Water in Cylinders Part II

ThndrSki

ThndrSki

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May 27, 2011
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So I posted here before about finding water in my cylinders on my 5.7L Magnum '95. I pulled the risers and manifolds and they were definitely in desperate need of replacement/attention. I replaced them with OEM Mercruiser manifolds, risers and gaskets.

I thought this was the issue, but I took my boat out to the lake today, ran it for about 10 minutes, slowed down to neutral, let it idle for 1 minute and it dieseled one time and shut off. It was so fast I couldn't even turn the key back to the on position.

Went to start it back up and bzzzzzzzzzrrrrrr, the starter just free wheels in the housing. No clank, nothing.

Get towed back to the ramp and there is water just in the starboard side (again), port was dry as a bone.

Now after dropping 1k on manifolds and risers, what is the issue. Could the one diesel suck water up or am I potentially looking at a cracked block/head? The boat runs like a scalded dog when it is running. That's what I can't figure out...

Getting to the end of my rope as I have plenty of experience with cars and trucks, but this thing has been a lemon for me. Timing is dead on 8 degrees BTDC, new plugs, gapped right, (AC Delcos, what the FSM calls for) etc.

Thoughts?

Edit: I also wanted to note that I have only found water in the starboard side. Ever.
 
bruceb58

bruceb58

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Re: Water in Cylinders Part II

The dieselling caused the water to get sucked in.

How hot is the engine running? Try running the engine with the engine hatch open and the blower on to keep the engine cooler before you turn it off as an experiment.
 
D

dingdongs

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Re: Water in Cylinders Part II

are the flaps in the y manifold as the dieseling gulped water in and they may have helped.are you sure you have the correct plugs and the timing is good.
 
tpenfield

tpenfield

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Re: Water in Cylinders Part II

ThndrSki said:
So I posted here before about finding water in my cylinders on my 5.7L Magnum '95. I pulled the risers and manifolds and they were definitely in desperate need of replacement/attention. I replaced them with OEM Mercruiser manifolds, risers and gaskets.

I thought this was the issue, but I took my boat out to the lake today, ran it for about 10 minutes, slowed down to neutral, let it idle for 1 minute and it dieseled one time and shut off. It was so fast I couldn't even turn the key back to the on position.

Went to start it back up and bzzzzzzzzzrrrrrr, the starter just free wheels in the housing. No clank, nothing.

Get towed back to the ramp and there is water just in the starboard side (again), port was dry as a bone.

Now after dropping 1k on manifolds and risers, what is the issue. Could the one diesel suck water up or am I potentially looking at a cracked block/head? The boat runs like a scalded dog when it is running. That's what I can't figure out...

Getting to the end of my rope as I have plenty of experience with cars and trucks, but this thing has been a lemon for me. Timing is dead on 8 degrees BTDC, new plugs, gapped right, (AC Delcos, what the FSM calls for) etc.

Thoughts?

Edit: I also wanted to note that I have only found water in the starboard side. Ever.
Click to expand...

Did I tell you about the time the cylinder head on my 454 rotted through and filled the port side cylinders with water?? I too got the 'standard answers' of manifold issues etc., which was actually not the real problem; even though the manifolds were in need of replacement.

So, maybe (just maybe) the starboard side cylinder head is having issues and providing the source of the water. Your best bet would be to perform a pressure test on the cooling system and listen for where the air is leaking. You can also do the compression test and cylinder leak test to get an assessment of the engine's condition as it may have hydro-lock damage at this point.
 
ThndrSki

ThndrSki

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Messages
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Re: Water in Cylinders Part II

bruceb58 said:
The dieselling caused the water to get sucked in.

How hot is the engine running? Try running the engine with the engine hatch open and the blower on to keep the engine cooler before you turn it off as an experiment.
Click to expand...
The engine runs spot on 150 all the time. I had just dropped the lower unit, replaced the water impeller and changed the gear oil... Everything is spot on in the temp department.

You think it did? I only found water on the starboard side. Wouldn't there be water in both if that was the case?

dingdongs said:
are the flaps in the y manifold as the dieseling gulped water in and they may have helped.are you sure you have the correct plugs and the timing is good.
Click to expand...

I have through hull exhaust, and yes there are flaps on the openings of the exhaust pipes. It also leads me to believe that it couldn't have been the one "diesel" cycle as the exhaust was not fully submerged. I think it would have a difficult time sucking water up the exhaust this way. Timing is correct at 8 degrees BTDC.

tpenfield said:
Did I tell you about the time the cylinder head on my 454 rotted through and filled the port side cylinders with water?? I too got the 'standard answers' of manifold issues etc., which was actually not the real problem; even though the manifolds were in need of replacement.

So, maybe (just maybe) the starboard side cylinder head is having issues and providing the source of the water. Your best bet would be to perform a pressure test on the cooling system and listen for where the air is leaking. You can also do the compression test and cylinder leak test to get an assessment of the engine's condition as it may have hydro-lock damage at this point.
Click to expand...

Yeah, I'm starting to think I'm having a problem with a block or cylinder head on the starboard side. It has only happened on one side and I need to figure out how to check it out.

Are you speaking of running a cylinder leak down test to see if there is a crack/something not seating right?
 
tpenfield

tpenfield

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Re: Water in Cylinders Part II

I would also do a pressure test of the cooling system. this is a bit more tricky, but it would take a lot of the guesswork out of finding the problem.
 
Dshow

Dshow

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Re: Water in Cylinders Part II

How would you do a pressure test on a raw water cooled engine? Do they make adapters that would block off both risers and then some for of adapter to pressurize the raw water input to the engine?
 
bruceb58

bruceb58

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Re: Water in Cylinders Part II

You don't pressurize the exhaust portion. Just the engine.
 
H

HT32BSX115

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Re: Water in Cylinders Part II

Dshow said:
How would you do a pressure test on a raw water cooled engine? Do they make adapters that would block off both risers and then some for of adapter to pressurize the raw water input to the engine?
Click to expand...

Imagine the engine is a pressure tank with more than a few openings.

1. disconnect the exhaust manifolds/risers (because you cannot close off the raw water output on a riser)

2. close off all the raw water openings except 1 on the block with any suitable plumbing plugs, fittings and hoses.

3. connect a valve to the remaining opening with a gage on the engine side (of the air shut-off valve) and a quick disconnect (for your compressor air hose) on the other side (of the valve).

4. Hook up your compressor and pressurize the block to about 15 psi or so.

5. Close the valve (and turn the compressor off so you can hear)

The gage should stay at 15 psi.

If it doesn't...........
HOUSTON..........WE HAVE A LEAK!
Click to expand...


If it's on the outside, use soapy water to look for bubbles.



If it's on the inside......listen for the leak in the oil fill.


gud luk!

Rick
 
tpenfield

tpenfield

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Re: Water in Cylinders Part II

Dshow said:
How would you do a pressure test on a raw water cooled engine? Do they make adapters that would block off both risers and then some for of adapter to pressurize the raw water input to the engine?
Click to expand...

Just to add to what has been posted already . . .

Follow the water through the engine . . . It comes in via one hose and typically exits via 4 hoses leading to the exhaust manifols/elbows. It is not practical to test the manifolds in this way, so just disconnect and plug the 4 hoses leading to the manifolds, etc.

then you apply pressure to the one hose where the water normally enters, the system is now 'pressurized'.

I would take the spark plugs out so you can hear things better, and make sure you have decent access to listen to the intake manifold, etc.

Once you apply pressure to the 'system' you are then looking for water and or air to escape. there should be none . . . but where there is . . . that is your leak and the source of the water getting into the pistons, etc.
 
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