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.