water in cylinder

[kskal1941]

i have a merc model 1150, 1976, 6 inline. when i pulled the plugs, i found water in the bottom cylinder. i replaced the exhaust manifold baffle cover, the powerhead base gasket and the lower crank bearing cover seals and o-ring. i still have water coming in lower cylinder. i dont want to replace anything else until i know what can cause this, i also looked for cracks while i had the powerhead off, and found none. if anyone cane help id appreciate it. thanks

 

[mulliganmagic]

Re: water in cylinder

Well I hate to brake the news to you, but you might have a blown-up engine. We had a 1978 115 inline 6 and it was ruined by getting water in the gas (most likely from the gas station). So you might want to do a compression test on the bottom cylinder and make sure that your engine is ok.

 

[kskal1941]

Re: water in cylinder

compression on bottom cylinder is 125, same as top and #5, 2 is 130, 3 is 132, and 4 is 130. engine runs fine, but runs rough at idle when warmed up.

 

[WillyBWright]

Re: water in cylinder

I'm betting on a crack in the cylinder, especially if it ever overheated significantly. I refer to these as having eggshell cylinders. Too much heat too quickly and they crack. Not always easy to see, and it won't show up with a compression check. Sounds like you have all the other possibilities covered. Sorry for the bad news.

 

[Clams Canino]

Re: water in cylinder

Ok.<br /><br />When you say you replaced the exhaust manifold baffle cover - do you mean the innermost of the three plates, the one that actually bolts around the ports? In RARE cases THAT one can leak and cause water entry. Note I said RARE cases.<br /><br />When replacing the bottom seals, (the most common cause for water in #6), a good trick is to use THREE seals, all facing lips down and pack grease in and around the seals. That way there the seals will be on new spots on the crank, and you'll have the seals protected a bit by the grease.<br /><br />I dismiss the cracked cylinder pretty much out of hand. Those are steel sleeves cast into the aluminum block. I'm not saying it's impossible, but I've never seen or heard of it yet. Don't even worry about that.<br /><br />Now for the good news!! If when you shut off your inline six hot, it lands with the #6 exhaust ports open, steam will enter #6 EVERY TIME. It's just the way it is and nothing to really worry about.<br /><br />Were it mine - and I just did everything you did - I'd hope for the best and just monitor #6's compression. Since you know how to pull off the powerhead etc etc. The worst you'll ever have to do is to redo some of your work when you replace the #6 piston, asssuming you ever actually have a failure.<br /><br />The feller that lost his from "water in the gas" could have indeed had some water damage issues, but more likely the water caused some strange stuff that lead to detonation and meltdown.<br /><br />I've never seen a total loss of of one of these powerheads unless it throws a rod. Usually one or two pistons die at most. I've repaired SCORES of these powerheads for under $1000 FOB.<br /><br />-W<br /><br />

Originally posted by lapew:<br />i have a merc model 1150, 1976, 6 inline. when i pulled the plugs, i found water in the bottom cylinder. i replaced the exhaust manifold baffle cover, the powerhead base gasket and the lower crank bearing cover seals and o-ring. i still have water coming in lower cylinder. i dont want to replace anything else until i know what can cause this, i also looked for cracks while i had the powerhead off, and found none. if anyone cane help id appreciate it. thanks

 

[WillyBWright]

Re: water in cylinder

Seriously? You've never seen or heard of cracked cylinders on these? I've torn down and seen two four cylinder 650s, an 800, and a 1150 with visible cracks in the casting, all on the exhaust side near the ports, all toward the bottom cylinders. All were overheated, and only one had siezed. The other three ran well except for water in a cylinder after several minutes of running. The sparkplug would stop firing from the water. The original complaints were that one cylinder was cutting out after a few minutes. (The 800 was also just plain wore out.)<br /><br />Addendum...<br />Add a 500 and a 140 to the list. (I didn't work on the 140, it belonged to a coworker. He was hoping we had a block when he started working there.)

