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View Full Version : water in oil *UPDATE*



Digger
05-14-2002, 07:27 PM
Took the boat out yesterday with my brother. (first time she's been wet since Kentucky, I'm sorry to say) We ran hard for about 2 hrs, mostly over 4,000 rpm, engine hatch open enough so my brother could keep an eye on things. We ran with the oil filler caps off, and the breather tubes off the valve covers displaced away from the air intake. The port engine, the one which had more water, gave off a good bit of steam through the filler cap for about 15-20 minutes, stbd motor just a little. Engines ran like raped apes, no pressure/temp/fluc rpm issues. got back and awhile after shutdown checked the dipstick--no trace of water in either pan. which, needless to say, made me happy. I will keep an eye on it, but my hope is that it was just excess condensation.

Also no oil came out from the dipstick tube (the cracked one on the port motor)or anywhere else. I have a theory concerning this, and a hunch which says the engines are air starved at WOT, which may account for the occasional hiccup in rpm, and may therefore be related to a little oil blowing out from the dipstick tube or from the valve cover vents.(?) Yesterday I kept the hatch cracked open during the whole time. Looking at the air vents on my boat, they really aren't all that big...seems like they should be bigger.

but for now I'm happy as a clam, I may be wrong but I don't think I have a serious issue with water mixing with oil somewhere.

and again, thank you for all your advice and ideas!

took the boat to my mech today. (I have used this mech for a couple years,
he does excellent work and is a straight shooter.) His thoughts:

--it may just be excessive condensation. I seem to get a lot of it. today I twisted off
the oil filler caps and shook about a half a thimble full of water droplets out of each.
--run the boat for an hour or so with the breather hoses disconnected, oil filler cap too
if possible. that will help purge the condensation from the system vice plumb it right back in.
--if the oil gets worse (milkier), or if I notice between oil level checks that the oil level appears
to increase then we will start taking stuff apart. first step remove/inspect oil cooler(s).
then exhaust manifolds. then intake manifold. then head gaskets.

any thoughts on the excessive condensation idea?

CDMA
05-14-2002, 07:30 PM
Well I have some suggestions but I am not supposed to be on the registry so.... :p :p :p

Chris

boldts
05-14-2002, 07:56 PM
I'm no expert, but my 302 Ford engine used to get milky looking oil around the PCV valve and the oil breather. How-ever, when I checked the oil using the dipstick, the oil in the pan was normal. I cleaned the milky oil off the valve cover and didn't notice it coming back. My 18 was stored indoors so the only time I ever saw this type of oil on the valve cover was while camping at a local lake and leaving the boat in the water for the weekend.

I guess it could have been condensation. Does your engine oil have the milky brown color when you look at the oil level with the dipstick? If so, I think there is more to the problem than condensation. If not, this mechanic may be correct and I would follow his next step instructions. Run the engine for an hour and observe the oil level and color in the oil pan.

BTW, when I asked a mechanic to look at my engine at the dealer where the boat is stored, he told me the soonest anyone would have time would be June 11th. I calmly walked out of his office and brought my boat home. On the way home, I stopped at another boat dealer and asked the same question. The mechanic at this dealer, while also being behind in summerizing boats, took it upon himself to at least open the hatch and have me turn the engine over with-out starting it. He saw the sparking and told me what to look at when I got her home and also helped me by telling me where the parts could be found. (It seems that Merc. dealers do not stock tune-up parts) I'm thinking that I need to change where my Donzi is being stored when not in use!

GEOO
05-14-2002, 08:23 PM
Digger, Water will get into the oil if you run cold temps and don't heat up the oil enough 160-200 to get rid of the moisture. My oil was milky after a few runs on the dyno. But no problem after running in KY. GEOO

Murphy
05-14-2002, 08:45 PM
My first thought was oil temp. If the engine temp was too low it probably didn't cook out the condensation. I'm going to remove my oil cooler this season for just that reason.

Murph

Bryan Tuvell 33ZX
05-14-2002, 08:47 PM
DIGGER, I hope you turn out fine.
SCOTT B, the same to you.
A touch of bad luck won't hold you two down.

Keep us posted.
Bryan

BigGrizzly
05-14-2002, 08:48 PM
Digger sounds likethe path I would take. I would be surpised that excessive condensation would only take place in the port engine only , but it could happen. Before you run the engine I would change the oil than check the options. The reason I would change the oil is to get a good handleon it. Just so you Know my Corsican has Positive crankcase ventalation so this condensation thing doesn't happen. The Criterion doesn't have it because of the Blower so it has standard breathers.

Randy

MOP
05-14-2002, 08:59 PM
Hi my two cents, I run only one breather hose to the carb off one valve cover on the other cover I run a mesh breather cap. If you think about it on a tight engine where do you get the air in to displace the moisture and fumes? I have always thiugh two hoses with no inlet was pretty stupid. But what the heck do I know was a marine wrench over 30 years.

