks can sound like engine problems sometimes too.

Does the noise follow the RPM when you rev it higher?

 

[khryslerkid]

I'd put the valve covers back on, start it up and see if it's still there. Just releasing the pressure off of the one that wasn't pumped up can let it go back into position again.

 

[dvw]

This will make a mess but if there is something loose you'll find it. Pull the cover from the side you think makes noise. Have a helper start the engine. Quickly (to prevent a big mess) rest your finger on each rocker a few seconds at a time. You will be able to feel the offending cylinder, intake or exhaust. Feel nothing? Then the valve train isn't making the noise, go elsewhere.
Doug

 

[Mac Stew]

Listened to my first video again and noticed the sound cut out and wasn't very clear, I have had exhaust leaks on other cars before and it doesn't sound like that to me, could be wrong but most exhaust leaks I have dealt with sound more like a tick then this. I think I am going to take khryselrkid's advice and put it back together tomorrow night and fire it up and see what happens while I try and track down some old valve covers I can cut up. If the noise is gone that's great and I can finally take her for a spin, if its not I will take a better video and repost it so you can hear, there is a clear noise that shouldn't be there. Once I track down the valve covers I can get a better idea with the engine running, if I can't find anything like Doug said I will have to start looking elsewhere, thanks guys

 

[Mac Stew]

Oh and yes 69L48Z27 the noise follows the speed of the RPM's, it stays close to the same in terms of how loud but it gets faster as the RPM's climb

 

[oldbee]

Just a thought- broken valve spring(anybody?). Don't ever remember hearing one myself. Mac just pull rt.cover and lay your fingers over each rocker one at a time,won't take very long at all. Noise sure sounded louder on rt.side..