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Join Date: Dec 2006
Location: Middle Georgia
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Would these 2 situations produce same sounds?

Forgive me if this is a stupid question......

Do you get the same sound with loosely adjusted valves as you would hear with a rocker arm issue (problem)? I guess there could be a few modes of failure for a rocker,...what if one were to crack (in example,..and as far as sound...)?

My guess is that the resulting sound is quite similar (of course, depending upon the rocker failure)...

...any pics of rocker failure(s)?

.......teach me.

Best (and thanks to) all,

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1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia
Old 05-26-2008, 02:07 AM
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Memorial Day bump...............
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Recording Engineer, Administrator and Entrepeneur
Designer of Fine Studios, Tube Amplifier Guru
1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia
Old 05-26-2008, 01:54 PM
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Rx'd a great answer from Pete Zimmerman over on Rennlist...as follows:

Well, this is a tough one - let me try to answer without confusing you further! Loose valves kind of share the same symptom as bad valve guides, but even those two noises aren't exactly the same. When an engine with loose valves warms up it has a tendency to get worse as the oil temp increases; because of incorrect clearance you hear a combination of clicking at the elephants foot along with clacking from the cam/rocker contact surface. Clicking/clacking combine to produce an unhealthy level of noise. Bad valve guide noise is similar, but deeper inside the engine (perhaps more muted), because the valves are moving laterally in their guides. Rocker "noise" is, in my opinion, virtually impossible without additional symptoms. If a rocker cracks it will be a specific failure, with a specific noise - very different from the general noise produced by a sloppy valve adjustment. If a rocker fails because its mounting shaft backs out of position, a miss-fire due to a non-op cylinder will occur, along with an oil leak. If a rocker arm breaks the same symptom will occur - a strong miss-fire from that one cylinder. Now, if you have pitted cams with failing rocker arm contact surfaces, the noise will be exactly the same as loose valves, but if you've done a money shift you will usually have general noise along with poor running (if the engine still runs, that is). I hope that this helps!

Thanks to Pete for his shared time and expertise !!!!

Sounds like she needs to be "heard" by an experts ear.....


Best,

__________________
Recording Engineer, Administrator and Entrepeneur
Designer of Fine Studios, Tube Amplifier Guru
1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia
Old 05-26-2008, 05:29 PM
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