MOP
05-14-2002, 09:01 PM
Hi my two cents, I run only one breather hose to the carb off one valve cover on the other cover I run a mesh breather cap. If you think about it on a tight engine where do you get the air in to displace the moisture and fumes? I have always thought two hoses with no inlet was pretty stupid. But what the heck do I know was a marine wrench over 30 years. They don't do dumb stuff like that on your mobile they all have a circulation system as they call it.

Digger
05-14-2002, 09:03 PM
Semper Fi! wink

Rootsy
05-15-2002, 07:22 AM
Just for inspection purposes your mechanic can connect a clear hose to the motor between the intake outlet and the exhaust manifold to look for bubbles in the water which would tell you if you have a head gasket leaking or cracked cylinder head. Actually the procedure used to be right in the merc repair manuals... don't know if they still are these days. heckuva lot easier and cheaper than tearing a motor apart to find out it's not that...

Root

AVickers
05-15-2002, 11:14 AM
Sounds like you may have some blowby going on... There's always some, but you may have one hole that's worse than the others. Don't know how many hours you have on the engines, but sometimes with a relatively new engine the rings haven't fully seated and with an older engine, they don't fully seal...

Anyway, one of the waste products of combustion is H2O -- and some of it ends up right in the crankcase. When the engine doesn't get hot enough for long enough -- a real problem in recreational boats -- it can't cook off the moisture that naturally collects in the crankcase. (I assume you don't have a closed cooling system.) One problem here is that if you run in salt water, you shouldn't go over 140 degrees with the thermostats. Fresh water engines can run hotter -- maybe 160 degree thermostats. A good long run at temperature should cook off water in the system. (One question. Has the engine been started and not run? Periodic, repeated cold starts without bringing things up to temperature will really put some water in the system...)

Anyway, the first thing would be to look for excessive blowby. While the engine is at temperature and idling, pull a valve cover hose or filler cap and watch closely. There might be some little smoke (for lack of a better term) easing its way up from the open hole -- this would be normal. If it "puffs" you've got a bit of blowby -- if the engine is new, run it some more and check it again in a few months. If the engine it old, plan for a rebuild within the next few seasons. This is normal, but bears watching... (There are some crankcase additives that claim to minimize this.)

If you place your hand over it and can feel it huffing periodically, strongly and regularly, then you've probably got a problem. The next step would be to perform a leakdown test on all holes and see emperically what's what... Do this test BEFORE you take a wrench to it.

If you don't have any obvious mechanical problems, run the engines so they spend at least a couple of hours at full operating temperature -- with all the PCV system in tact. This should purge the steam faster than if you just open the hoses. Keep it sealed up and check it again after it's cold. My guess is that you'll see a more nomral situation...

RickR
05-15-2002, 07:02 PM
I like using a Oil TEMP gauge. I figure if the oil temp in the pan is over 225 there wont be any water left in it.
It takes a pretty hard run to get the oil up to that temp on my 95 454 Bravo w/oil cooler and 160 degree thermostat. BTW Water temp remains the same till the oil temp gets up around 270 and then is only goes up a few degrees

RickR
05-16-2002, 08:12 PM
Pre oil cooler rule of thumb is 270 Max.
But if you think about it, the corn oil in your french fryer is 350 so you'd think motor oil could get over 270 without a problem.

When your oil gets very hot it will pre-heat the water going through the cooler and the water temp will start going up.

farmer tx
05-16-2002, 11:02 PM
Digger,

Seems like on the way to Connelley Bottoms, one of your engines "BURPED". Could have had some reversion going on. Agree with Mad Poodle, drain , refill, and keep an eye on it. Good Luck!

Digger
06-03-2002, 11:18 AM
Took the boat out yesterday with my brother. (first time she's been wet since Kentucky, I'm sorry to say) We ran hard for about 2 hrs, mostly over 4,000 rpm, engine hatch open enough so my brother could keep an eye on things. We ran with the oil filler caps off, and the breather tubes off the valve covers displaced away from the air intake. The port engine, the one which had more water, gave off a good bit of steam through the filler cap for about 15-20 minutes, stbd motor just a little. Engines ran like raped apes, no pressure/temp/fluc rpm issues. got back and awhile after shutdown checked the dipstick--no trace of water in either pan. which, needless to say, made me happy. I will keep an eye on it, but my hope is that it was just excess condensation.

Also no oil came out from the dipstick tube (the cracked one on the port motor)or anywhere else. I have a theory concerning this, and a hunch which says the engines are air starved at WOT, which may account for the occasional hiccup in rpm, and may therefore be related to a little oil blowing out from the dipstick tube or from the valve cover vents.(?) Yesterday I kept the hatch cracked open during the whole time. Looking at the air vents on my boat, they really aren't all that big...seems like they should be bigger.

but for now I'm happy as a clam, I may be wrong but I don't think I have a serious issue with water mixing with oil somewhere.

and again, thank you for all your advice and ideas!

ToonaFish
06-03-2002, 01:11 PM
...I'm still snorting over "ran like raped apes."

Anyway, this reminds me, Mark Lazlo created new air vents on his 18 and I never did remember to ask him how it effected Last Tango's performance. Mark?

Bunches

Celene 'off to the beauty supply to unblonde this mess'