Water on plugs

[mike456]

1992 Mercruiser 5.7L. Bought last year and ran great. Winterized per instuctions including fogging all cyl and draining all plugs and hoses. Changed all bellows, gimble and impleller last month. Started for the first time last Saturday; it turned over in 10 seconds (amazed me). Ran on muffs till 160 t-stat opened. Started and stopped a few times with no issue. Put in river on Sunday and ran briefly with no issue. Went for a one hour cruise on Monday also with no issues. Today I changed the t-stat to 140. The parts guys sold me a 160 in the Fall but I since confrimed 140 is correct to 5.7L raw water cooled. Finished install and tried to start. Turned over for about 5 seconds and stalled. repeated attempts after that failed. I pulled all the plugs and found water in 2 of them (port side aft and port side 3rd from aft). All others looks fine. Oil was new in the Fall and looks fine now (no water in it). Please tell me I don't have a cracked block! Could it be risers, manifold or gaskets? Could it have anything to do with the fact that I ran at 160 on Sunday for an hour? That may be the first time the engine was ever at that temp. As always, thanks for your valuable advice!

 

[bruceb58]

Re: Water on plugs

The temperature is not a problem. Engine would be fine up to 200. Only reason you run cooler with RWC is so that salt doesn't come out of solution.<br /><br />You may not have run it long enough to contaminate the oil but I bet there is water in your oil. Question is..how much! What does the level look like on your dipstick<br /><br />Could be riser/manifold junction. How old are they? You run in salt water? I had a problem where my riser/manifolds failed and got water in my oil. Was very little water so the level didn't rise much.<br /><br />Where I am from, I don't have to worry about freeze damage so someone else is going to have to comment about that.

 

[mike456]

Re: Water on plugs

I saw a recent posting (can't fint it now) with a picture of some rust at the riser - manifold junction. Mine look similar. On Sunday I did tighten all 4 bolts on each riser and they all moved a little bit. Any suggestions on what to try next? Is it worth trying the change the gasket between them? I have no idea about the age of them (they could be original from 1992)but they look fine on the outside. My oil level looks fine but I guess if only a little water got in it may not show. There is definetly no sign of milkly or frothy oil. Should I change it? I do occasionally run in salt water but mostly brakish. Since it was new, the boat was in fresh water lake till last year based on history that I know.

 

[Don S]

Re: Water on plugs

If it's salt water, you better get it out of those cylinder NOW, not tomorrow morning, NOW.... and put some oil in them and spin it over a few times. Even run it without water for a few seconds just to save the cylinders and rings. Impellers are cheap.<br />Your tightening those bolts may have cause the problem if the gaskets and manifolds were on the verge.<br />Overtightening bolts is NOT a good thing. So that should be a practice you should stop.<br />Pull the risers and inspect the surfaces. IF they are not clean shiny metal and NOT a shiny black carbon surface. If it is black, try scraping it with a screwdriver or something and see if you can dig into it. If it is the black carbon, time for new manifolds and risers.<br /><br />

 

[mike456]

Re: Water on plugs

The boat is in the water (fresh water at this point of the river)and I can't easly pull it out. I will pull the riser this moring to see whats going on but I'm concerned about getting the water out of the cylinders. What will happen if I pull the water hose where it connects to the engine? I can let it just pump into the bilge (when I crank the engine) but will water just keep flowing in? Is there any trick on ways to plug it? I'll drain the water plugs on the risers and mainfold first. I have fogging oil from last Fall, should I spray that in the cylinders? Do I need to do all plugs or just the leaking ones?<br />If ther risers are OK I'll have to put new gaskets, do I use gasket cement on them or do they go on dry? Thanks, Don. You are amazingly helpful!!

 

[mike456]

Re: Water on plugs

I sprayed fogging oil into the plug holes but did not crank the engine. Drained engine block, mainfold and riase; then pulled the riser off. It looks OK. No evidence of the black carbon that I can dig into. There is quite a bit of rust on the gasket and the small holes on the fore and aft ends were pretty much plugged solid (I hope that was my problem). I used a paper towel to soak up any remining water in the manifold cavities. Plan is to put new gaskets on both sides today. Can anyone tell me what the torque is on those bolt? I will tighten in a cross patern. Do I need to do anyting else before attempting to start it? Would any remaning water the manifold or cylinders just evaporate as it starts (and I hope it does)?<br />As noted above the oil on dip stick looks fine. Should I be concerned that any water may have gotten in it? Thanks

 

[hullofalottatrouble]

Re: Water on plugs

mike.. change the oil..

 

[mike456]

Re: Water on plugs

I cleaned surfaces of risers and maifolds (seemed fine) changed both riser gaskets and tightend bolts to 25 lbs per my manual. Tried to start it and at first it seemed it would go but then it just cranked with no kick. I tried cranking a few more times but no luck. I pulled the plug that had had the most water in it and found water again. I NOW FEAR THE WORST!. I took the riser off that side to look into the mainfold and it was dry. As noted earlier the oil looks fine with no milkly or frothy evidence. Please tell me there is something else I can try. I have drained the block and fogged the cylinders on that side.

