Strange "Clanking Noise" at Idle

[ilgrilleto]

Hello Everyone,

A few weeks ago I purchased a 1954 Ford Customline with the 239 Y-Block and Ford-o-Matic transmission in what i thought to be pretty good condition. I've changed all fluids, new plugs, wires, points, distributor cap, condensor, and adjusted valve lash and I've got to say it seems runs pretty good. That said, I've been trying to find the source of a "clanking" noise at idle with not much luck and was wondering if the experienced folks at the Ford Barn might be able to point me in the right direction. Hopefully it's something simple like an exhaust leak or noisy water pump, as the other options aren't great. Here's a link to a video if it running just a few minutes after startup with the choke off. The sound goes away as soon as the RPM's increase even slightly, it really only exists around idle speeds.

https://youtu.be/VNWB_oXtzJg

Any help would be greatly appreciated, thanks in advance!
Vince

[ford38v8]

See my answer on the early V8s forum

[ilgrilleto]

Haha, much appreciated, i'll pull the belt and see what happens!

[dmsfrr]

Before I watched the video I was guessing it might be the rivets and bolts from the flex-plate to the torque converter. The rivets working loose and cracks in the flex-plate is a known problem.

But the noise does sound more like it's coming from up front.

[ilgrilleto]

Hi Everyone,

Thanks for all the suggestions. Going forward I'm going to reply in this thread (the correct thread, my mistake originally) in the Late V8 forum so as not to confuse everyone.

A few updates:

- I've removed the fan belt which isolated the generator and water pump, issue still persists

- Using the longest length of tubing I had on hand, I listened to the fuel pump when running and it sounded fine to me

- The noise doesn't change in/out of gear, but does go away at higher rpms (by ear maybe a few hundred rpm more in enough to make it go away/drown it out)

- I did a valve adjust recently and used the method where I tightened the adjuster until the pushrods barely rotated, all pushrods looked good, none were dropped and none were bent.

- I played with the spring loaded valve on the passenger side of the "exhaust-crossover-pipe" (sorry not sure the technical term), but to no avail, it didn't really change anything.

I appreciate all the suggestions and advice, I'm going to keep chasing this down. Will head down to the parts store to grab a longer length of tubing/pipe to use as a makeshift stethoscope, hopefully that will help.

Thanks,
Vince

[fordor41]

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maybe a chip in the timing gears?

[dmsfrr]

Originally Posted by ilgrilleto

...
- I did a valve adjust recently and used the method where I tightened the adjuster until the pushrods barely rotated,
...

Does this procedure actually result in obtaining the correct valve gap???

[ilgrilleto]

Sorry, to be clear, the procedure was to essentially tighten the adjuster down to 0 lash, then back off a quarter turn (90 degrees) which theoretically equals 0.19" lash. Recommendations online suggested to tighten down until the pushrods put up a small amount of resistance when rotated, then back off from there. The procedure is here:

http://www.y-blocksforever.com/tech/html/valvelash.html

I will say that after this procedure the valve train was infinitely quieter, and the engine seemed to run quite a bit more smoothly. Feeler gauge confirmed that I was in the ball park of 0.19 on intake/exhaust so it was good enough for me.

[dmsfrr]

Ok thanks, with the 1/4 turn that makes sense now.

[darrell]

pull one plug wire of at a time.if the problem is in the crank or cylinder the noise will ease or go away.

[bobss396]

Do you have a heat riser that is banging around? Some of them IIRC had springs on them that would fall apart over time.

[ilgrilleto]

There is a heat riser on the exhaust crossover, but the noise doesn't appear to be coming from there when I used my makeshift stethoscope. I've also held the riser open/closed while the engine was running with no change.

As per darrell's suggestion, i'll try spark plug wires today and report back.

The local mechanic where I purchased the car offered to put it on the lift next week to have a look at the flex plate bolts, so hopefully the next few days/week will be fruitful.

[Daves55Sedan]

Originally Posted by ilgrilleto

I did a valve adjust recently and used the method where I tightened the adjuster until the pushrods barely rotated, all pushrods looked good, none were dropped and none were bent.

