thompsdw
New Member
I am commonly finding this after a good run on the boat. Lotta water, little oil. Not enough to show on a dipstick. Any problem spots on the 454 to start looking at?
Engine leak into bilge
- Thread starter thompsdw
- Start date
bport
New Member
A mechanic showed me an easy way to locate a small oil leak like this. Get a couple of oil-absorbant sheets (from a marine store) and lay them in the bilge. You will know where the leak is originating by where the oil drops fall.
Uplate
New Member
- Oct 13, 2008
- 977
- Boat Info
- 1998 Sea Ray Sundancer 310
Westebeke 4KW Generator
- Engines
- Twin 5.7 Mercruiser Carbuerated.
Alpha 1 Drives
.Mine end up being the cap of one of the blue plastic drain plugs had broken off. It left a pin hole in the threaded shank that spit water. After looking at the more obvious things like hoses you may want to check these plugs to make sure they are tight and not broken.
Before I re powered a few years ago I always had some water in the bilge. Found a cracked block (probably freeze damage) was the culprit. Hope yours is a simple fix.
techmitch
Well-Known Member
- May 1, 2008
- 8,421
- Boat Info
- 1999 270 DA
- Engines
- Twin 4.3s W/Alpa I Gen II's
Glad the water was an easy fix. What was/is the oil leak?
Are you positive it only happens when the boat is running (moving), or does it also happen if you just let the engine idle for a while?
Is the bilge area spotless, especially under the engine? Is the engine spotless? This would be good to know to eliminate some variables, such as if the water is dripping down along the engine and picking up trace amounts of oil along the way, or is the water entering through another area and simply gathering trace amounts of oil sitting somewhere on the bilge floor.
Along the lines of what what was mentioned above, another thing to do is just tape down paper towels all over the place and check it every few minutes. This will at least help to narrow down your search area. You can even try stretching paper towels (or maybe something a little stronger like craft paper) across the "V" of the bilge -- that could help to eliminate confusion of water dripping off the engine compared to another way that the water gets to the bilge floor.
Another thing to do - just start poking your head around (a flashlight and a mirror-on-a-stick will help) the engine looking for tell-tale signs of water leaking out... raw water pump, circ pump, fittings, hoses, sensors/senders, etc. Not just on the front of the engine, too.
Is the bilge area spotless, especially under the engine? Is the engine spotless? This would be good to know to eliminate some variables, such as if the water is dripping down along the engine and picking up trace amounts of oil along the way, or is the water entering through another area and simply gathering trace amounts of oil sitting somewhere on the bilge floor.
Along the lines of what what was mentioned above, another thing to do is just tape down paper towels all over the place and check it every few minutes. This will at least help to narrow down your search area. You can even try stretching paper towels (or maybe something a little stronger like craft paper) across the "V" of the bilge -- that could help to eliminate confusion of water dripping off the engine compared to another way that the water gets to the bilge floor.
Another thing to do - just start poking your head around (a flashlight and a mirror-on-a-stick will help) the engine looking for tell-tale signs of water leaking out... raw water pump, circ pump, fittings, hoses, sensors/senders, etc. Not just on the front of the engine, too.
Bob & Sue
Active Member
I would do all the above I had some sea water and oil in the bilge after Sea Ray pulled the engine to replace the coupler 2 years ago it was a loose hose at the rear oil cooler after tightening the clamps haven't had a drip of water or oil in the bilge. I now make it a practice to check all clamps and wire connections I can reach about once a month I was surprised how many things will loosen over time with all the vibration on a boat engine.
boatrboy
Well-Known Member
All good suggestions - I will add some of my leaks
The oil cooler lines had slight leaks where the rubber was crimped to the fittings. I replace both lines over the last few years
The oil cooler lines enter an adapter where the original oil filter screws on - port side rear motor - this had a large nut on it and I found the seal under this adapter leaked slightly dripping oil into the bilge - took me a while to find it, but a mirror on a stick helped.
Feel the bottom of the raw water pump and see if it wet. I fought a little with this once too.
I ended up soldering a plug in my fuel pump cooler drain where the plastic plug goes - I never got it to stop dripping - (if I need to drain the water i just pull the hose)
NOW - last year - this shot glass of water got the best of me so I found out that the steering pin seal was leaking so I pulled the motor and rebuilt my transom assembly last year. I put paper towels in the pocket where the lever is and one ride told the story.
Good luck - I don't like a wet bilge either
The oil cooler lines had slight leaks where the rubber was crimped to the fittings. I replace both lines over the last few years
The oil cooler lines enter an adapter where the original oil filter screws on - port side rear motor - this had a large nut on it and I found the seal under this adapter leaked slightly dripping oil into the bilge - took me a while to find it, but a mirror on a stick helped.
Feel the bottom of the raw water pump and see if it wet. I fought a little with this once too.
I ended up soldering a plug in my fuel pump cooler drain where the plastic plug goes - I never got it to stop dripping - (if I need to drain the water i just pull the hose)
NOW - last year - this shot glass of water got the best of me so I found out that the steering pin seal was leaking so I pulled the motor and rebuilt my transom assembly last year. I put paper towels in the pocket where the lever is and one ride told the story.
Good luck - I don't like a wet bilge either
thompsdw
New Member
I am more thinking now that the leak occurs after engine has run and not during. Does that point me in a different direction?
What is making you thinking that? There were some very good suggestions and things to try mentioned above - all aimed at narrowing down the possibilities - what have you tried that leads you to this conclusion?
- Jun 2, 2008
- 5,024
- Boat Info
- 1998 450 Sundancer, Achilles dinghy w/15hp
- Engines
- 3126 Cat's
My very simple thought (and yes consider the source) was mentioned earlier as a raw water pump.... You have both elements involved: water and oil. So, the water seal is failing worse then oil seal and that is what you have in the bilge ??? What I have learned from my marine experiences is to start at the lowest budget item and then work up very slowly... In a previous life I would jump in with the checkbook first = WRONG...