 

[Don S]

Re: Water on plugs

Time to drain the cooling system, block off the water hoses going to the manifold, disconnect the hose for "water in" at the thermostat housing remove the spark plugs and pressurize the system with air. Listen for an air leak.

 

[mike456]

Re: Water on plugs

Don, Is this process trying to find a leak that would be a cracked block or am I listening for a leak in the manifold? Is there anywhere I can find a more detailed description of how to do this? Do I do this on just the side that is leaking or both sides at the same time? Do I remove the spark plugs because I'm listening for leak coming from one of them? At what point would I put air into the system? Sorry for all the questions. You're an amazing resource.

 

[mike456]

Re: Water on plugs

As I read my manual on the cooling system I assume the above pressurize process is to identify a cracked block. Correct? Would I try to put air in at the "water-in" point of the T-stat housing? Also, As I re-read Don's first reponse above (re the riser/manifold) I'm confused about the "shiny metal" comment. Mine was not shiny, it was a greyish color. It definelty was not corroded and I could not dig into to it with a tool. Just wanted to cover all bases and be sure that's not an issue. Thanks again

 

[Bondo]

Re: Water on plugs

The Pressure Testing can be on Any, or All of the Cooling System Compontents,....<br />Individually,... Or Almost All Together,.....<br />It depends on Where you plug What,+ Where you add the Air........

 

[Don S]

Re: Water on plugs

Is this process trying to find a leak that would be a cracked block or am I listening for a leak in the manifold?

You are trying to locate the leak, no matter where/what it is, other than the manifolds. Look at the diagram below.<br /><br />

 

[mike456]

Re: Water on plugs

I'm off to try this this morning. One other question; when I originally pulled the port riser off there was a small puddle (a teaspoon full) of water in the bottom of the manifold. When I pulled it off the second time it was dry. Could that water (the first time) have been pushed out of the cylinder or would it have to have come from the manifold/riser? If its likely the manifold/riser, could it be that the water on the plugs the second time (after I replaced to gaskets) was left over from the original problem? If so how would I get it out of the cylinder before trying to start again? Thank you, thank you, thank you!!

 

[mike456]

Re: Water on plugs

I did the test above and could not find a leak. I hope I was using enough pressure. I blocked the hose ends with wood pegs but it still leaked so I tied the end of a piece of bicycle tube and put that over each and clamped it. Used the valve stem end of the tube to put air in. All of the tube ends filled with air to the point that 2 were about to burst. When I stopped pumping the air did NOT leak out. I listend at the suspect cylinders with plugs out and heard nothing. Would the postion of the piston head at the time of test be a factor? I then ran the air pump into the cylinders to dry out any remaining water. Put it all togather and tried to start. It seemed like it was going to kick over at first but wouldn't. After trying a few times over a minute or 2 I gave up and pulled the suspect plug and it was dry. I hope I've determined that I don't have a cracked block but now I stumped on why it won't kick over. In that past it has ALWAYS started within 15 or 20 seconds. I know I've got fuel in the carb and I'm pretty sure I've got spark. Any suggestions? Could the water in the cylinder have screwed me? It was NOT salt water. Thanks

 

[mike456]

Re: Water on plugs

SUCCCESS!!!!. A fellow boater in the marina had some starting fluid (and some better engine knowledge than me). A few sprays of fluid and some air to the crab and it started. Ran till 140 and idled just fine. Strated and stopped several times with no issue. No its time for a full tune up but I think my problems are solved.<br />As always thanks to Don S (and Bondo). You guys help me sleep at night!!!

 

[hullofalottatrouble]

Re: Water on plugs

mike did you pull all the plugs out and turn the engine over too see if any more water comes out? or anything else for that matter.. sounds like you got it started.. and run so might be a good time to check things out again..

 

[KaGee]

Re: Water on plugs

Glad the engine started.<br /><br />Bet you still have a problem. That water came from somewhere.<br /><br />I pressure tested my manifold till I was blue in the face. It held pressure. I even put some paint thinner in the water jacket and pressurized and it still held pressure and no leakage detected. Put the #$%$# thing back on and water on the plugs again. Started to misfire after about 5 minutes. Put new manifolds on and snap! No more water. Apparently a leak developed internally when the manifold reached operating temps.<br /><br />Only wrote this to let you know in extreme circumstances, a pressure test may be misleading.

 

[mike456]

Re: Water on plugs

Keith,<br />I hope I don't have your problem. When I got it started I ran it for a good 15 minutes at high idle and then at normal. It was at operating temp for most of that time. I had a fellow boater who is a mechanic with me and he listen to it and said it sounded perfect. We shut it down and waited about 5-10 minutes and it started right up. It started fine again about 30 minutes later as I was leaving. I have not been back since but I'll have my fingers crossed when I turn the key next time and when I actual go out for a ride. I'm pretty sure the water came from a bad gasket seal on the riser (and I replaced the gasket). Thanks for the infromation.

 

[hullofalottatrouble]

Re: Water on plugs

Mike,<br /><br />I would recommend that before you turn the key next time you pull out all the plugs and turn it over and see if any water comes out.. it doesnt take much effort to do that.. and the alternative to not doing it could be pretty ugly...<br /><br />ive learned the hard way myself..