 

[Clams Canino]

Re: water in cylinder

Honest to Cod. I've seen **** near 100 of these inline 6's apart and have yet to see a cracked cylinder. I must have done 30 this past summr alone. No kidding.<br /><br />I can't speak to the 650 or 800 4 cylinder, but I've never seen a 6 with a cracked cylinder.<br /><br />I'm curious though, as to exactly what you mean by "cracked cylinder" in regards to the six. Are you speaking of a crack that starts under that inner water jacet cover on one of the three "pads" of aluminum around the actual port holes? Do these cracks extend through to and also crack the steel sleeve?<br /><br />I have seen ONE with some cracking around this pad, I had it welded up and milled back to flat and then replaced the innermost plate. I called that "heat cracks around the ports causing water to enter" as opposed to a "cracked cylinder".<br /><br />By the way if someone else is reading this, you *never* wanna pull that innermost plate that covers around the ports unless you are SURE it's leaking. Expect at least 5 (out of the 21) broken bolts, a new helicoil hobby, and a day of gasket scraping. A bad day.<br /><br />-W<br /><br />

Originally posted by WillyBWright:<br />Seriously? You've never seen or heard of cracked cylinders on these? I've torn down and seen two four cylinder 650s, an 800, and a 1150 with visible cracks in the casting, all on the exhaust side near the ports, all toward the bottom cylinders. All were overheated, and only one had siezed. The other three ran well except for water in a cylinder after several minutes of running. The sparkplug would stop firing from the water. The original complaints were that one cylinder was cutting out after a few minutes. (The 800 was also just plain wore out.)<br /><br />Addendum...<br />Add a 500 and a 140 to the list. (I didn't work on the 140, it belonged to a coworker. He was hoping we had a block when he started working there.)

 

[WillyBWright]

Re: water in cylinder

The cracks were in the aluminum castings only as I recall. They extended down from one exhaust port toward the crankcase. At least one had cracks extending between 2 or 3 ports as well. The 140 might have had a crack in the sleeve as well. I seem to recall that it did. The other cracks were hairline, but the 140 aluminum casting crack had a gap. My coworker saw the 1150 block in the shed and wanted to use it for his 140. Which leads me to a question for you. Had that block been good, could he have used his 140 parts and ended-up with a working 140? I never looked into it because the crack made it pointless.<br /><br />The 500 was completely shot anyhow and the customer didn't want to pay for a teardown, but it had all the same symptoms. I'll withdraw that one since I never actually confirmed it with a teardown.

 

[Clams Canino]

Re: water in cylinder

Ok, on those cracks - I've seen that once, and had it fixed as the sleeve was not impacted.<br /><br />As for interchangabilty: here's the scoop.<br /><br />In 1970 and 1971 the 135 and 115 used the same EVERYTHING except for reed stops. They strangled it by letting the 115 reeds only open about 1/2 as much. So that was an easy conversion.<br /><br />Starting in 1972 with the 140 (when the blocks started getting painted black) it was done with port sizing, so none of the black 115's can become 140 / 150's.<br /><br />In 1973 they added the boost port on the side of the piston and the finger port in the sleeve. The 140 became the 150.<br /><br />Then, when the V6 150 came out (78?), they renamed the inline 150 a 140, so as not to have 2 150's competing. ALL that changed was the stickers. Marketing move. The only "true" 140 is the 1972 with the big ports and no boost port.<br /><br />Lastly, in 1982 they went to "propshaft ratings" the 115 with the small ports became the 90 and the 140 became the 115.<br /><br />So other than the '70 and '71 115/135's, the blocks were very different. In my mind I call them "small block" and "big block" (to describe the ports) as opposed to the HP ratings - which varied with the marketing departments needs.<br /><br />Got it now?? LOL!!<br /><br />-W<br /><br />

Originally posted by WillyBWright:<br /> Which leads me to a question for you. Had that block been good, could he have used his 140 parts and ended-up with a working 140? I never looked into it because the crack made it pointless.<br /><br />The 500 was completely shot anyhow and the customer didn't want to pay for a teardown, but it had all the same symptoms. I'll withdraw that one since I never actually confirmed it with a teardown.[/QB]

 

[WillyBWright]

