Is this normal - pulsating PCV valve and vibrating hose? - Vintage Mustang Forums

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post #1 of 3 (permalink) Old 11-09-2003, 03:11 AM Thread Starter
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Join Date: Mar 2001
Location: Suisun City, CA
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I was checking out the car prior to next weeks dyno testing and looked for a leak at the PCV hose. When I put my hand on the hose, I felt pulsations in the hose and heard the ball inside the PCV valve bounding up and down. Is this normal? It seems to me that the vacuum should be constant and hold the ball into an open position, not having the check ball openinng and closing rapidly. This tells me that my vacuum is pulsing which means that one or more cylinders is not operating correctly. True? False? Could it be that I have a valve adjusted too tight and it is not closing all the way.

Could someone tell me whether the PCV valve on their 302 is "bouncing" the checkvalve when the engine is running? What do you suppose this indicates?

Perplexed on this one. Maybe this is the signal of what is the illusive problem I have been chasing for so long.


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post #2 of 3 (permalink) Old 11-09-2003, 09:02 AM
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The 289/302 in my 65 just started doing that a couple weeks ago. It does it mostly, and loudest when cold. I was thinking that the pcv went bad. I plan on picking up a new one, hoping that is all it is. Maybe I should put the vacuum gauge on and see if anything has changed.

65 289 Holley 4160, F4B, Doug's Tri-Y Headers, 3.25 T-loc, coupe (father, son and daughter project)
64 1/2 coupe 289 4v, D-code (looong term puzzle)
64 1/2 conv 289 4v, D-code (long gone)
68 289 2v sprint 'B' coupe - Bone Stock (Holley 4412, 500 cfm 2v) SOLD, gonna miss that one.
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post #3 of 3 (permalink) Old 11-09-2003, 10:42 AM
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Sounds like this might be a good time to do a compression/leak-down test ! :p
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