1999 Merc EFI 175 - oil everywhere pls help!

[Ken Paydon]

I hope someone can help with my peace of mind... I have a 99 Viper Coral F&S with a 175 EFI Merc. The family & I had a full day out on the water, logged several miles/ hours with no mishaps (except mid-day, there was an unexplained stall as we were trying to get on plane after having been beached for lunch). I put the boat on the trailer, drove to the campsite, and within 5 minutes the splashwell was full of oil!<br />It was dark by this time, so after a sleepless night I peaked around under the cowling and there obviously was oil everywhere. I was suspecting the fill cap to the remote oil tank may have been loose? I bought the boat a year ago, and I've never "jimmied" with it, but anyway I gave the cap a turn by hand and the thing cracked immediately.<br />So, now I've got to replace this cap anyway, but I am worried a bit that if some oil was escaping from under the cap, that much oil didn't make it into my gas? There were no alarms sounding, the level in the remote tank was good, so maybe it's no big deal? I'm estimating that I burned 20 gallons of gas that day, and lost a pint or so of oil. Thanks alot for any feedback on this.

 

[fgbutler]

Re: 1999 Merc EFI 175 - oil everywhere pls help!

If there was still oil in your tank at the end of the day I would not worry about it. The oil is drawn from the bottom of the tank so you would have still been getting oil to your gas. I have heard of engines running for 100 hrs. on a 100:1 ratio with no scarring. It was a test Mercury did to prove durability of there outboard oil. If this does not calm you, do a compression check.

 

[Ken Paydon]

Re: 1999 Merc EFI 175 - oil everywhere pls help!

Thanks for the reply GB... I guess my worries are that there is obviously an oil pump between the main reservoir and the remote tank on top of the engine, but is there another pump between the remote oil tank and the cylinder injectors? Or is it gravity feed from the remote tank? Sorry for the additional question, I just want to get a good understanding of the system. <br />Thanks again for all replies...

 

[dingbat]

Re: 1999 Merc EFI 175 - oil everywhere pls help!

I had my cap break last summer. I used a piece of plastic wrap under the cap to get me through the day. <br /><br />FYI: The oil is pushed up from the remote tank using air pressure from the fuel pump diaphragm. The oil is then gravity feed to a mechanical oil pump where it is mixed with the fuel. As long as you have oil in the upper tank you are OK.

 

[gss036]

Re: 1999 Merc EFI 175 - oil everywhere pls help!

I have had 2 caps break on my 200 Merc. Seems to more common than everyone things as several replies when I posted looking for a cause. Finally talked with a Merc Mech and he says since the system is pressurized, it won't hurt the engine as long as there is oil in the remote to keep filling the on-board tank. He said to keep an eye on the remote tank while running to see if was getting rounded from excessive pressure. There is a check/relief valve somewhere on the dual line going to the remote. One line goes to the block and the other to the tank.<br />Anyway, go spend $37+tax and get yourself a new one. They do not have to overly tight as they have a cork gasket in the bottom of the cap.

 

[Ken Paydon]

Re: 1999 Merc EFI 175 - oil everywhere pls help!

Thanks guys, I appreciate the feedback. I've ordered the cap, should have it before the weekend. Will run it a bit and check for leaks, then hopefully I'm off and running again.