1968 Charger 440 Motor Knocking Sound

[Chris 69]

Need some advice. My 440 in the charger has developed a knocking sound.

Oil level is good.
Oil pressure is good.
Temperatures are normal.
Coolant is full.
Motor doesn't seem to lack power.

I used a 1" dowel to listen to various areas of the motor. Sound seems to be coming from the passenger side front of the motor. Could hear it through the fuel pump, so replaced it. The lever on the old fuel pump seemed to be loose. The new fuel pump did not solve the issue. That is the only work I've done so far.

The sound seems to be loudest through the water pump housing and also on the front of the passenger valve cover.

Any suggestions? A link of the running motor is below. Knocking sound is clearly audible in the video.

https://youtu.be/b69TIpfU4AA

Thank you, Chris

[doctor4766]

Might be a dumb question but did you replace the steel rod behind the fuel pump too?
Once they wear down there could potentially be a knocking noise, along with reduced fuel being pumped. 

[torqueflite]

It looked to me like the water pump had a bit of end float , you could try disconnecting the all the belts and then run it , see if the noise is
still there .. easy check)

[70 sublime]

Right at the very first part of the video it looks like the water pump pulley floats in and out a little
Think I would take the belts off to see if the noise stops
Could be the water pump getting ready to go and is moving in and out to drag to make the noise

[c00nhunterjoe]

The tone and way it changes pitch off load tells me its a rod or wrist pin. Hard to be exact in a video, but highly unlikely its a pushrod or water pump. Pump is cam driven so 2:1 ratio and the noise is crank rotational.

[white]

I hate to say this but sounds like a wrist pin to me, had a 64 impala with a 327 that did the exact same thing. I hope it is not.

[Chris 69]

Might be a dumb question but did you replace the steel rod behind the fuel pump too?
Once they wear down there could potentially be a knocking noise, along with reduced fuel being pumped. 

Thank you for the reply. I did not replace the steel rod. The rod that's in there now has about 4,000 miles on it. Same as the rest of the motor. I wouldn't think it would be worn down at this point.

[Chris 69]

Right at the very first part of the video it looks like the water pump pulley floats in and out a little
Think I would take the belts off to see if the noise stops
Could be the water pump getting ready to go and is moving in and out to drag to make the noise

It looked to me like the water pump had a bit of end float , you could try disconnecting the all the belts and then run it , see if the noise is
still there .. easy check)

Thank you. I'll try removing the belts next and see if that solves the noise. If not, guess I've got some major work ahead.

[Chris 69]

The tone and way it changes pitch off load tells me its a rod or wrist pin. Hard to be exact in a video, but highly unlikely its a pushrod or water pump. Pump is cam driven so 2:1 ratio and the noise is crank rotational.

I hate to say this but sounds like a wrist pin to me, had a 64 impala with a 327 that did the exact same thing. I hope it is not.

Just looked up rod knock on youtube, and there was a V8 mustang that had a "rod knock". The sound from the youtube video sounded very similar to my car, unfortunately.

Is there any way to verify if the rod or wrist pin is failing without pulling motor? I assume the answer to this question is the motor has to come out, but thought I'd ask anyway.

[c00nhunterjoe]

You could try pulling plug wires to isolate the cylinder and then drop the pan and pull the cap for a rod. But doubtfully to check the pins in car without serious work.

[cdr]

Might be a dumb question but did you replace the steel rod behind the fuel pump too?
Once they wear down there could potentially be a knocking noise, along with reduced fuel being pumped. 

Thank you for the reply. I did not replace the steel rod. The rod that's in there now has about 4,000 miles on it. Same as the rest of the motor. I wouldn't think it would be worn down at this point.

I would still check the fuel pump rod, I had one go bad in 200 miles.

[Chris 69]

I would still check the fuel pump rod, I had one go bad in 200 miles.

Thank you cdr. I do have a new spare steel fuel pump rod to try. Also when I bought the car, it had an electric fuel pump. I installed the mechanical, but left the electric in place. I'm going take the mechanical pump out completely and rewire/plumb the electric pump to rule in/out the mechanical pump and components.

[Chris 69]

Hopefully the electric pump still works. I did that change in 2007.

[doctor4766]

Just pull the rod out and compare the length to the new one you have.
Probably quicker...

[Chris 69]

Finally got around to doing some more checking on the motor. Ran the motor with belts removed and electric fuel pump. Still has knocking sound. Removed valve covers. None of the rockers/pushrods are loose (bumped the starter to check different positions).

I guess next step is to pull the motor. Check the wrist pins as c00nhunterjoe mentioned.

Motor has only 5500 miles on it....

Here's a link to the motor idling: https://www.youtube.com/watch?v=yi97qmoazA0&feature=youtu.be

Any other suggestions?

Chris

[will]

Just a thought, could it be a torque convertor bolt? I also put a bolt that was too long in my harmonic balancer once. It would tap against the timing cover and sounded close to that. Just a couple of clues before you yank that sucker out of there.

