[Healeys] intermittant engine clatter

[Michael Salter]

Hi Steve,
I would certainly agree with Norman that you don't drive it until you have
found out what the problem is.
>"Engine speed-linked. Interestingly it sped up and became lighter when I
>took my foot off the gas."
The only thing that I have ever experienced that gave that symptom was a
broken piston. My theory is that when there was no compression on the piston
it was subjected to an unloaded condition at the top of the stroke on every
revolution but when there was a power stroke it produced a much louder noise
from the damaged piston on every combustion stroke.
I would do a compression test then take a careful look at the ends of the
spark plugs and peer down each spark plug hole with the piston at the top
you may see some impact damage on a piston. 
While you have the plugs out turn the engine by hand on the fan to see if
there is a tight spot.
Also if you can have it idle while it is making the noise try shorting out
or disconnecting the plugs one at a time to see if there is a distinct
change. 
As always I would do as much as you can to diagnose the problem before you
take things apart...it usually pays off.

Michael Salter
100 (1953)
AHX12 (1953)
Bugeye (1961)
http://www.netbug.net/blogmichael/

-----Original Message-----
From: healeys-bounces+msalter=precisionsportscar.com at autox.team.net
[mailto:healeys-bounces+msalter=precisionsportscar.com at autox.team.net] On
Behalf Of Steve B. Gerow
Sent: May 17, 2008 1:55 PM
To: Healeys Newsgroup
Subject: [Healeys] intermittant engine clatter

Today my engine just started making a very loud intermittent clatter.

Happened at startup when cold, went away after around 20 sec running.

After a couple of 10 mile drives with stops, clatter returned on 190 degree
engine. Engine speed-linked. Interestingly it sped up and became lighter
when I took my foot off the gas.

With the car stopped, it seemed to be coming from the area of #2 cyl's
valves. After a couple of minutes it went away again smooth as silk. Then
returned after a short distance. Came and went during 5 mile drive home.

Oil pressure normal around 35 lbs same as it's been for years.
Later checked oil 1/2 way up dipstick.

No fan, water pump or generator irregularities or interference. No over
heating or missing or rough running except for this extremely loud clatter
which I could feel coming thru the car, slightly. No smoking.

On removal of valve cover only evident irregularity was foot-tall geyser of
oil off one of #5 cyl's rockers.

Appreciate any guidance! Thanks in advance.
-- 
Steve Gerow
Pasadena CA
59 BN6--29D engine