oil blowing out of my dip stick

echobrent

Recruit
Joined
Dec 4, 2005
Messages
1
I have a 1969 mercruser 120 that is blowing oil out of my dip stick.<br />May not be the origional motor, but I got the boat for almost free.<br /><br />Any ideas????
 

Weirdwalt

Petty Officer 3rd Class
Joined
Nov 15, 2005
Messages
77
Re: oil blowing out of my dip stick

Excessive blow by. Now you know why it was (almost) free.
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: oil blowing out of my dip stick

Welcome to iboats! :) Walt is just plain mean.....Probably right, but plain mean ;) You need to do a compression test & see what the numbers say.......Any exhaust coming out of the oil filler on the rocker covers or weird noises?....Again: compression check.....JK
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: oil blowing out of my dip stick

HM, what does exhaust coming out of the oil filler on the rocker covers indicate?
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: oil blowing out of my dip stick

Hole in piston from detonation.....You will hear it, too.....A little steam /smoke is not uncommon, though.....A compression test will tell that....Because it will be 0 #'s.. ;) ...JK
 

Capt Ken

Commander
Joined
Jul 30, 2002
Messages
2,270
Re: oil blowing out of my dip stick

Bear with Walt, the wife probably cut him off again and he's getting a bit edgy.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: oil blowing out of my dip stick

thanks HM, was just curious.....
 

paulie0735

Chief Petty Officer
Joined
Dec 6, 2005
Messages
463
Re: oil blowing out of my dip stick

You might like to check that the inlet manifold is supplying a 'strong' vacuum level at idle to the PVC valve in the rocker cover. If the engine is not venting the negative compression buildup in the crankcase correctly than it will vent it out the dip stick tube along with the oil.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,110
Re: oil blowing out of my dip stick

May not be the origional motor, but I got the boat for almost free.
That's Great,..............<br /><br />Now all you have to do is,........<br /><br />Rebuild the Motor,.......... Or,.. Replace It.......
 

Weirdwalt

Petty Officer 3rd Class
Joined
Nov 15, 2005
Messages
77
Re: oil blowing out of my dip stick

Ya'll have to excuse Ken he's gettin edgy because the thermometer in his back yard has been in the 40's lately. He's gettin ready to call FEMA and head for his emergency shelter. Why just imagine, water might actually freeze!
 

paulie0735

Chief Petty Officer
Joined
Dec 6, 2005
Messages
463
Re: oil blowing out of my dip stick

Yeah, great advise that! You could rebuild the engine or even replace it.............. Or you can check the vacuum port in the inlet manifold and make sure it not just blocked up (35 years of sucking oil fumes down its neck will do that). Also check that the PVC valve is working as it should and that the vacuum line is in good condition and not cracked.<br /> I’m not saying your engine does not need a rebuild, just worth checking a few simple things first.<br /><br />I wonder how many engines have been rebuilt just because they seem to need it!!!!
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: oil blowing out of my dip stick

I dont think that engine used a PCV system but its posible the breather clogged, a leak down test will tell you anything you wish to know about the cylinders sealing ability.<br /> if this is a saltwater motor rebuilding may not be worth it due to internal corrosion.
 

Jilly - 5

Seaman
Joined
Jul 28, 2003
Messages
74
Re: oil blowing out of my dip stick

You don't indicate whether "solid" oil is coming out, or if oil is "spitting" out, or if it's foaming out. Also, what oil pressure gauge readings are you getting? Also, does your engine have your oil in it, or unknown oil from a previous owner? If your oil, what is it? I agree, start simple with a more thorough look at symptoms and facts first.
 

tony_56

Cadet
Joined
Dec 21, 2005
Messages
14
Re: oil blowing out of my dip stick

Another good way to tell is start it and pull the dip stick and put your finger over it, it will tell you alot also, if it sukc and pushs, then you have very serious internal problems but if it only pushes then it might possible only be the pcv like rodbolt said, i know my honda had a pvc, dont know for yours though, you should look it up
 

DTSonnax1

Recruit
Joined
Dec 28, 2005
Messages
2
Re: oil blowing out of my dip stick

The problem is poor crankcase ventilation.Check the vacum ports on the base of the carb/injecter body. :cool:
 

King P.V.

Seaman
Joined
Aug 13, 2005
Messages
72
Re: oil blowing out of my dip stick

Just what exactly are the problems associated with the engine?? Is it hard to start?, won't idle? no power? .............
 

KRS

Banned
Joined
May 15, 2004
Messages
2,383
Re: oil blowing out of my dip stick

Echo welcome! Good news about the boat, not so good about the engine. This however, is the perfect time to start learning about your engine.<br /><br />Read the posts from Haut, Bondo, and Rodbolt, lots of experience in this forum.<br /><br />Good luck, and remember to post an update as you work along. PS.... if you have a picture, post it.
 
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