Looking for source of the rattle in my 76

[John_in_VA]

47 minutes ago, John76 said:

Looks like your check valve may have been hitting the fan. Cause of rattle??

It should have a bracket on the front valve cover bolt.

 

 

 

 

I don't think I've ever seen that bracket - cool!

(You should replace your "Yankee hose clamp" with a Euro version as seen on Eissmann's hose).

[Eissmann]

I ordered the shackle yesterday from Maximillian. Got the email today saying the item is no longer available. I ordered the slip ring from another source. Crossing my fingers! 

[John76]

16 hours ago, John_in_VA said:

You should replace your "Yankee hose clamp"

It goes well with the Yankee check valve. ?

Now...about that cracked hose?  I try to keep my original 47 year-old parts (mostly).

[John76]

2 hours ago, Eissmann said:

I ordered the shackle yesterday from Maximillian. Got the email today saying the item is no longer available.

These came on all '75-'76 cars.  Someone must have a used one somewhere!

Not a big deal to make your own bracket. All it does is prevent the air hose and check valve from wiggling loose and hitting the fan.

 

John

[Eissmann]

I'm planning to make my own shackle but hope to find one like our cars came with. 

[Milo]

 =

Edited March 12, 2022 by Vladimir

[Eissmann]

The check valve was definitely coming into contact with the fan and making a rattle. One can see the marks on the fan blade. 

The last time I drove the car the exhaust manifold  noise was especially bad when the pipe finally worked it's way out of it's home. 

This isn't the last of the rattles, but I probably avoided catastrophic damage to the fan. 

[Son of Marty]

If your not in Calif. all that crap belongs in the garbage or your neighbors pool, and you car returned to it's German roots.

Edited January 22, 2022 by Son of Marty

[Eissmann]

1 hour ago, Son of Marty said:

If your not in Calif. all that crap belongs in the garbage or your neighbors pool, and you car returned to it's German roots.

I appreciate originality as much as most anyone, The smog stuff is only there because the state of Cali requires it.

  

[Eissmann]

Made my own shackle using a right angle bracket that was laying around. Not pretty but it does hold the check valve securely. 

[Eissmann]

As I look around the engine bay I have found a stray bolt that's about 2 inches long. It landed on the front suspension subassembly, just below where the air pump bracket attaches to the motor. Maybe it fell off that bracket?  There's a lot of stuff blocking my view of the air pump bracket so I can't see whether any bolts are missing there. The pump feels solid when I try to move it, but who knows what happens when the motor is running and spinning that pump at higher rpms.

 

I am thinking of temporarily removing the fan belt from the air pump to see if there is much change in noise. Is there any risk in running the car without the air pump belt?

[John76]

1 hour ago, Eissmann said:

Is there any risk in running the car without the air pump belt?

No....but before you do that, remove that mystery bolt from the front suspension. 

[Eissmann]

I've been following up on some possible causes for The Noise.  Tapping on the bell housing with a wrench I could hear the exhaust resonator ring like a belI. When I muted the exhaust and tapped the bell housing, it didn't ring! 

 

Next I re-installed the exhaust hanger bushings at the transmission. Referring to the REalOEM parts book and some pictures of other exhaust hangers on other threads here was a big help. 

 

The car is still noisy but it is much quiter than it was.  I took my wife for a ride and she noticed the difference right away. Time to move on to other issues and start enjoying this car more! 

 

It took me a while to get around to it, but 2002iii had the right idea early on in this thread. Thanks 2002iii

 

Edited February 17, 2022 by Eissmann
I forgot to thank 2002iii for offering the solution!