Oil leak?

SPOONMAN1

Petty Officer 2nd Class
Joined
Aug 19, 2008
Messages
177
I have a 2001 Mariah with a a 3 year old replacement 5.7 Mag (merc with 50 hrs) and an Alpha 1 out drive. This is the second season I have had the boat, no issues last year. My 20 yr old has been running it at the lake this year, I haven't been out. (workin OT). Anyway I noticed the grass under the drain hole was dead where it was parked in the yard, further inspection reveiled there was oil in the bilge and also on the motr mount on the drivers. The dipstick showed more than a quart low. No harm, no foul it has vortec heads and he said the bolts were tight. I told him to replace the valve cover gasket. When he got the cover off, gasket looked good I anm thinking maybe the dipstick was not all the way in and it pushed out??????? I dont know.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: Oil leak?

Before you start throwing a bunch of parts at it, why don't you clean things off nice and clean and go for a test run and find out what's leaking for sure, then fix that.
 

SPOONMAN1

Petty Officer 2nd Class
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Aug 19, 2008
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177
Re: Oil leak?

My 20 yr old son as referred to in OP.We did power wash the block and ran the engine with muffs in the yard, with little success due to low RPM and very difficult to see because of exhaust manifold and tight quaters (again I am not there because of work, so he-my son did this. Anyway is it common for an engine to have enough crankcase pressure to push oil out of the dipstick?
 

RogersJetboat454

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Jul 9, 2010
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2,964
Re: Oil leak?

Anyway is it common for an engine to have enough crankcase pressure to push oil out of the dipstick?

Yeah, if the PCV system is restricted.

Another diagnostic aid if you really aren't sure about a leak's location is oil dye. NAPA, and other reputable auto parts stores sell it. You will need a UV light to see it, and some of those yellow lensed safety glasses. But it works good for pinpointing the source of a leak.
 

Bondo

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Apr 17, 2002
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70,939
Re: Oil leak?

My 20 yr old son as referred to in OP.We did power wash the block and ran the engine with muffs in the yard, with little success due to low RPM and very difficult to see because of exhaust manifold and tight quaters (again I am not there because of work, so he-my son did this. Anyway is it common for an engine to have enough crankcase pressure to push oil out of the dipstick?

Ayuh,.... A digital camera will give ya a set of eyes, Anywhere you can reach yer hand,....
Not that, that's Easy on a boat, it Can be done,... just plan on removin' extra "Stuff",....

Oil, like water, flows Downhill,....
Only the belts, 'n pulleys can throw oil on a boat motor, no fan,...
Look for the Shiniest oil, then look Up, the leak is at the top of the Shiniest oil,....
 

SPOONMAN1

Petty Officer 2nd Class
Joined
Aug 19, 2008
Messages
177
Re: Oil leak?

OK, I am still working 7 days a week 14 hrs a day, so I am unable to particpate with my 20 yr old sons follies with this boat. He changed the drivers side valve cover gasket, tested it out on muffs with low RPM, no leaks. Then took the boat out to the lake, drove it a short time with friends, slopped checked everything -good(no leaks no oil loss. repeated - good. a very short time later he caught the loss of oil pressure on the gauge and shut it down, raised the cover to find oil dripping from everywhere. I suspect the front seal has given it up. My quetsion is why was this intermitten and why would the crankcase have so much pressure?
The rest of the story is after being towed to the ramp, and being worried dad was going to kill him he pulled the boat to the ramp with another boat and with our 1 ton 4 dr dually pulled it up the ramp, when the screams of his friends got his attention (out drive still down) he shut off the truck went to the remote trim control and raised the outdrive enough to allow the truck (evidently left out of gear and E brake old and weak) to roll down the ramp, he ran up the ramp the truck was rolling down the ramp when he met the open drivers door at a good enough clip to give him a concussion. The truck did not roll over him but did go into the lake to where the only part not submerged was the engine. After the ER trip and retrieving the truck and boat from the lake I got 0 hours sleep that night.
Oh yea The skeg is bent to a total 180 looking up.Where does that post go?
 

SPOONMAN1

Petty Officer 2nd Class
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Aug 19, 2008
Messages
177
Re: Oil leak?

The PCV valve was non exsistent when we took it out and bought one and installed it prior to him taking it to the lake this time.
 

SPOONMAN1

Petty Officer 2nd Class
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Aug 19, 2008
Messages
177
Re: Oil leak?

Good question. I havent been out this year but last year it just seemed normal. My son says 70 psi
 

SPOONMAN1

Petty Officer 2nd Class
Joined
Aug 19, 2008
Messages
177
Re: Oil leak?

First day off. power washed engine, topped off with oil , on muffs, ran for 1/2 hr at about 2700 rpm, found drip on the front oil pan gaket at the bootom of front radious onder the harmonic balancer. can't tell if it is running down from seal or if it is the op gasket. Dont want to pull engine of course but I don't want to fight a new gasket under the engine so I am hoping it is the seal. going back to keep looking. Temp 175-- oil pressure 70 psi.
 
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