Mercruiser MCM 5.7 L totally submerged!

Good morning! Just spent the 4th working through the electrical and mechanical issues on board owing to a fully submerged vessel. The boat is a 1990 Regal 255 XL Ambassador and has a Mercruiser V8 MCM 5.7L block with outdrive. Boat was pulled from the water and sat for 7 days with water in the block. I immediately did the following when received:

1. Drained engine block. Mostly water, some signs of oil.
2. Drained hydraulics (trim tabs, prop trim, power steering pump, etc.).
3. Pulled plugs and coil line.
4. Refilled block with 2 quarts of ATF and 3.5 quarts of 10W-30 oil.
5. Wired up the starter and bumped it to expell remaining water in cylinders.
6. Squeezed some motor oil in the cylinders through the spark plug holes.
7. Bumped engine periodically through the day to expell water.
8. Evaluated electrical system and pumps.

My big concern is obviously the damage to the main bearings and the cyclinders/valves owing to the water infiltration. I am going to change out the oil a second time to see if water is still present/mixing. If the fresh oil does not show the foamy emulsion and further bumping of the engine does not expell more water, would I be safe to put the plugs in and see if it fires up? I can not figure out the cooling mechanism of this engine and can not find a downloadable service manual. Any input at all from others would be greatly appreciated as I don't want to make things worse.

Thanks,

Aaron

Re: Mercruiser MCM 5.7 L totally submerged!

ahickman said:

Good morning! Just spent the 4th working through the electrical and mechanical issues on board owing to a fully submerged vessel. The boat is a 1990 Regal 255 XL Ambassador and has a Mercruiser V8 MCM 5.7L block with outdrive. Boat was pulled from the water and sat for 7 days with water in the block. I immediately did the following when received:

1. Drained engine block. Mostly water, some signs of oil.
2. Drained hydraulics (trim tabs, prop trim, power steering pump, etc.).
3. Pulled plugs and coil line.
4. Refilled block with 2 quarts of ATF and 3.5 quarts of 10W-30 oil.
5. Wired up the starter and bumped it to expell remaining water in cylinders.
6. Squeezed some motor oil in the cylinders through the spark plug holes.
7. Bumped engine periodically through the day to expell water.
8. Evaluated electrical system and pumps.

My big concern is obviously the damage to the main bearings and the cyclinders/valves owing to the water infiltration. I am going to change out the oil a second time to see if water is still present/mixing. If the fresh oil does not show the foamy emulsion and further bumping of the engine does not expell more water, would I be safe to put the plugs in and see if it fires up? I can not figure out the cooling mechanism of this engine and can not find a downloadable service manual. Any input at all from others would be greatly appreciated as I don't want to make things worse.

Thanks,

Aaron

Click to expand...

Ayuh,... Welcome Aboard,.... Saltwater, or Freshwater,..??

Either way, don't worry so much 'bout the oil,...

Fill it with motor oil, 'n get it Lit...

Runnin' it is the Best way to get it dried out, 'n save it...

Re: Mercruiser MCM 5.7 L totally submerged!

Fortunately, it was freshwater. I am hoping for the best in that the engine was full to the brim so to speak with water and the limited contact with air prevent much oxidation.

I am worried that the exaust ports are filled with water and they will be a continued source of water infiltration. Do you have any knowledge about this engine? Any ideas on how to further drain the engine?

Re: Mercruiser MCM 5.7 L totally submerged!

ahickman said:

Fortunately, it was freshwater. I am hoping for the best in that the engine was full to the brim so to speak with water and the limited contact with air prevent much oxidation.

I am worried that the exaust ports are filled with water and they will be a continued source of water infiltration. Do you have any knowledge about this engine? Any ideas on how to further drain the engine?

Click to expand...

Ayuh,... Yes I do,... Get it Started, 'n Runnin'....

The exhaust will or already is blown free...

Re: Mercruiser MCM 5.7 L totally submerged!

Will do!

Re: Mercruiser MCM 5.7 L totally submerged!

Gotta drain the fuel tank. On a car, it is much safer to do. How can I safely remove the water/fuel from the tank? Should I use a hand-cranked pump or can I use an electric pump?

Re: Mercruiser MCM 5.7 L totally submerged!

ahickman said:

Gotta drain the fuel tank. On a car, it is much safer to do. How can I safely remove the water/fuel from the tank? Should I use a hand-cranked pump or can I use an electric pump?

Click to expand...

Ayuh,... Get the motor started on a remote tank,...
'ell, a gallon plastic jug, 'n some fuel line will get it Runnin'...

To clean out the hull's fuel tank,...
I use an electric fuel pump, that I built into a transfer pump, Just for gasoline...

You can suck the fuel out through the pickup tube, or pull the gauge sender, 'n use that hole...

Re: Mercruiser MCM 5.7 L totally submerged!

+1 on getting it running on a separate tank

+1 on sucking out thru the gauge sender unit, that way you can also take a look into the tank.

Re: Mercruiser MCM 5.7 L totally submerged!