[BSB67]

Just a thought, could it be a torque convertor bolt? I also put a bolt that was too long in my harmonic balancer once. It would tap against the timing cover and sounded close to that. Just a couple of clues before you yank that sucker out of there.

Always check this.

[Chris 69]

Just a thought, could it be a torque convertor bolt? I also put a bolt that was too long in my harmonic balancer once. It would tap against the timing cover and sounded close to that. Just a couple of clues before you yank that sucker out of there.

Thank you for the advice. There's no torque converter on my car as it's a 4-speed. I'll check the harmonic balancer and any other exposed bolts on the rotating items and see if there's any issues. I'd guess that since it ran without the noise for 5000+ miles that if a bolt is an issue, it would have to have loosened and backed out.

[rollo1504]

Hey,

I bought a 1968 Dodge Charger R/T in October 2018 and a friend of mine was noticing a knocking-like sound which I did not hear at the very beginning.

First I was discussing with him and telling "I can't hear anything" but as the days went by and his opinion was always in my mind I kept on hearing to the idling sound of the charger several times and in the end I also could hear the strange noise my friend was telling about.

As the engine was running awesome and was also completely rebuilt and stroked to 505 with around 1000 miles on it I was very concerned about it.

So I asked my friend again and he suggested to check the rocker arms. I agreed. Finally we found out that the rocker arms were already levigated ... Hope I used the right english word (levigated) that you understand what I mean.

It looked to me that the former owner was trying to save money at the wrong spot.... :-(

This Aluminum Roller Rocker Arm Kit was installed:

https://www.manciniracing.com/b15alrowibih.html

So right now we are replacing them with new rocker arms with bronze bearings.

In general I really do not understand why there are rocker arms available on the market or even being installed without bearings.... Should not always only rocker arms with bearings being installed? It is just a thought as rocker arms moving back an forth almost said 1.000.000 times so from my point of view it is vital to have them installed WITH bearings.....

I have enclosed a picture that you can see how one of these rocker arms looks like. The pic does not come with best quality but it should be enough for you guys to see the wear....

End of the story....

Maybe it helps you to find the culprit before disassembling the whole engine...

Keep up looking!!!

All the best

Roland

[BSB67]

Aluminum rocker arms have been around forever.  Quality aluminum rocker arms are absolutely fine for hydraulic cam and most solid lifter applications, street and race.

If they are elongated in a meaningful way, it's either because of a past or present oilling problem, or there is a quality issue with the rocker.

I don't see anything wrong with that rocker, but you should run a shim between the rocker arm and the shaft hold down.  Especially if you're using the factory hold downs, with aluminum rockers when using springs between the rocker pairs.

If your motor had a barely audible nose, it may, or may not be in the valve train, it may or may not be the rocker arm.  Did you adjust the rockers before you tore it apart to see if that made a difference?  If you ever looked at a factory original rocker arm, you would understand why an elongated rocker arm would likely not be the noise.

[c00nhunterjoe]

It doesnt get more "clankity clank" then a stock rocker on a shaft.... ive run aluminum rockers with bushings on many high spring pressure, high rpm engines without a problem. Again though, from that photo, i cant see anything wrong other then where its been rubbing on something but russ already covered that.

[redgum78]

I had a noise very similar to yours in my 400bb in my Charger. Sounded like behind the water pump and near the fuel pump. I pulled the fuel pump, checked the fuel pump rod, pulled the distributor and checked it just in case.

I was starting to think piston pin but pulling plug leads made no difference.

In the end I decided to take off the timing cover and check the chain and gears as it sounded like that area.

Turned out it was the cam gear had lost the tip of a tooth. Older factory style gear with the plastic coating. see pic.

[redgum78]

I just listened to your second video, the noise seems too fast for the cam gear. Might still be worth a look if the motors coming out anyway, there is always the off chance it is the crank gear or something weird with the chain. 

[garner7555]

My dad had 2 wrist pins "stick" in his Roadrunner.  It developed a knock and we couldn't figure it out, the engine only had 50 miles or so on it, but it had been assembled and in the car for 15 years or so (he will let it sit for 3-5 years without firing it up).  Still not sure what caused the wrist pins to stick, one person told us it could have been from sitting too long between being run.      Anyway, he just had to do a complete rebuild on it.  I hope this isn't your problem but it does sound similar.  The ones that stuck on his engine were number 1 and 2  (the front 2 cylinders).

[timmycharger]

I have been battling similar issues since doing a refresh of my 440 a few years ago.  2 cams, 2 sets of rockers, pushrods, lifters later, still have the noise.  I officially gave up and plan to just drive it till it explodes LOL.  

My issue is likely similar to what Garner7555 just posted about his Dad's RR.     When I had my pistons/rods out of the engine, a few were very tight so I brought them to a machine shop to clean up.  Ironically, when I pull the spark plug cables off of the cylinders that had the tight/cleaned up rods, the noise pretty much goes away.  


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