Strange Problem with water entering cylinders

A

akisp

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Joined
Sep 5, 2002
RO Number
10052
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36
Ive had this problem for 3 seasons. Just some background. 4 years ago I had the engine replaced with a brand new long block. I have twin Mercrusier engines on my 1997 Cruisers Yacht. One engine was replaced with new longblock. I assume the heads were simply put on from the blown engine. I also had replacement risers and manifolds which I purchased from Boatfix. When I fire up the engine it's hydrolocked. It seems that water enters 1-2 cylinders. If you're facing the engine its the left hand side first and second cylinder, thats were the water comes in.
Last year I took the riser and manifold off and replaced the gaskets, that I thought did the trick. I used it all season with no problem.
Fall I winterized the engines as always. Now the spring comes and I did all the things that needed to be done, waxing, gear oil etc.
Im going in tomorrow Saturday and of course the problem. I took all the plugs and let the 2 cylinders drain (not a lot of water) shot WD40.
My question is any ideas from you folks on what might be causing this?
 
A long block usually means short block and heads. The short block is the block itself with the rotating assembly installed.
If it is hydrolocked it won't fire up. When you crank it you will bend the valves and/or the rod in the hydrolocked cylinder(s) because water won't compress.
What did the oil look like?
Is it running now?
If water is going in to two adjoining cylinders it might be a bad head gasket.
Maybe there was a small leak in the gasket that you might not have noticed because you were running it all last season and it wasn't sitting in the cylinder(s). I would take it apart if I were you and take a closer look inside. Especially if the motor is running now. It would be a shame to ruin a good motor. These things don't get better on their own.
Check the head gasket, and have the head checked for a crack.
But I would be surprised if you didn't have bigger problems than that now from cranking a hydrolocked motor.
 
It would really help to identify everything about your boat. What engine. What type running gear.
Learn Port and Starboard to refer to which side of the boat. Also, V-drives have the engines facing opposite from standard Inboards or I/O's. If you have a GM engine, the cylinders are numbered odd on the engines port side, 1-3-5-7 from front to back and even on the engines starboard side, 2-4-6-8 from front to back.

Otherwise, pretty much what JVM described.
 
Hi its a 1997 Cruisers Yacht. I have twin mercruisers with Bravo !!! drives. The winterization was done as always, that wouldn't be the problem. My other original engine works perfect. As far as the new engine I think the mechanic might have used the old heads. Could it be that during last season the small amount of water was burned out?
Now the engine spins perfect but will not start after I drained the small amount of water.
 
Still haven't said exactly what engines you have. Is it a secret? Also, why was an engine replaced already? What caused it to fail? Could that be happening to the replacement engine also?
 
For an engine to run, it needs fuel and spark. Pull a spark plug and reattach the plug wire. Lay the plug against intake next to the valve cover so it touches ground.
Turn engine over and watch for spark. It'll fire only once every 8 rotations. There are cheapie spark testers that can be attached between coil and coil wire. You will get 8 firings every rotation.

Do you have carb or fuel injection?
 
Some other missing information. Is the engine raw water cooled or fresh water cooled. Is the water in the cylinder raw water or coolant?

If the engine is fresh water cooled (closed circuit) and the water is coolant, then you either have a bad head gasket, the head is warped, or there is a crack in the water galley.

If the water is raw water, then the water is coming back in through the exhaust. Though if it is always the same cylinders, I would lean to a bad head.

To see if the head is bad, look at the coolant overflow while the engine is running. If you see air bubbles in the coolant overflow, then you have a bad head gasket or head. You can also do a compression check on each cylinder. They should all read about the same compression.
 
I have twin 350 Mercruisers with Bravo three drives. Its raw water cooled. The first engine failed due to clogged risers. I only had the boat for a month. I have carburators and electronic ignition.
 
check fuel getting to the car by removing the air cleaner and push throttle and watch for accelerator pump spraying fuel down the primary barrels.

Long block shoulda' come with new heads.
 
An engine does not fail due to clogged risers. It fails because it then overheats. Overheat and reuse of original heads might reinforce the previous comments. Warped or damaged heads. If the water entering the cylinders stuck open exhaust valves then I doubt the engine could start.
As a piston comes up on the compression or exhaust stroke it forces air backwards thru an open stuck valve into the intake manifold and the carb. This in turn affects other cylinders. With a number of cylinders not working properly it will not start. For now I would forget about trying to start it. Fix the water intrusion and any collateral damage first. Once that is complete you may find that it starts.
 
Why are we messing with all these issues instead of checking the water intrusion with a compression check?????
 
The water in two adjoining cylinders leads me to think that the head gasket is bad or the head cracked on the surface between the two cylinders. this was probably a result of overheating.
If it had a small leak from the gasket it may have run for him last season because the small amount of water that was leaking down while the motor ran might have burned off. This is generally easier to tell with cars because you can see the difference in the exhaust and smell the sweet smell of anti-freeze burning off. The car might be OK at idle speeds, but run a bit hotter at highway speeds. It is much harder with a raw water cooled boat because there is a never ending supply of coolant (raw water) and there is no sweet smell of anti-freeze to detect.
It was winterized with raw water sitting in the cylinder(s) which probably locked it up.
He kept cranking it to start it which more than likely bent some valves or a rod or two.
I would start with a compression check, and isf things are as I suspect and those two cylinders are low, I would pull the head on that side.
Chances are good that at the very least the valves are bent and the gasket is bad. Probably a cracked head too.
If he is lucky and the bottom end is still good he might get away with replacing the head and the gasket. Put it all back together and he will be OK. I've seen guys get that lucky before.
If he isn't lucky he will need a new motor.
 
The engine has never overheated last season or now. I had the mechanic put in a new impeller prior to me starting it. I did start it with no problem but no water ever came out. This lasted for a minute or so, then I shut it down. Can the impeller be put in wrong? I always thought that the impeller can be put in and it will correct for the flow due to the rotation.
 
You indicated that the engine was replaced because of a blocked riser. Unless the riser caused some damage why in the world did the engine need replaced other than overheat damage?
 
What is the present problem? Does she turn over?

It's possible to hook up the intake and out hoses backward on the Bravo pump. did she ever start up...and in what chronological order did things happen? (need a refresher)
 
I go with the intake manifold gasket leaking. I had that happen an a 454. If the mechanic that installed the engine did not put extra sealant on those gaskets and really torqued them down right it could very well be your issue too.
 
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