OM-4 Mirror 'ping' Sound: Causes and Consequences?

[yessammassey]

I have two mechanical cameras (FM and SRT101) that each have their own 'ping' that sounds when their shutters are tripped. I have seen some online discussions relating to other cameras (especially the FM/E/2 Nikons and many of the cheaper K-mount Pentax's) developing the same. I think it's a common issue, and mostly inconsequential.

Now I have added an Olympus OM-4 to my collection. Very nice condition, but needed new light seals. While I had it on the bench, I decided that I would replace the foam at the top of the mirror box, where the mirror makes contact when it flips up. It looked pretty worn out, too.

At first I placed some of the softer kind of light seal material up there. Immediately after installation, I noticed the pinging sound. Maybe the sound was there before, but I can't say for sure. It seems like it only came on after replacing the mirror foam. I decided to source some foam that was more like the original material that I had replaced. It's much lighter and less dense than the light seal foam. Still, the pinging is there.

It is loudest when the mirror flips up and down, but it can also be heard every time I wind on the film advance lever, and even when the film rewind crank is pushed down from its drawn out position.

Something inside is resonating like hell in this camera. With film loaded and outside, it's not very noticable, but when the camera is empty, it's pretty loud.

I've looked around and can't really find anything about OM-4 cameras having a ping like the FE, etc. There's one YouTube video of someone demonstrating a similar sound on an OM-4T, but that's all I've been able to find.

So what do you think? Is this ping unusual for an OM-4? Does it indicate or portend any potential mechanical issues? Could this have been caused by changing the resting angle of the mirror by putting in foam that was too thick?

 

[thuggins]

I've got a number of OM's, including a 4. They've shot thousands of frames and I've never heard a ping. They all have a similar ka-chuck sound.

 

[zanxion72]

It could be that the new strip of foamy material you have used is not thick enough, letting the mirror slam on something while hitting the ground glass box. I have tried my OM-4Ti and it does not sound like that.
Use something thicker and denser.

 

[MattKing]

It could be that the new strip of foamy material you have used is not thick enough, letting the mirror slam on something while hitting the ground glass box. I have tried my OM-4Ti and it does not sound like that.
Use something thicker and denser.

Or even better, source foam from someone like jon goodman who has extensive experience with the types of foam that are appropriate.