3.0 water in cylinders 2 & 3

takemetonegril

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Joined
Jun 25, 2012
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4
Hi folks, I've searched the forums for answer to my problem, but thought I'd throw it out as I'm still a little unsure.

My 1986 Mercruiser 3.0 liter started getting a little water in the 2 & 3 cylinders after the engine was cooled. If I remove the spark plugs, blow out the cylinders it starts and runs smooth as a sewing machine, as always. While it is hot you can shut it down and re-start no problem, let it cool and there's water again.

I've owned it since almost new, it's always been well cared for with no mechanical problems at all for 25 years. Engines never been cracked open. It doesn't have that many hours on it, mostly a one day a weekend boat for 10 trips a year. It does run very well when running even now.

I'm thinking head gasket, although it's never been overheated, maybe underheated as I run it in the ocean (in Maine) and it never develops a lot of heat,
or
cracked head, I see that a lot on here and seemingly a result of running an engine with a blown head gasket, so both
or
a cracked blocked, which usually means the engine won't run for long or water will be squirting out everywhere or filling the crankcase. I hope this isn't the case.

I am going to do a compression test tomorrow, but don't want to tear the engine all to pieces to find out the block is cracked and it's none repairable in the event of an uneven result which I'm sure will be the result of the compression test.

Thank you all for your help
Respect
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: 3.0 water in cylinders 2 & 3

I've owned it since almost new, it's always been well cared for with no mechanical problems at all for 25 years. Engines never been cracked open...

... I run it in the ocean

If the manifolds or risers have never been replaced, then that is the first place to start looking.

By the way - welcome aboard! ;)
 

takemetonegril

Recruit
Joined
Jun 25, 2012
Messages
4
Re: 3.0 water in cylinders 2 & 3

Thanks, a bunch of similar threads came up after I posted this and they all referred to the manifolds and risers. Never occurred to me. I've got a service manual and I'll start reading up.

Thanks for your help
 

takemetonegril

Recruit
Joined
Jun 25, 2012
Messages
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Re: 3.0 water in cylinders 2 & 3

What breed?


It's a Clymers, just read through it, not a lot of help, but it doesn't look like that hard a job if I can get those manifold bolts off.

Any wisdom much appreciated.

Thanks all for the help and warm welcome
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 3.0 water in cylinders 2 & 3

It's a Clymers, ...

:facepalm:... Just what I suspected (hence the question).. Those 'manuals' as a useless as ... well, nothing is that useless... Use it as a kneepad, toilet paper, hand wipes, but it can never be used as a manual....

Download and save these... (they're the Merc ones :D)

Engine service manual -> https://docs.google.com/open?id=0B1TAvwZ3TjhfUVREOHFDUGZRR1NDelg5blYybmNRdw
Drive service manual -> https://docs.google.com/open?id=0B1TAvwZ3TjhfOVRUNEk0anBUR3lQYTkwcUh5RElUQQ

Chris.....
 

takemetonegril

Recruit
Joined
Jun 25, 2012
Messages
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Re: 3.0 water in cylinders 2 & 3

Thanks a lot, that should help for this and a few other jobs as well.
Cheers
Bill
 
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