1996 Rinker 180 Losing Oil

emtff

Hi everyone, my name is Amanda. .. first time boat owner here. My husband and I just purchased a 96 Rinker 180, 3.0 Mercruiser. We are leaking oil out the breather tube facing the flame arrestor. When it has been running for about 20 minutes the motor starts clattering and we stop to find that the oil is empty. Any ideas on how to fix this? Any help is greatly appreciated as it is hard to get a 9 and 10 year old to understand why we can't take it out too often. Thanks!

212rowboat

Good news: it may be a five dollar pcv valve that's stuck open and siphoning oil and sending it through the induction.

In the middle: could be worn valve guides allowing oil past valve stem and into cylinders.. it happens.. not expensive, but tedious at times to do.. Will take you a few hours..

Bad news: it could be worn rings and excessive blow by.. New engine time as it's likely just as expensive to rebuild..

You're going to be needing a compression test.

aero3113

Hello and welcome to the forum! There's a chance that you might have too much oil in the engine. When there is too much oil the crank hits the oil and froths it causing the clattering you may be hearing. I had this issue last year on my 5.7 once I took some oil out (I put it in the middle of the ADD FILL marks) the clattering went away. When you check your oil after running let it sit for about 10 minutes to get a true reading. Also make sure your not losing oil from the bottom of your oil pan, there could be some corrosion causing a leak. As for the oil coming out of the breather, check your PCV valve, it could be clogged.

Black_Diamond

Welcome aboard! 

I'll add a few thoughts too, besides all the premium ones above

1. check the oil when cold to make sure it is at the correct level.  A fresh oil change and filter might be worth the effort too.

2. When you check the oil and it is 'empty'..I assume this is when it is making noise and not after setting awhile?  There is almost no way you are burning or leaking 4+ qts of oil in 20 minutes without a huge mess or a huge cloud behind your boat.  I bet the oil is not draining back into the pan (assuming the oil level is correct to start with)..meaning it is probably trapped in the valve covers due to sludge plugging up the oil drain holes.

3.  ++ on replacing the PCV valve

 

Let us know what you find out!

emtff

Hi, thanks for your suggestions. After my husband got some time, he found that the oil is pouring from between the motor and the drive. He said he doesn't have to remove the transom, but I don't know where to go from here. Hoping it is not a major expense, we have only had it out a couple times and summer just started.  #-o

212rowboat

rear main seal.... if it is a two piece part, as opposed to a one piece, it's not that big a deal... i would guess removing the engine is smart, to do it, though... and while you're in there...................................................................

Black_Diamond

Ah, it is a big mess then. That's a pull the motor job for sure. As Drew mentioned, while it is out it is a good time to look after other items like your outdrive bellows, ujoints, coupler, raw water pump, hoses....

emtff

He got the motor pulled and sure enough it is the gasket. Any experience with insta gasket? He thought about trying that as opposed to the $80+ gasket. 

Black_Diamond

Oil pan gasket?  No way I would waste my time with instagasket. Sure it is not a rear main leak?  Pan gasket would be hard to leak out quarts of oil that fast. I would look at oil galley plugs for leaks and and block/head cracks too. 

TikiHut2

It's a boat and you got lucky it wasn't a major malfunction $$$. Figure it as good luck/grace and just pony up and get the right gaskets/seals in there to avoid another engine pull in the near future. I'm with BD and Drew that it sounds like a rear main seal or even a hole in the oil pan (not uncommon and non-repairable).

I just pulled my engine out yesterday and I'm doing everything I can to avoid re-pulling it anytime soon. Everything underneath that motor deserves your main guys undivided attn from spark plugs to starter and water pump.

Putting it back together pay extra attention to the motor-to-outdrive alignment or it'll get really expensive. It's not just a re-bolt everything and plug on the OD kind of deal. It's a weak link for many mechanics who are close to the finish line and fudge it. ANY amount of misalignment can/will create a major drive line expense. If he can't pull out the alignment tool with only two fingers with the motor at TDC/90*/180*/270* then he needs to work those adjusters until he can.

Good luck and welcome to the forum. Mike