Strange "Clanking Noise" at Idle
- Thread starter ilgrilleto
- Start date
Daves55Sedan
Well-known member
One more thing to check. Look at the generator mounting bracket to see if the bolt that holds it to the side of engine is missing. If it is, that bracket will sway back and forth a little bit and hit the side of the engine, making a loud noise.
ilgrilleto
Junior Member
Hey Everyone,
Apologies for the lack of reply, life has been a bit crazy and also forum notifications don't seem to be working properly. I still can't seem to get to the bottom of the noise, but thanks to everyone for their advice. Troubleshooting has been a bit of a saga, so here are the updates:
A few days after my last reply I started noticing some misfires, long story short, bad plug wires. With new plug wires in, it still wasn't running right so I pulled the valve covers and Cylinder 4's exhaust pushrod was a bit off center, when I loosened the adjustment nut, it fell straight in. Thankfully I was able to fish it out with a magnet on a stick and it wasn't bent. Turns out the bolt to secure the spark plug wire holder was too long and was interfering with the pushrod. Bolt removed, pushrod re-installed, readjusted valve lash on Cylinder 4 for good measure and fired the engine up.
Still not running great, pulled all the plugs and they were pretty fouled up so cleaned them up and voila, engine now runs great. That said, the noise is still there, though not as prevalent. This is the most recent video I just took. When the engine is fully warmed up, the noise can be heard with the hood close as it idles in my driveway. It sounds like it coming from around the oil pan area when under the car, and around the back of the engine when around the sides. When in front of the car it sounds like the water pump. Guess it's one of those cases of the sound bouncing around.
https://www.youtube.com/watch?v=dZJ1PDEbUJ8
If you notice in the video too, it almost seems like it's got a small miss. I know these engines don't idle perfectly smooth, and you can barely notice it, maybe I'm just being paranoid. My big concern is worn bearings. If you guys have a second, let me know what you think, and as always, thanks again!
Vince
Apologies for the lack of reply, life has been a bit crazy and also forum notifications don't seem to be working properly. I still can't seem to get to the bottom of the noise, but thanks to everyone for their advice. Troubleshooting has been a bit of a saga, so here are the updates:
A few days after my last reply I started noticing some misfires, long story short, bad plug wires. With new plug wires in, it still wasn't running right so I pulled the valve covers and Cylinder 4's exhaust pushrod was a bit off center, when I loosened the adjustment nut, it fell straight in. Thankfully I was able to fish it out with a magnet on a stick and it wasn't bent. Turns out the bolt to secure the spark plug wire holder was too long and was interfering with the pushrod. Bolt removed, pushrod re-installed, readjusted valve lash on Cylinder 4 for good measure and fired the engine up.
Still not running great, pulled all the plugs and they were pretty fouled up so cleaned them up and voila, engine now runs great. That said, the noise is still there, though not as prevalent. This is the most recent video I just took. When the engine is fully warmed up, the noise can be heard with the hood close as it idles in my driveway. It sounds like it coming from around the oil pan area when under the car, and around the back of the engine when around the sides. When in front of the car it sounds like the water pump. Guess it's one of those cases of the sound bouncing around.
https://www.youtube.com/watch?v=dZJ1PDEbUJ8
If you notice in the video too, it almost seems like it's got a small miss. I know these engines don't idle perfectly smooth, and you can barely notice it, maybe I'm just being paranoid. My big concern is worn bearings. If you guys have a second, let me know what you think, and as always, thanks again!
Vince
Alaska Jim
Well-known member
I have had fuel pumps make similar noises, also I have heard extremely loose timing chains hit the side of the front cover , and make similar noises. just a shot in the dark not being there in person. good luck and let us know what and when you find the problem
wellcraft17
Senior Member
I have the same noise on my 56 292 when the idle is set to low, been that way for years. I found the solution was to bump the idle up a hair and the noise disappeared. The noise is definitely coming from inside the engine and I guess it could be rods or wrist pins. I do have very good oil pressure, 40 idle, 55-60 at highway speeds.The other suggestion from a guy at the machine shop was the cam shaft might be moving back and forth slightly, I found that was a little hard to believe but he rebuilds a lot Of engines a year and probably has seen everything.
dmsfrr
Well-known member
Is there an inspection cover on the bottom of the bellhousing? Approx 2 x 6 inches.
Example bellhousing photo: air cooled automatic, thru mid '56.
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dmsfrr
Well-known member
You're welcome.
The removable air duct on the drivers side could help with the view inside too, only 4 bolts holding it on.
And it's a larger hole.
Daves55Sedan
Well-known member
I don't see how that will help. The little rectangular shaped inspection hole at the bottom of the bellhousing will allow you to look, but you can't tell if the rivets are loose and there's not enough room to grab the flywheel and tug it back and forth to see if there is movement.
All I can say is, decades ago, my '55 had a noise at idle that you could hear loudest by lowering your ear down by the back of the front tire. I pulled out the trans and discovered the rivets on one side of the flexplate loosened up. But that was in the '70's and I had a flexplate from a local junkyard the next day. I still have the bad one in my garage. I think the only way to be sure is to tear the trans out and get the flexplate off.
ilgrilleto
Junior Member
Hey Everyone,
Sorry again for the delayed reply, I've decided to stop trusting the notifications at this point. First off, thanks again everyone, I greatly appreciate all the help. Not sure why or how, but after a new set of plugs and a few drives, the engine seemed to sort itself out. No more misses, and you could only just hear the noises if you were listening for them. It's all a bit confusing, however, at this point the car is off to a new owner who is fully aware of this saga, but all reports indicate that the car is still running fine. Interestingly enough, he did report that the engine ran noticeably better without the factory oil-bath air cleaner, but as long as he's happy, I'm happy.
Thanks,
Vince
Sorry again for the delayed reply, I've decided to stop trusting the notifications at this point. First off, thanks again everyone, I greatly appreciate all the help. Not sure why or how, but after a new set of plugs and a few drives, the engine seemed to sort itself out. No more misses, and you could only just hear the noises if you were listening for them. It's all a bit confusing, however, at this point the car is off to a new owner who is fully aware of this saga, but all reports indicate that the car is still running fine. Interestingly enough, he did report that the engine ran noticeably better without the factory oil-bath air cleaner, but as long as he's happy, I'm happy.
Thanks,
Vince