Merc 5.7 Water in Oil (Scotland)

cashworth

Cadet
Joined
May 15, 2008
Messages
16
Hi all,

Currently on holiday on Loch Lomond in Scotland and have a similar problem as jtrasap(post below).
We were following my son-in-law's Crownline when his alarm sounded and the engine cut out. It would not turn over on the starter and so I towed him back to the marina where I checked the oil on the dipstick which was ok for both level and colour and now after cooling down the engine turned over and started but was missing on two or three cylinders.
The next day the same symptoms and so suspecting a head gasket I pulled the spark plugs and all four were wet on the starboard bank. I turned the engine over and water was ejected from each plug hole after which I noticed the oil had gone milky and the level had risen a lot.
The boat has 7 hours use this season already and was professionally winterised and so I am suspecting a corroded manifold but how does water get in the sump?
As we are on holiday we have limited tools and all the local mechanics are busy and so we will tow it home in a couple of days but I would like to try to know what's happened before handing it over to the repair shop.

Thanks in advance,

cashworth
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,097
Re: Merc 5.7 Water in Oil (Scotland)

The boat has 7 hours use this season already and was professionally winterised and so I am suspecting a corroded manifold but how does water get in the sump?

Ayuh,.... Welcome Aboard,... I agree with yer diagnosis,...

The water seeped pass the rings over time,...
 

cashworth

Cadet
Joined
May 15, 2008
Messages
16
Re: Merc 5.7 Water in Oil (Scotland)

Hi Bond-o and thanks for the quick reply.

Moving on, how do you prevent this from happening? I have a 2001 Four Winns with a 5.7 PEFC owned from new. It has spent most of its life on its trailer and the rest in fresh and salt water 50/50 and I fitted Volvo;s Neutra Salt anti corrosion system. So do you replace the manifolds at regular intervals or wait for a problem?

cashworth
 
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