Didn't get time enough to clean out the fuel tank last night, but got plugs in and electronics buttoned up enough to spin her around. Had to shoot some fluid down the carb, but got a successful ignition and shut her down for the night! Going to drain the fuel filter and set up a remote tank this evening after it cools down (100+ degrees today) and let it run for a minute or two.

I found part of the manual on line last night that shows me enough of the coolant plumbing to muddle my way through a once-over. What I need help with now is how to set up a temporary water/coolant line to allow me to run the engine for a few minutes. Any suggestions? I know there are muffs that you can buy which allow you to attach your garden hose, but I don't have a store close by. Is there a suggested workaround? Maybe bypass the prop and dislocate the hose on the other side of the transome/gimble?

Re: Mercruiser MCM 5.7 L totally submerged!

ahickman said:

Didn't get time enough to clean out the fuel tank last night, but got plugs in and electronics buttoned up enough to spin her around. Had to shoot some fluid down the carb, but got a successful ignition and shut her down for the night! Going to drain the fuel filter and set up a remote tank this evening after it cools down (100+ degrees today) and let it run for a minute or two.

I found part of the manual on line last night that shows me enough of the coolant plumbing to muddle my way through a once-over. What I need help with now is how to set up a temporary water/coolant line to allow me to run the engine for a few minutes. Any suggestions? I know there are muffs that you can buy which allow you to attach your garden hose, but I don't have a store close by. Is there a suggested workaround? Maybe bypass the prop and dislocate the hose on the other side of the transome/gimble?

Click to expand...

Ayuh,.... At the T-stat housing,... ID the In-comin' line from the outdrive...

Pull it, 'n attach yer garden hose onto that port, 'n go for it...

Re: Mercruiser MCM 5.7 L totally submerged!

If the engine is the same vintage as the hull, I have the manuals you're after....

Engine -> https://docs.google.com/open?id=0B1TAvwZ3TjhfdVNLbWdZMTRQTkE
Drive -> https://docs.google.com/open?id=0B1TAvwZ3TjhfOVRUNEk0anBUR3lQYTkwcUh5RElUQQ

Download and SAVE.....

Chris........

Re: Mercruiser MCM 5.7 L totally submerged!

Please be very careful here.

The muffs supply fresh water needed for your engine and the outdrive. The water pump in the outdrive needs to say wet or will can self destruct in lees than a minute. Can you borrow a set of muffs? You may be able to pull the drive & use a hose on the inlet port but that's more work. Either way make sure the supply is constant or you could create added problems.

Also a few thoughts // Some may be repeats from above but are impotant.

Getting the motor up to temp & flushing the oil repeatedly (2x or more times) as soon as possible should be a primary goal to save the engine.

Trying to siphon fuel from the fuel pickup on the tank does not work well unless the barbed fitting with a check valve is removed from the top of the siphon. Ask me how I know. // The recomendation to pull the sender is probably best as you get to inspect the tank & you can siphon or pump from their as needed.

Re: Mercruiser MCM 5.7 L totally submerged!

I am most gracious to both AChris and Wellcraft-classic210. I had googled for the manuals and only found bits and pieces. Thanks!

Re: Mercruiser MCM 5.7 L totally submerged!

What do ya know, she lives! Got her to turn over and roar. Found a set of muff through a friend of a friend and am going to let it idle for a while tomorrow morning. Also gotta evacuate the power steering pump and put in new fluid.

What RPM is safe with the muffs? Guess I could use the temp guage, but I think it is kaput from H20.

Thanks to all!

Re: Mercruiser MCM 5.7 L totally submerged!

Maximum revs on muffs... about 1500, depending on hose water flow. If you have good strong flow, a little more; low flow, idle...

Re: Mercruiser MCM 5.7 L totally submerged!

Alright, now that it runs, lots of questions about peripheral items:

1. I can't get the engine to run/idle when the remote throttle is in the neutral position. I have to hold push it forward (freewheel, of course) to 1/4 in order to idle at ~900 RPM. Lower unit is in full down position.

2. Blower motor: I don't see one! Looking at the manual now, but was hoping someone would suggest a location to look for.

3. Macerator well: Below the macerator pump, there is a separate well or cavity where the manual valve is located. This well does not drain and I can feel two corners which seem like they have holes/vents through which it would drain. Can anyone tell me where or how this cavity should drain? See picture.



It's freaking hot here (@10:30 AM, 95 degrees and humid) and I am grouchy! Wish I was on the water.

Aaron

Re: Mercruiser MCM 5.7 L totally submerged!

Found the answer to #2. After pulling each of the panel switches down and cleaning out the metal contacts, I turned on the blower and determined its location which was well hidden in the rear transom.

While the panel switches are nice, I would like to replace them with a switch that is more water resistant and perhaps has a shorter, metal lever. These plastic levers are getting brittle and need to be replaced. Anyone suggest a good replacement switch with the same pinout and lighted features?

Re: Mercruiser MCM 5.7 L totally submerged!

what switches do you have?

many switches are Carling

http://www.carlingtech.com/products

you can even buy them pre-packaged on a small panel (for about 3 times it would cost you to go thru digi-key or newark)

Also, nearly all the switches will be IP65 rated (spray down), very very very very few will be IP 67 or higher (submerge up to 1 meter).

how far under the water was the boat?