Annoying Rattle in my '30 Coupe

[dlfrisch]

I have a very annoying erratic rattle coming from the right side of the dash or it seems like it is. Under over or behind, I can’t locate it ! I have installed or gasketed the windshield, the dash to gas tank cross member, re-sealed the cab / door columns, tightened hood hinge / hinge bars, re-gasketed the hood to radiator / hood to gas tank, installed soft rubber buffer around the cables (ignition, speedometer, amp wires, etc.) from engine to dash panel. All under the vehicle carriage - brake rods, clamps and anything that seems like it or they can possibility create a rattle has been fixed, tightened and / or hopefully cured, but I can’t get rid of the rattle. It is not a constant rattle. It only happens, when driving and I let off of the throttle. Letting off of the gas going down a hill or just on a cruising straight along drive on the highway the rattle comes on, when gas is let up and rattle is stopped or lessened when the gas is stepped up. I realize that, the drive train mechanical items do have a vibration effect, because they are not balanced. Maybe this situation is setting up harmonics with something else……WHAT ???

Any ideas or suggestions ?
Dave

[Big hammer]

Vacuum line behind trim around windshield ? It is routed thur fire wall up
behind trim on right side. Or just remove from baby's hand before it's ride:-)

[Clem Clement]

Look were the right rear hood end meets the body. Is the hood latch sloppy. Look for wear on the underside of the hood. Look for vertical motion on the hood rod at the rear. Have your copilot reach out or under the open window and touch the hood sections. Consider removing the hood.

[Y-Blockhead]

I had a rattle that was driving me nutso until I notice that my engine pan was cracked.

[Tom Elliott]

I had the same sort of noise in my 30 coupe. Drove me crazy trying to find out what it was. As it turned out the accelerator linkage was rubbing against the firewall. Might check that as well. Good luck finding your source of the noise, they can be frustrating.

[700rpm]

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My rattle like that turned out to be the throttle assembly vibrating against the firewall on the pass. side. I pried it out a little, and that was that.

[Mitch//pa]

just in case you have one of the hood shelf holders i had them rattle also

[Barry B./ Ma.]

Dave, I had a rattle like that in my 30 roadster that came from the left front and appeared mostly when going down hill, it came from the inside flange of the left front fender that was only about 1/16th. from the radiator bottom support. After a little bending the 4 year rattle is gone. Good luck, frustrating I know.

[Marshall V. Daut]

Good suggestions so far and unfortunately, I have experience ALL of them as noise makers in Model A's I have owned or worked on since 1966. I'd like to expand on what Clem suggested. I think his is the most likely candidate for attention after the other suggestions have been followed. I have often posted this same suggestion to similar questions posted here and on "Ahooga" because this is such a common source of irritating noise.
As Clem wrote, check that the hood stay rods are tight against the firewall. Often the large nut has worked a little loose through vibration or some previous mechanic didn't space the washers thick enough so that the nut could be drawn down tightly on the threads against the firewall bracket. Vibration here will telegraph through the passenger's compartment and sound as if it's coming from behind the instrument panel. While you're at it, check the 1/2" nuts on the front of the stay rods. Because of their remote location from the firewall, looseness here will not telegraph noise so dramatically as loose nuts against the firewall.
Let us know what you find, please. It might be a combination of all the suggested sources.
Marshall

[raprice22]

One last suggestion: I could be the rattling of the passenger door window. I've been trying to deal with that noise in my '30. Noises tend to travel, adding to the owner's frustration. Good luck.
Rog

[Gold Digger]

Don't know if this could be the rattle on your coupe but on my 30 roadster after removing the top and putting it back on, I had a vib-rattle at a certain speed that drove me nuts. I kept trying to tighten the wing nuts that held the top in place but to no avail. It turns out to be the windshield vibrating horizontally when it was closed all the way. I made a couple of shims out of some thin leather and slipped them over the stop brackets and haven't heard another vibration rattle since. "Knock on Wood".

[dlfrisch]

All very good suggestions : Only a couple of new hints as Mitch//pa said, check the hood shelf holders (I haven’t paid any attention to that ) and I will also, check the hood stay rods on the cowl and on the radiator where they are fastened.

If, I find the rattle answer (source), I will let everyone know, plus I’ll do a new thread.
Dave

[Tom Wesenberg]

On my 28 Phaeton the firewall bracket for the right radiator support rod is slightly loose, as though the factory didn't make the rivets tight enough. I will try to tighten the rivets when I have the tank off to restore the car, but in the meantime I adjust the left support rod to the correct length, then adjust the right rod to put a slight pressure rearward on the bracket, to hold it snug to the firewall.

I've never had a rattle from these radiator support rod brackets, but I do have quite a rattle under the car when I drive over railroad tracks, and I still haven't found the cause.

[CarlG]

Does the "annoying rattle" go away when you leave your wife at home?

[FRANK PKNY]

I never had a Model A that did not rattle, aren't they supposed
to rattle?

[SeaSlugs]

If you cant pinpoint it have someone ride along and have them start pushing on panels and trying to find where something is contacting. Maybe they can detect a more precise location.

[CA Victoria]

A couple items I found on mine when first brought it home:
Loose running board trim.
Cracked body at RH #1 body bolt.
Lower radiator shell was vibrating.

[mollydog]

I had a rattle that drove me nuts. Checked everything like you did. Sounded like it was coming from the right side near the dash. Turned out to be the tailpipe hanger. I loosened the clamp and installed some fiber heat tape (Like you use on headers). No more noise, Ahhhh. But now I can hear my wife!

Molydog

[Halswell]

I had a mate that had a squeek in his 29 pickup. It really annoyed him. He finally cured it by taking a can of 30 grade oil and oiling everything and I mean everything. There was nothing on that pickup that didnt have oil on it or in it. He carried out this process untill the squeek stopped. Turns out it was the front spring rubbing on the chassis.Merry Christmas.

[C26Pinelake]

Mine was the metal cover that covers the heater hole in the bottom right side of the firewall. It took my grandson 2 minutes to find what I could not locate in many drives ! Wayne