I'm almost afraid to ask this question for fear of what answers I might get
but here goes:

My boat has a Volvo Penta 5.7 GS engine (carbureted) with 240 hours on it.
It is very well taken care of. Today as I cranked it up, I let go of the
key before the engine caught on and from the sound of things, I knew what
had happened. The engine actually kicked backwards one stroke and sucked up
some water.

I figured, "no problem, this has happened before and I can handle this." I
took out all of the plugs and cranked the engine to let the water blow out
of the cylinders, dried the plugs and put them back in and proceeded to
start the engine.

The engine started but there was a pretty loud knocking sound. I shut it
down to check my plug connections and to check to make sure I had not mixed
up and plugged the wires back in the wrong order and everything was okay. I
started it once again and still had that darned noise.

Any ideas?

I'm really nervous about this one.

Frank

On Thu, 4 Sep 2003 20:47:12 -0400, "Frank Taylor, Jr."
wrote:

I'm almost afraid to ask this question for fear of what answers I might get
but here goes:

My boat has a Volvo Penta 5.7 GS engine (carbureted) with 240 hours on it.
It is very well taken care of. Today as I cranked it up, I let go of the
key before the engine caught on and from the sound of things, I knew what
had happened. The engine actually kicked backwards one stroke and sucked up
some water.

I figured, "no problem, this has happened before and I can handle this." I
took out all of the plugs and cranked the engine to let the water blow out
of the cylinders, dried the plugs and put them back in and proceeded to
start the engine.

The engine started but there was a pretty loud knocking sound. I shut it
down to check my plug connections and to check to make sure I had not mixed
up and plugged the wires back in the wrong order and everything was okay. I
started it once again and still had that darned noise.

Any ideas?

I'm really nervous about this one.

Frank


Frank, even a small amount of water remaining in the cylinder will
raise hell with your engine. It changes the compression ratio,
drastically, and can cause ring and valve problems. In a "horizontal"
engine, it won't just "blow out" the exhaust.

Hopefully, there is no damage to the piston, rod, or crank. Pull
those plugs again, and check each cylinder for water (with a
flashlight and magnifying glass, if you have to). If you have water
in it, wick it out with cotton rags cut into strips, or cotton rope
(cheap clothesline rope).

If it knocks after this, you have a bigger problem. The hydraulic
lock may have damaged bearings or the crank. (

Good luck.
noah

Frank Taylor, Jr. wrote:
I'm almost afraid to ask this question for fear of what answers I might get
but here goes:

My boat has a Volvo Penta 5.7 GS engine (carbureted) with 240 hours on it.
It is very well taken care of. Today as I cranked it up, I let go of the
key before the engine caught on and from the sound of things, I knew what
had happened. The engine actually kicked backwards one stroke and sucked up
some water.

I figured, "no problem, this has happened before and I can handle this." I
took out all of the plugs and cranked the engine to let the water blow out
of the cylinders, dried the plugs and put them back in and proceeded to
start the engine.

The engine started but there was a pretty loud knocking sound. I shut it
down to check my plug connections and to check to make sure I had not mixed
up and plugged the wires back in the wrong order and everything was okay. I
started it once again and still had that darned noise.

Any ideas?

I'm really nervous about this one.

Frank



Possibly damaged something but it might also just be the valve lifters
not pumping up.

You say you "dried" the plugs what? there was water all through it??
not likely but? The leads are correct?? you say you checked but ....?

Check the oil, is the level right?? not down? or worse up?? If it's up
the water may have been in the engine before you tried to start it &
some has seeped down into the sump, is the oil milky in any way if so
then it has water in it & you'll need to change it & the filter before
you try again. Once you're sure it has clean oil at the right level;

Start it but don't rev it up, if you have an oil pressure gauge/light
after a short time make sure the oil pressure is up , if not turn it
off. The water contaminated oil might have blocked the pickup if it's
been sitting a while, or the milky oil gets thick almost like cream.
Regardless don't persevere if there's no oil pressure because whatever
the trouble it'll only get worse very quickly.

Assuming it has oil pressure & is running as smoothly as a cold carbed
engine does, then give it a little while to see if it is the valve
lifters (they too don't like ANY water in the oil & get stuck taking a
while to come good but with clean oil they will:-))

If after a couple of minutes the knocking is still there, then try to
determine what it is;

(i) Stuck lifters; can cause lots of noise up at the tappets, but it's a
slower rate than you expect (1/2 engine speed) also the noise is at the
top of the engine. Get say 4 ft of garden hose & put one end to your ear
then hold the other end around the engine (be careful, belts & things
are moving), you'll very quickly be able to pinpoint exactly where the
noise is originating. If it is at the very top of the motor & probably
spread over several cyls on both sides, then good news it probably is
just stuck lifters from having some water in the oil. With clean oil &
filter a little heat & they'll probably come right on their own. You
could even risk increasing the revs to "slightly" above idle.

