Oil resevoir cap air leakage

[JoshRowsky]

I am running a 2007 Merc Opti 150hp. I was on the water and had to put some oil in, and after doing so made a short run when my overheat alarm kicked on. I shut it down immediately and went to go look at my oil level. Thats when I realized the cap was off a thread causing the a breakage in the vacuum. I fixed the lid, and for the rest of the day the engine ran fine, but would not quit smoking. Have I blown a head?

[foolishone]

It may have gone into a self protect mode, extra oil ? I have an Opti but don't know that much about them. If it's blue smoke then it's oil.

[1FASTLASER]

What happened is you caused a lean condition, on one of the cylinders. Hopefully after seating the cap correctly she will clear up. To make sure run a compression test. Easy to do. Pull all the plugs................open the throttle all the way,...................pull the kill switch and then chweck each cylinder. I dont think you hurt anything but it wouldnt hurt to double check. Most likely she just pulled a bunch of oil into the cylinder and at the worst may have stuck the oil ring which a good dose of Seafoam would clear up. Run the compression test and get back to me and I will lead you through the rest.