Broken Valve Spring??
 

Gentlemen,

What would a broken valve spring sound like? Would it make noise at all? Which is more likely to break, the inner or the outer, and which one provides the majority of the holding power for the valve?

I have recently noticed an intermittant rattling, that sounds almost like a playing card being held against a fan. I suppose a clutch could make this noise as well, but I have recently had a new clutch installed as well. I do not trust the integrity of any of this recent work, so don't necessarily bias your suggestions based on these replacements.

There is some history behind this, as I have recently had a bent valve "repaired" after a mechanical overrev. See recent posts from me on excruciating details on the subject.

Any thoughts would be appreciated.

Thanks

------------------
John
70/73 RS Spec Coupe

John,

As far as sounds go, a 'miss' at higher revs, and a 'soft' loss of power at higher revs, too! It is usually an outer spring that breaks, and you should be able to feel a 'looseness,' and maybe see something wrong, at TDC firing point for the cylinder by pressing on the retainer with a dowel or screwdriver.

------------------
Warren Hall
1973 911S Targa

if you can move the valve in with your thumb,(compared to others you can't move) it's got a broken spring. had one a while back that chewed up the top of the valve guide, requiring teardown to fix.it broke the inner one, too. there are "in the car" tools to fix these. patience, a mirror, a magnet and a flashlight req'd. a clatter in the valve cover area at mid to high rpm.