On May 4, 2:56*pm, Heimskr wrote:
On May 4, 12:58*pm, wrote:





On May 4, 12:54*pm, wrote:

On May 4, 9:43*am, Heimskr wrote:

On May 3, 1:55*pm, jim78565 wrote:

Heimskr wrote:
Yesterday when I was running it to adjust the idle, before putting it
in the water today :-( , everything was fine then, all of the sudden
quite a bit of black smoke came out and it started blowing steam. Did
I just witness a head gasket letting loose?
I'm really hoping that's the case instead of a cracked head or block.
I checked the oil this morning and it has a green hue with the level
way up, about an inch above full. I didn't bother checking the coolant
as I figure it went up in steam or is currently sitting in the oil
pan.

Thanks

I'm a noob to boat ownership & engine repair/upkeep so please K..I.S.
for S

K.I. real S. You have some problems. Black smoke could mean your tstat
is stuck open. Steam could mean your tstat won't open or the water pump
is toast or a few other things.

Great. Thanks for the K.I. real. I've got a bunch of work to do.- Hide quoted text -

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Before you start taking the engine apart check a few more things.
Once you start disassembling you might lose some information that you
can collect now.

Black smoke is unburned fuel. *That could either mean you have a fuel
delivery problem where you are getting too much fuel. *Or you have a
cylinder/cylinders not firing thus not burning the fuel they do get.
Take a dry and wet compression test of all the cylinders and write
down the numbers. *"Wet" means squirt a little oil thru the plug hole
and crank it a couple times before attaching your compression gauge.
Bad reading dry with good readings wet means a ring problem. *Bad
readings dry and wet is either gasket or valves. *Since it's a rebuilt
engine probably gasket rather than valve.

Steam is not particularly telling if you mean steam out the exhaust.
The water going in to cool the engine is expelled through the exhaust
system and once the engine gets hot it will make some steam because
the water gets dumped into the exhaust where it is pretty hot.

Are you certain of the oil level before you started the engine? *If
the oil level really did rise then I suggest letting some out and
looking to see what is in it. You can pump it out the dipstick but it
would really be better to loosen the drain plug if you can get at it.
If water has gotten into the oil after the engine sits for a bit the
water will be at the bottom of the oil pan. *Water in the oil usually
means a head or intake gasket problem of a crack in the block.

Since you mentioned checking the coolant I'm guessing this is a closed
cooling system with a heat exchanger. *You should check the coolant
for both the level and to see if it has any black scum or oil in it.
A blown head gasket between a cylinder and a cooling passage often
results in carbon residue being forced into the cooling system. *The
engine will suck coolant into the cylinder as well. *On a car this
produces steam. *On a boat you can't tell.

If there does not appear to be any of the above problems then maybe
you have one or more cylinders with an ignition problem or you have a
carb problem. *How old are the ignition and carb? *Did you take them
from the original engine? *Were they working fine then? *How long did
they sit?- Hide quoted text -

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I would also add that on these cast iron V8 blocks it really is pretty
difficult to warp the block or heads. *Particularly if you really got
a marine/truck engine as they have much thicker castings. *If it blew
a head gasket you should use a good metal straight edge and check the
heads and block. *Try to fit a small feeler guage between the straight
edge and the surface. *Planning a head and decking the block are both
fairly inexpensive at your local machine shop. *In the case of the
block you do have to take the engine out of course and that's the big
pain in it.

Well, just for ****s & giggles I decided to fill'er up with coolant
again fire it up and see what happens. There was no coolant in the
engine that I could see once I popped the housing so I couldn't check
for any scum.

Once I fired it up I waited around the stern drive to see what happens
with a close eye on the temp gauge. Once it began to warm up and the
thermostat opened there was dark smoke for about 5 seconds and then
the steam started out of the prop exhaust port, it was kinda dark for
10 or 15 seconds, then it turned white and it did smell like coolant.
Out of the exhaust ports at the base of the stern drive there was
water & coolant pouring out.

The weird part is that before the thermostat opened up the coolant
hoses were nice & soft. There was no steam or anything coming out. I'm
not sure where the oil pressure should be but it was just over 40psi
if I remember right. The temp ran up to about 155 before I shut it
down.

So obviously there is a big problem somewhere.- Hide quoted text -

- Show quoted text -

Bummer. Signs of the coolant in the exhaust are bad. But it may not
be the block. Are your manifolds part of the closed cooling side?

There are two configurations for closed cooling. One is just the
block with the exhaust manifolds and the exhaust risers both being
cooled by the raw water after it leaves the heat exchanger. The other
is the block and exhaust manifold are cooled by the closed side and
only the risers are cooled by the raw water. If you have the second
configuation then your exhaust manifolds could be bad. If you have
the second then it must be a block or engine gasket problem.