Water coming out spark plug holes!

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ChrisfromVT

Petty Officer 3rd Class
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Sep 8, 2009
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82
1987 115hp inline 6...

Just changed water pump and the motor fires up and runs nicely but I noticed that water is shooting (at a pretty good rate) from the hole for spark plug # 1 and 6. All the plugs had a bit of milky residue on them like water had gotten on them. The #6 plug looks dry but I haven't checked for spark on that cylinder as I wan't to determine the cause of the water leak first.

Could it just be the water jacket seal?
I've only run this motor on the muffs since I've had it and I was ready for a test run on the lake before noticing this leak. Again, no issues with startup, idle or throttle, just a mess of water coming out around the plugs.
 
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verado7

Chief Petty Officer
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Apr 28, 2009
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Re: Water coming out spark plug holes!

well hopefully its the water jacket - did you change the water pump because of a severe overheat ? at any rate the water jacket will cause those symptoms -if -if your lucky you wont break any bolts during removal -but a leaky gasket will allow water to get sucked into the cylinders ( even past the spark plug threads) - i speak from experience . another place it can happen is the exhaust cover - i personally changed both when i did the water jacket since they are of the same age and when one goes the other will follow .
 
Bob_VT

Bob_VT

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Re: Water coming out spark plug holes!

inline 6? If so that is just a jacket and water will never be able to reach the inside of the cylinder from there....... if it is an inline the exhaust gaskets are where the water in the cylinders start
 
Bob_VT

Bob_VT

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Re: Water coming out spark plug holes!

You can change the gasket for the rear jacket seal but those bolts are notorious for breaking however..... due to the design if you should break a bolt you can access the rear of it and even use a nut and bolt.

There are some old school mechanics that will tell you that you can use silicone and do a temporary fix in the sparkplug holes IMO I would do it the right way and change the gasket before the season is really here.
 
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ChrisfromVT

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Re: Water coming out spark plug holes!

I just bought the motor and thought I'd take some proactive tuneup action, which is why I changed the water pump. The rubber "exhaust leg seal" which sits behind and below the water pump base was slightly damaged, but I don;t think it's an issue.

Bob, you;re saying that if water is reaching the combustion chambers, it's gotta be bad exhaust seals?...and if so, how difficult is it to fix and/or expensive if I decide to have someone else fix it? Should I first try the silicone fix and see if the plugs are still getting wet around the electrodes?
 
Bob_VT

Bob_VT

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Re: Water coming out spark plug holes!

Chris you have a PM
 
A

arsenalpsu

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Dec 1, 2008
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Re: Water coming out spark plug holes!

If you have water on the inside of your plugs that is coming from your exhaust cover, not through the spark plug threads. It MUST be fixed before you run her or you will need to rebuild her. The water coming in from the exhaust cover gets compressed by your piston, which turns it to gas- this extra Oxygen in your gas/oil mix makes the explosion too hot which will melt your piston(s) crown. Your one plug was dry because it's getting steamed cleaned by this water vapor and extra heat, the piston is probably all clean too.

You'll need to pull the block and replace the gaskets, get an OEM book. While you have it apart, replace that rear gasket.
 
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