I found oil on my bilge where is coming from

[betayv]

hello there 1984 mercruiser 228/305 went out for a ride everything look normal until i reach 3000 rpm cruising I check bilge and see some oil, I stop turn off the engine and try to fing where the oil is coming from and nothing, went again for another ride rpm went up to 3500 and again oil on the bilge, took the boat out clean the bilge start on muff and nothing where is that oil posibble coming from thanks.

 

[Bt Doctur]

Re: I found oil on my bilge where is coming from

Engine oil
drive oil
Power steering oil
Trim/Tilt oil
Can you narrow it down?

 

[Don S]

Re: I found oil on my bilge where is coming from

You may have to do what us pro's do.
We get everything cleaned up, then take the boat out and look. While it is operating. Stop occasionally and get into and look with mirrors and flashlights to see hard to get at things.
Then when we think we found the leak we decide the next step.
There is no single source of oil leaks.

 

[fishinpa]

Re: I found oil on my bilge where is coming from

Was there oil on top of the engine, on the sides , on the bottom ?
did it look like clean oil ?
have you checked (pull dipstick) to verify oil level.
Also verify that is is engine oil ?


fish

 

[Black as]

Re: I found oil on my bilge where is coming from

Check all your oil levels something got to be low and that will be your oil leak

 

[betayv]

Re: I found oil on my bilge where is coming from

is engine oil, and was on the bilge and look around to see if i can see where is coming from and nothing, pull out deep stick and oil level is correct!!!

 

[arks]

Re: I found oil on my bilge where is coming from

Clean the bilge, then put down an oil-absorbing towel or light colored cloth.
Take it for a short run until you see a drip.
Look DIRECTLY above the drip to find the source.

I don't know what else to suggest.

 

[rthomas]

Re: I found oil on my bilge where is coming from

pre 86 small block- check the valve covers, probably more likely to leak in the back at high rpm there might be quite a bit of oil up in that area. also check the oil sending unit behind the intake manifold, mine leaked there and it took me a while to figure out.

 

[betayv]

Re: I found oil on my bilge where is coming from

good info rthomas you know what I checked averything except for tha valve cover especially in the back, If i dont find nothing i going to do what arks recomend, another thing in the bilge in front of the crank pulley look like someone spray oil I check the pulley and is dry.

 

[DJ]

Re: I found oil on my bilge where is coming from

Good tip on rocker covers and sending unit. Remember, fluids are subject to gravity and flow downhill. Start at the top and work down.

 

[bowman316]

Re: I found oil on my bilge where is coming from

could be a head gasket too. I know this is apples and oranges, but with my outboard i had black oil leaking down from the powerhead, and it was a bad head gasket.
I think with an inboard, you will see oil in the antifreeze.

 

[backyard mechanic]

Re: I found oil on my bilge where is coming from

Don't know how new or old your engine is but look at your PCV valve. You may be blowing oil out the dipstick. Back pressure at high RPM is what you are looking for. Usually that is indicative of low vacuum at high RPM which correlates with engine pressure.

Most likely you will find it's a valve cover or timing chain cover leak.

 

[achris]

Re: I found oil on my bilge where is coming from

Don't know how new or old your engine is but look at your PCV valve. ....

In the first post he said it was a 1984 228. No PCV valves in these engines.

Chris.....

 

[road.ripper]

Re: I found oil on my bilge where is coming from

here is my .02

like everyone has said you kinda got to chase the leak from the drip - up
i have done a bit of small block chev work in the '80's mostly hotroddin ,
rear main seal could start to leak after the pressure builds at higher rpm.
being a mid '80's engine it could have either a 1 piece rear main or a 2 piece that being about the time they changed the small block rear main designs.

road

 

[betayv]

Re: I found oil on my bilge where is coming from

hey guys can I add some engine oil dye in to the engine and try to find the leak that way thanks...

 

[rthomas]

Re: I found oil on my bilge where is coming from

the dye would make it easy, if you narrow it down to the rear main id make a good assesment of how much oil your losing and maybey consider keeping an absorbent log under the motor instead of doing anything about it because the 2 piece rear main is a notorius leaker and replacing it may not completely stop the leak. also remember a little oil is going to make huge mess when mixed with a little water in the bilge. from the sounds of it your not looking for a gusher. when my sending unit was leaking and the valve covers were a little weepy this made a huge mess and i wasnt even using a quart/100hrs

 

[betayv]

Re: I found oil on my bilge where is coming from

hey thanks rthomas yes Is a little bit is not much oil I probably will put a absorbent pad on it, I will try to find the leak but because is a little bit probably will wait to fix it, I just have to take it easy and pay attention to the oil level.

 

[PitchFork]

Re: I found oil on my bilge where is coming from

I had been looking for an oil leak much of last season. I put many hours into finding the leak and finally found it. It was coming out of the distributor it looks like the gasket had worn out. I have not replaced it as the leak is small not even a quart in 120 hours. When I need to do some other service I will then pull all the back seats out and pull the distributor and replace the $1 gasket. Until then I will run an absorbent pad.

 

[betayv]

Re: I found oil on my bilge where is coming from

hey guys one thing I forgot to mention the fuel pump was replaced the bolts look tied and they use the paper gasket without silicone, can be posible that oil is leaking from there?.

 

[DJ]

Re: I found oil on my bilge where is coming from

hey guys one thing I forgot to mention the fuel pump was replaced the bolts look tied and they use the paper gasket without silicone, can be posible that oil is leaking from there?.

Remember-look-UP! Gravity. Major seal leaks are rare. Minor ones are not.