Re: water in cylinder

Good info. I jotted it down. Thanks.<br /><br />Addendum:<br />I could never figure out how a crack on the exhaust side could cause water to get into the cylinder without a crack in the sleeve. There is no pressurized water there. I puzzled and puzzled over that for years and nobody I asked could provide an explanation. Finally it dawned on me. It doesn't leak into the cylinder. It's getting into the crankcase and ending-up in the cylinder. Exhaust pressure is forcing it in AND it's being sucked in as the piston draws the fuel/air mixture. Remember that the cracks extended from the exhaust ports toward the crankcase. It's the crankcase end of the crack that's providing the path. And maybe a bit of leaching between the aluminum casting and the sleeve. The water is coming as spray from the exhaust as it exits the block, not from the pressurized water jacketed area.

 

[kskal1941]

Re: water in cylinder

so what am i looking for? a crack in th exhaust side of the block, or the intake side, or something else? i started and ran with #6 plug out and it blew water out the spark plug hole as soon as it started, water was supplied by muff.

 

[Clams Canino]

Re: water in cylinder

You're looking for trouble on the exhaust side. <br /><br />OR the lower seals... <br /><br />You can get the lower end cap out without splitting the powerhead - but be carefull not to break the 3 ears. Use the correct puller if you can. Put THREE seals in the endcap and use grease between them all. ($28)<br /><br />On the exhaust side. Remove the side covers and replace the middle one if it's at all perforated. Scraping the gasket surfaces will take a morning.<br /><br />If you don't see an obvious problem there. You'll have to pull the inner plate around the ports. Given the nature of your problem and it being that far apart - you might as well.<br /><br />Take your time on the 23 bolts that hold on the innermost plate. An impact wrench set to a low torque can help vibrate them out. If you break any, have someone weld a SS nut on the remainder, and then tap them side to side a bit with a hammer and penitrating oil. Be carefull not to marr the mating surface. You can usually get the bad ones out this way. Failing that it's time to drill them out and use a 5/16 18 helicoil kit. DO NOT drill too deep and go into a cylinder!!!<br /><br />Inspect the exhaust ports for any cracking, use a new innermost plate ($75) and a new Mercury gasket. Use a light coat of RED permatex on the innermost plate surfaces. Torque it to 200 inch pounds in the pattern shown in the manual - do it in three steps. Use a light coat black permatex on the two outer plate gaskets. Do not re-torque the plates once it's done once. <br /><br />Make sure the exhaust baffle surface where the middle plate hits the inner plate is clean so it don't hang it up.<br /><br />If you remove the innermost plate - stuff little balls of paper towel in the ports to stop crap from getting in there too.<br /><br />Welcome to my nightmare.......... <br /><br />-W<br /><br />

Originally posted by lapew:<br />so what am i looking for? a crack in th exhaust side of the block, or the intake side, or something else? i started and ran with #6 plug out and it blew water out the spark plug hole as soon as it started, water was supplied by muff.

 

[Clams Canino]

Re: water in cylinder

If it makes you feel any better, the very next block on my bench tomorrow morning is a 1979 140 that died of water entry issues. <br /><br />I'm looking forward to it about as much as I'd look forward to a root canal.<br /><br />You are not alone..... <br /><br />-W

 

[Clams Canino]

Re: water in cylinder

QUOTE: Make sure the exhaust baffle surface where the middle plate hits the inner plate is clean so it don't hang it up.<br /><br />Note: this is important. Check the clearnace with no gasket 1st - it should not rock backand forth or BARELY rock. File it a little if needed. Use red permatex on that surface if you want to.<br /><br />If that surface is too high, it can slightly warp that middle plate and cause internal leaking too.<br /><br />-W

 

[Clams Canino]

Re: water in cylinder

Just a follow up. The lower seals were shot. It sucked water into #6, which now has to go .015 over because he ran it till it died. The lower bearing is also toast. I also pulled all three exhaust plates - no apparant leak. <br /><br />-W<br /> <br /><br />

Originally posted by Clams Canino:<br />[QB]If it makes you feel any better, the very next block on my bench tomorrow morning is a 1979 140 that died of water entry issues. <br /><br />I'm looking forward to it about as much as I'd look forward to a root canal.