I never heard of that method.
I am pretty sure all Y-blocks should have valves gapped at .019" and the pushrods DO turn round and round while engine is running.
I tried to listen to the sound on the youtube video. Sounds to me like one or more of the valves are either so tight that they are hitting the top of the piston or too loose so that there is excess valvelash noise.
I recommend consulting with your shop manual and begin anew with a cold valve lash adjustment with engine not running. It will require turning crankshaft by hand a few times to get all the valves done. THEN run the engine and fine-tune the adjustment with engine at normal operating temperature and running using a feeler guage. This will require TWO people; one to hold feeler guage and the other to operate screwdriver and boxend wrench.
Hope you didn't bend any valves. That could mean destruction of valves and valve guides. Good luck.

[ilgrilleto]

Hi Dave,

Thanks again for replying to another one of my threads, if you're ever in the area, beer is on me I used that procedure with the engine cold, and now with the engine warmed up, lash on each intake/exhaust in in the ballpark of 0.017-0.019, so the method seemed to work OK. I double check for good measure, though i'm really hoping it's the flex plate/flex plate bolts.

Edit: I know how the original post sounded, so I cleared it up with this a bit down below:

Sorry, to be clear, the procedure was to essentially tighten the adjuster down to 0 lash, then back off a quarter turn (90 degrees) which theoretically equals 0.19" lash. Recommendations online suggested to tighten down until the pushrods put up a small amount of resistance when rotated, then back off from there. The procedure is here:

http://www.y-blocksforever.com/tech/html/valvelash.html

I will say that after this procedure the valve train was infinitely quieter, and the engine seemed to run quite a bit more smoothly. Feeler gauge confirmed that I was in the ball park of 0.19 on intake/exhaust so it was good enough for me.

Thanks,
Vince

[Daves55Sedan]

It actually could be that if you have the older type flexplate with the riveted mounting tabs and some of the rivets have come loose, it will cause noise at idle. I had one on a '55 air-cooled Fordomatic and had to replace it. But on mine, there were two rivets on one side that were not tight. It was enough to allow the converter to move about as it turned, but not nearly as much as I am hearing from yours, unless all your rivets are backing out.
You have a lot of noise. And yes, with this phenomenom, the noise goes away when get going pretty good because the torque of the engine clamps down on those loose rivets and prevents them from moving temporarily.

[wbedwards]

The torque converter could be indexed wrong on the flex plate. It was on my car.

[ilgrilleto]

Thanks guys for the suggestions and advice. I went under the car near the bellhousing, and the noise seems to be coming from closer to the engine I'm going to keep digging, but on Tuesday I should be able to get it on a lift which will be better than squirming around under the car on my garage floor.

[Ford blue blood]

Old info, don't remember the source....the fuel pump makes the noise, lengthen the flex line going into the pump by 1/3 more. Again, old info....

[Ole Don]

If the flex plate is good, try this. On a warm engine remove the fuel pump and start the engine, it will run for a minute or two. Listen fast. Fuel pumps have been known to make the noise you have.

[BN]

My 1956 292/Fordomatic had a noise that sounded just like that, and went completely away at just above idle. I removed the flywheel and it had loose rivets which hold the mounting tabs to the flywheel. I replaced the old flywheel with a single piece 1957 flywheel which solved the problem.

[dmsfrr]

Have you checked the crank damper pulley? If it has a weight ring it may loose, about to come off.
The rubber layer dry rots and the ring may have slipped and is hitting something.

[Daves55Sedan]

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]

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

[darrell]

often these engines will spin a wrist pin bushing and make a noise like this.but it takes some time and yours started suddenly.if youve got good oil pressure dont worry about it.

[Alaska Jim]

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

[fiddy6]

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Is there any way to inspect these flywheel/flex plate rivets without pulling the transmission?

I think I have a similar sound at idle that goes away off idle.

[wellcraft17]

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]

Originally Posted by fiddy6

Is there any way to inspect these flywheel/flex plate rivets without pulling the transmission? ....

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.

[fiddy6]

I was looking through the air inlet and outlet. I see the inspection plate now. Thank you.

[dmsfrr]

Originally Posted by fiddy6

I was looking through the air inlet and outlet. I see the inspection plate now. Thank you.

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]

Originally Posted by fiddy6

Is there any way to inspect these flywheel/flex plate rivets without pulling the transmission?

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]

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