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1986 Spider Veloce
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264 Posts
Discussion Starter · #1 ·
While working on the car I noticed some rubbery stuff hanging off around the metal connection on the plenum that connects to the hose that leads to the AAV.

I "cleaned it up" a bit by pulling off the part that was loose and now I'm concerned I have a leak there.
  1. Is there a way to check for that?
  2. how would I seal that off? Does it unscrew and needs tape? Some kind of sealant?
I tried to search the forums, but most of the threads talk about addressing the AAV itself (which I also need to do, but want replacement hoses before I mess with the ones attached).

Thanks in advance for any guidance!

1692801
 

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2,224 Posts
If you have a leak there, it will cause a rough idle.
With the car running and idling, spray some starting fluid or something similar at the joint. If the idle changes, you have a leak. Same applies to any other joint on the intake. I thought that was just a press fit. Is it loose? Some type of gasket maker/sealant should stop a leak if needed.
 

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1986 Spider Veloce
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264 Posts
Discussion Starter · #3 ·
Thanks!
my engine kinda vibrates on idle, feels worse then it was before i started to work on the car. (Was on my list to investigate- maybe this is it?!)

Don’t have starting fluid on hand, carb cleaner work?

it’s not loose and doesn’t seem to turn but haven’t tried real hard.
 

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1986 Spider Veloce
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264 Posts
Discussion Starter · #4 ·
I tried it with carb cleaner - no idle change at all.

I'm hearing what I think is a hissssss right around that area, or under the plenum or oil vapor separator - it's around that area. Might have gotten softer as the car warmed up.

This could all be in my imagination too :confused:.

I'll start a hunt in earnest for a vacuum leak - I think it could be related to my new engine vibration. (I changed the gap on my spark plugs too - that could cause it?)

Anyway - regarding this connection - it's not lose at all. And the carb cleaner didn't change anything on those joints.

So - onward!
 

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I tried it with carb cleaner - no idle change at all.

I'm hearing what I think is a hissssss right around that area, or under the plenum or oil vapor separator - it's around that area. Might have gotten softer as the car warmed up.

This could all be in my imagination too :confused:.

I'll start a hunt in earnest for a vacuum leak - I think it could be related to my new engine vibration. (I changed the gap on my spark plugs too - that could cause it?)

Anyway - regarding this connection - it's not lose at all. And the carb cleaner didn't change anything on those joints.

So - onward!
Sounds like progress. At the dealer, we used starting fluid and/or B12 to find leaks because if one existed, that would definitely show it. I have also lift up on the intake plenum and found a change if it has a leak.
 
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1988 Spider Quadrifoglio
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335 Posts
When the car is cold, the air going past the auxiliary valve and into the plenum makes a hissing noise. The idle air bypass area can make a slight noise too. It's not necessarily a leak.
 

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Carefully check/examine the condition of the intake hoses between the plenum and the head. The rubber is prone to cracking and leaking with age and heat, and could be the source of the hissing you hear, and the rough idling you're experiencing.
 

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1986 Spider Veloce
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264 Posts
Discussion Starter · #8 ·
yeah - the hoses are old and all will be replaced - when I had my AAV off they looked "ok" inside from what I could see, but the ends were cracking and they were stiff.

While I'm waiting to get that finished I wanted to see if I needed to seal this attachment to the plenum - looks like no.. (or "not yet" :) )
 
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