I have a 454 that was marinized by PCM in my 1989 Supra Saltare ski boat.
Ever since I purchased the boat last year it has been running horribly at
WOT -- this question is about something different however. Stick with me --
it may get long. I'm a complete amateur at this stuff so I'm going to
include everything I can think of and maybe someone can help me.

Beginning the other day the engine exhaust began smelling really bad.
People on the back of the boat were complaining of the exhaust fumes making
them feel sick -- the first time this had happened. Later that day the
engine developed a really loud clicking from the passenger side front of the
engine -- it became much worse as the rpms were increased. It was clear
that it had something to do with the valve-train so me and a buddy took the
headers and valve covers off, and found a rocker arm that was much looser
(had more lash in it?) at DCT. The valves still seemed to be fine, we could
actuate them by hand and they felt correct. The pushrod on that cylinder
was fine. The funny part was that all of the other rocker-arms were
tightened down on the adjustment studs the exact same amount -- to take the
lash out of this noisy rocker-arm I would have to tighten it down 2-3
threads further then any of the others -- this just doesn't seem right to me
that one rocker arm needs to be adjusted tighter then the others.

What would cause this? I've heard that the rocker-arm tightening studs can
begin to pull out and could have to be machined, and I've heard that I may
have had a lifter collapse. What is my next step to try and resolve this
problem?

Thanks for any and all help.

Rob

Robert C. Bosworth wrote:
I have a 454 that was marinized by PCM in my 1989 Supra Saltare ski boat.
Ever since I purchased the boat last year it has been running horribly at
WOT -- this question is about something different however. Stick with me --
it may get long. I'm a complete amateur at this stuff so I'm going to
include everything I can think of and maybe someone can help me.

Beginning the other day the engine exhaust began smelling really bad.
People on the back of the boat were complaining of the exhaust fumes making
them feel sick -- the first time this had happened. Later that day the
engine developed a really loud clicking from the passenger side front of the
engine -- it became much worse as the rpms were increased. It was clear
that it had something to do with the valve-train so me and a buddy took the
headers and valve covers off, and found a rocker arm that was much looser
(had more lash in it?) at DCT. The valves still seemed to be fine, we could
actuate them by hand and they felt correct. The pushrod on that cylinder
was fine. The funny part was that all of the other rocker-arms were
tightened down on the adjustment studs the exact same amount -- to take the
lash out of this noisy rocker-arm I would have to tighten it down 2-3
threads further then any of the others -- this just doesn't seem right to me
that one rocker arm needs to be adjusted tighter then the others.

What would cause this? I've heard that the rocker-arm tightening studs can
begin to pull out and could have to be machined, and I've heard that I may
have had a lifter collapse. What is my next step to try and resolve this
problem?

Thanks for any and all help.

Rob




The "possible" likely explanation given is;

The rocker arm stud/post might be pulling out of the head.

The usual thing is with the engine idling (if possible depends on
install etc) then tighten each arm till it's clicking just stops then
give it another 1/3 of a turn (the hydraulic lifter will absorb this but
not much more for high revs) If it gets lose again after the next
sustained hight revs time, then save any of the more obvious below;
check the stud.

If you have one that's suddenly started making lots of noise it has to
be; sticking valve or spring problem, rocker stud pulling out (as
above), the ball in the rocker is falling to pieces, the pushrod is bent
(from stuck valve??), the hydraulic lifter has gunge in it & isn't
getting full oil flow or the worst is the hardening on the cam has
broken down & the camshaft is dying.


K


& the Krause lie of the day is an oldie but always a giggle, the one
where he sets out his offshore experience just before he got caught in
yet another lie:-)

Glad the grub is back, make ya proud to tell people the left in general
& the union organisers in particular are uneducated lying scum.


Have you ever sailed from San Francisco to Hawaii? I have.
Have you ever rounded Cape Horn? I have, twice.
Have you ever transited the Panama Canal? I have.
Have you owned more than 20 boats in your lifetime? I have.
Have you ever sailed large boats competitively? I have.
Have you ever been hundreds of miles from land in a powerboat
under your command? I have.