View Full Version : Oil gauge warning on Merc 240 M2.... 02 Islandia

07-02-09, 12:11 AM
Ok gang, first off, I am not an engine mechanic. I can do just about everything else in the world but a mechanic I cannot claim. Neighbor (awesome mechanic) helping solve probs. Oil warning light in fuel gauge went off couple weeks ago. We have filled bottom tank and engine mounted tank is filling....... but slowly. Can't find a leak anywhere yet in any lines, but noticed the line coming off the engine mounted tank a tee. One goes to the engine mounted tank, the other to???? and the third tee has a short line appx 3 inches long that just stops. In the specs, we found two pics, one that shows this tee with a yellow plug in it and another showing it as a vent. Is this supposed to be an "open vent" or is it supposed to be plugged? Seems if it is "open" it would cause air which would screw up the pressurized system???? Maybe....... or not.

Aaron, where are you buddy:cheers:

Supposed to leave Fri am for the lake and can't fathom not having the boat!!!

07-02-09, 12:36 AM
I have same setup on my challenger but it's at storage. I'm guessing, but that one line is probably a vent with check valve. Other line goes to crankcase for a pulse to pressurize system. Check valve would let air in on vacum stroke and close vent on pressure stroke, thus pressurizing system.

07-02-09, 12:47 AM
you may want to loosen the lid on the engine mounted reservoir and run it on the hose till you fill the top tank or till you see it running out of the cap and tighten the cap back to perhaps eliminate any possible bubbles in the line that could be causing the problem.. \
Rookie101 is the Merc guru, he's sure to chime in