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Old Nov 15, 2025 | 07:52 PM
  #1  
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Default Mystery Joint

Hi Everyone,
I am new to this forum and a new owner of an 81 Vette with an 4-speed.

The car runs well for its age, but there are lots of things to be done.
Today I found my first mystery.
I was looking closely at the engine and found the small plastic joint (about 3”) pictured below sitting behind the water pump.

it seemed like it belongs to the air intake somewhere, but I searched everywhere I could see for an opening in need of this joint and couldn’t find where it belongs.

Any and all help would be appreciated.
This is the small plastic 90 degree joint in need of a home.
This is the small plastic 90 degree joint in need of a home.

Thanks in advance!!
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Old Nov 15, 2025 | 07:57 PM
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Did you remove your air filter base and look underneath?
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Old Nov 15, 2025 | 07:58 PM
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how big is the id of the round pipe and the flat flange?

81 I am not sure

Last edited by 20mercury; Nov 15, 2025 at 08:06 PM.
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Old Nov 15, 2025 | 10:36 PM
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Originally Posted by 4-vettes
Did you remove your air filter base and look underneath?
Looks like it would feed a pcv hose into the base of a breather
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Old Nov 16, 2025 | 07:04 AM
  #5  
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Originally Posted by 4-vettes
Did you remove your air filter base and look underneath?
No. I only removed the top and the filter. I will remove the base today and take a look.
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Old Nov 16, 2025 | 09:22 AM
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Originally Posted by Erich81
Hi Everyone,
I am new to this forum and a new owner of an 81 Vette with an 4-speed.

The car runs well for its age, but there are lots of things to be done.
Today I found my first mystery.
I was looking closely at the engine and found the small plastic joint (about 3”) pictured below sitting behind the water pump.

it seemed like it belongs to the air intake somewhere, but I searched everywhere I could see for an opening in need of this joint and couldn’t find where it belongs.

Any and all help would be appreciated.
This is the small plastic 90 degree joint in need of a home.
This is the small plastic 90 degree joint in need of a home.

Thanks in advance!!
looks a little "bubba" ish
Reply
Old Nov 16, 2025 | 11:30 AM
  #7  
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Alternator wire grommet?
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Old Nov 16, 2025 | 04:50 PM
  #8  
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Default Mystery solved!

The joint is actually just a piece that had broken off of a larger hose that connects to a solid pipe from the air pump. It broke off at the point where the hose becomes a bellows.
The hose has been replaced with a new one.
thanks for everyone’s input!!
The circled hose is what the mystery joint is from.
The circled hose is what the mystery joint is from.
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Old Nov 16, 2025 | 05:58 PM
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Glad to hear you found it. I would have never guessed that. Although that air pump would have been in the bin 45 years ago if that were my car! LOL.
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