Disappearing Oil
 

Ok so I plan a little trip with the wife and kids. Before we head out I check the oil and find its low (not milky just low). I add about 1 quart and off we go. Put the boat in the water, fire it up just fine and take her up to about 45MPH at about 4500RPM only for about a min. The cruise the bay at about 25MPH 3000RPM. When I get the boat out of the water I check the dipstick and its dry. Where has this oil gone???? The bilge is clean no water or oil noticable.

What could this be????:confused:

Should have included that the oil pressure while cruising was about 40 and the oil temp gauge doesnt work. After I got the boat out of the water the engine didnt feel all that hot.

Did it smoke at all while running? I wouldn't think you could burn that much oil without noticing. Doesn't sound good. Bad gasket and/or piston rings.

How long have you owned the boat? Was this your first time on it, or first time to notice the oil issue?

The boat is new to me. It is the third time we have been out on it. No out of the ordinary smoke when running and no drop in oil pressure. No oil in the bilge nor water. She runs very strong (got her up to almost 50MPH). Could it be an oil cooler??? I'm not sure if this engine was so equiped. If it were a gasket, wouldn't the oil be noticable on the engine itself???

I am starting to wonder if I am checking the oil with the boat at a bad angle or not waiting long enough after an outing to let the oil re-accumulate in the pan.

Any help would be greatly appreciated.

Both of those thoughts might be bang on. I've also seen it where an oil & filter change was done & the oil filled to its level on the dipstick but because the oil filter didn't fill until after the boat started running, the amount of oil that was actually in the engine wasn't up to its proper level.

I cant imagine you having 'lost' the oil if there was no evidence of it in the bilge or with some excessive smoking........or, have you noticed any Arabs or Russians hanging around your boat lately? Maybe they've been siphoning the oil and then selling it back to us.... :)

I experienced a similar problem last year. I went out on Lake Erie, and I just had "a hunch" so I checked the dipstick. Bone dry. Took her back in and refilled it. Conveniently it was after an oil change too. Now I always keep a few extra quarts onboard just for refills. The 7.4L burns a little oil, but nowhere near as much as the 502.

Can anybody tell me if the 1995 4.3LX was fitted with an engine oil cooler? I haven't been able to find anything in the Merc manual that would lead me to believe it was. Also, if somebody could attach a picture of it and approx location it would be gretly appreciated. Thinkinh if it has one, it may need replacing (causing the missing oil)

Thanks

I love it when this kinda stuff happens. Sure I look like an idiot, but better an idiot that a $2000 repair. So I pulled the cover off the boat this evening and checked the oil.......guess what. Its over filled. Seems I wasn't waiting long enough after running or the boat wasn't at the correct pich. Overfilled=perfect time for an oil change.

Thanks for the responses guys.

Nah...the 'idiot' label doesn't apply here. Sometimes it's the simplest answer that is the correct one and the hardest one to come up with. ;)

btw...the 4.3 doesn't have a separate oil cooler.

peppe,

Something to keep in mind on the 4.3LX is the dipstick doesn't go all the way into the pan. The oil has to equalize in the dipstick tube to get a proper reading. Cold and thick oil can take several minutes to equalize. I'm glad you found your problem:yes_grin:

~J