low oil

[luisito]

i have 1968 120hp, 153cid, 2.5L Mercruiser and went i check the oil was ok then i take to the bay above 35 min. off shore then the lifter sound little bit and in the way back 35 min. more run fine but at the dock i notice the lifter soundig again i get the boat out and go home for the day but went i was washing the boat i check the oil and needs above 2 qts i using what mercruiser recomend 25/40 oil.<br /><br />what do you think.....?

 

[andrewgroup]

Re: low oil

The oil has to go somewhere.<br /><br />Was it smoking terribly?<br />Is the bilge full of oil?<br /><br />that seems like a lot of oil in such a short time. I would do the same test again, only on the driveway with the hose hooked up.

 

[luisito]

Re: low oil

no smoke and the bilge is clean and dry unless the eng. was not completed level went i do the ck the oil first time; and is not oil mix with the water sys. i goin fishing to the same place on saturday i goin to be shure tha the boat is level and the oil is at the line.<br /><br />i forget to mention that went the lifter start sounding the pressure lower from 40 to 20

 

[luisito]

Re: low oil

I do a second test. I drive 12 miles at 3500 rpm speed (20 mph GPS) then i stop the engine because lifter start sounding and when i check the oil was 1/4 and 1/2 low put some oil on and drive back 12 miles to the shore at 3500 rpm (20 mph GPS) when i get to shore take the boat out check the oil and was 1/4 and 1/2 low.<br /><br />1) no oil on the bilge<br />2) no oil thru the exaust<br />3) no smoke thru exaust<br />4) where the oil go.<br /><br />oil pressure full of oil 40/45 <br /><br />Q. what is the normal speed WOT on this boat aristocraft 1968 19 ft 4cil 120hp 153cid or max rpm on this eng.

 

[loadnet]

Re: low oil

Luis - the oil has to be going out the exhaust..if you don't see anything in the bildge.<br /><br />You may not be able to see it with all the steam action going on back there..<br /><br />Sounds like you have worn rod bearings, main bearings or camshaft bushings causing your oil pressure to drop once the engine gets a little heated up..<br /><br />After you run the engine a little bit pull the dip stick out and smell the oil on it.. and see if it smells like gas.<br /><br />Hold the dip stick in the down position away from your face and try to light it with a lighter and see if it flames up or crackles and kinda sparks like it's trying to light on fire..<br /><br />If so, you are getting fuel in the oil base which will REALLY cause the oil to break down and loss of pressure.<br /><br />I probably shouldn't assume but I am assuming you have hydraulic lifters in that engine that are collapsing on you.<br /><br />Just my opinion.

 

[luisito]

Re: low oil

the oil pressure go down and the lifter sound when the oil level drop one qt and i think has to be some sign of oil thru the exaust if the eng. burn oil.?

 

[loadnet]

Re: low oil

Remove the exhaust outlet hoses and see if you have a serious build up of carbon in there.<br /><br />Remove the plugs and see if they are oil fouled.<br /><br />If you do find one or the other or BOTH of the above your engine is burning oil.<br /><br />But before you rip her down check your pcv to make sure it's not clogged..<br /><br />If your engine can't breath it'll consume oil.

 

[luisito]

Re: low oil

i check the plugs, boot,pvc and they are fine what i find was some oil on the water hoses and in the valve cover filler cap was mugy i was thinking above small crack in a cilinder block (no water in the oil pan) i don't have oil cooler sys i goin to do a compression test this weekend<br />what do you think.? <br /><br />i also check with the match to light the oil and was neg.