(ii) More serious heavier cluncking noises; Again your hose to the ear
will tell you it's originating below the very top of the engine, it will
probably be localised & it's rate will probably be quite fast. With the
hose you'll at least know which side & end of the engine is the cause.
Then leaving the engine idling, try pulling the spark leads off the
plugs in the suspect area one at a time, till the noise stops (even a
bad thing, given you have oil pressure will be quiet when the plug stops
firing above it). This is now potentially serious so get a compression
tester from an auto parts store (a really cheap one is fine).

(iii) Follow the testers instructions but generally take all the plugs
out, disable the ignition, leave or manually hold the throttle wide open
& crank the engine with the tester in each cyl in turn. Note (as in
write down:-)) the pressures for each cyl. Don't worry about the actual
numbers (particularly with a cheap tester), what you're looking for is a
consistent reading over all the cyls, no more than say a 10% difference
between the highest & lowest. If you get one or an adjacent pair with
very low readings & that/they are the ones you found were causing the
noise, sorry you need to at the very least take that head but better
both heads off & find out what's going on.

K

K Smith wrote:

OOps sorry Frank, I forgot to say that if Tony has any advise different
then definitely go with his, he's pretty damn good!! (the *******:-))


K
..
Frank Taylor, Jr. wrote:

I'm almost afraid to ask this question for fear of what answers I
might get
but here goes:

My boat has a Volvo Penta 5.7 GS engine (carbureted) with 240 hours
on it.
It is very well taken care of. Today as I cranked it up, I let go of the
key before the engine caught on and from the sound of things, I knew what
had happened. The engine actually kicked backwards one stroke and
sucked up
some water.

I figured, "no problem, this has happened before and I can handle
this." I
took out all of the plugs and cranked the engine to let the water blow
out
of the cylinders, dried the plugs and put them back in and proceeded to
start the engine.

The engine started but there was a pretty loud knocking sound. I shut it
down to check my plug connections and to check to make sure I had not
mixed
up and plugged the wires back in the wrong order and everything was
okay. I
started it once again and still had that darned noise.

Any ideas?

I'm really nervous about this one.

Frank



Possibly damaged something but it might also just be the valve
lifters not pumping up.

You say you "dried" the plugs what? there was water all through it??
not likely but? The leads are correct?? you say you checked but ....?

Check the oil, is the level right?? not down? or worse up?? If it's
up the water may have been in the engine before you tried to start it &
some has seeped down into the sump, is the oil milky in any way if so
then it has water in it & you'll need to change it & the filter before
you try again. Once you're sure it has clean oil at the right level;

Start it but don't rev it up, if you have an oil pressure
gauge/light after a short time make sure the oil pressure is up , if not
turn it off. The water contaminated oil might have blocked the pickup if
it's been sitting a while, or the milky oil gets thick almost like
cream. Regardless don't persevere if there's no oil pressure because
whatever the trouble it'll only get worse very quickly.

Assuming it has oil pressure & is running as smoothly as a cold
carbed engine does, then give it a little while to see if it is the
valve lifters (they too don't like ANY water in the oil & get stuck
taking a while to come good but with clean oil they will:-))

If after a couple of minutes the knocking is still there, then try
to determine what it is;

(i) Stuck lifters; can cause lots of noise up at the tappets, but
it's a slower rate than you expect (1/2 engine speed) also the noise is
at the top of the engine. Get say 4 ft of garden hose & put one end to
your ear then hold the other end around the engine (be careful, belts &
things are moving), you'll very quickly be able to pinpoint exactly
where the noise is originating. If it is at the very top of the motor &
probably spread over several cyls on both sides, then good news it
probably is just stuck lifters from having some water in the oil. With
clean oil & filter a little heat & they'll probably come right on their
own. You could even risk increasing the revs to "slightly" above idle.

(ii) More serious heavier cluncking noises; Again your hose to the
ear will tell you it's originating below the very top of the engine, it
will probably be localised & it's rate will probably be quite fast. With
the hose you'll at least know which side & end of the engine is the
cause. Then leaving the engine idling, try pulling the spark leads off
the plugs in the suspect area one at a time, till the noise stops (even
a bad thing, given you have oil pressure will be quiet when the plug
stops firing above it). This is now potentially serious so get a
compression tester from an auto parts store (a really cheap one is fine).

(iii) Follow the testers instructions but generally take all the
plugs out, disable the ignition, leave or manually hold the throttle
wide open & crank the engine with the tester in each cyl in turn. Note
(as in write down:-)) the pressures for each cyl. Don't worry about the
actual numbers (particularly with a cheap tester), what you're looking
for is a consistent reading over all the cyls, no more than say a 10%
difference between the highest & lowest. If you get one or an adjacent
pair with very low readings & that/they are the ones you found were
causing the noise, sorry you need to at the very least take that head
but better both heads off & find out what's going on.

K