View Full Version : Searching for oil leak on a 2007 LY6 X-Star

01-16-2012, 08:21 AM
Hi, the search didn't really help me, so I'm trying it here.

We have a 2007 X-Star with the LY6 engine.
In the end of the last season we recognized we had some considerable amount of oil in the bilge.
We started searching for the origin as long as the boat was in the water but couldn't really locate anything. We cleaned out the bilge and checked the visible parts of the engine quiet often.
We had to refill the engine oil more often then before (No need inbetween oilchanges before, really).
It seemed that the usage with full-ballast increased the need to refill oil.
V-Drive and Gearbox show no sign of oil-loss.
We have hydraulic stearing but haven't yet checked for the oil in there since we don't know where.
We're planning on cleaning up the full engine and letting it run with fake-a-lake to find the problem before we throw it back in the water.

Any hints and help on where we might look for the problem are more then welcome! Thanks

01-16-2012, 08:46 AM
Hate to say it but you might have excessive blow by.

01-16-2012, 09:02 AM
Thanks for the fast response.

I wouldn't believe it could be blow by since the upper/easily accessible part of the engine including airfilter and housing are totally dry. No oil anywhere there.
It must come from somewhere near the bilge under the engine, V-drive or gearbox or something we haven't thought of.
[The lock-ring of the crank shaft is dry also, by the way.)

01-16-2012, 09:17 AM
Did you check the oil drain hose where it connects to the oil pan? Perhaps the gasket there is seeping a bit. Might be difficult to see/tighten since it's so close to the boat.

Also make sure your PCV valve is working properly (if your engine has one). Just replace it to be safe (cheap part)

01-16-2012, 09:35 AM
The oil drain hose was one of our ideas to where the problem might be. Is the gasket where it is attached to the oil pan a frequent source for oil leak?

(We'll check on the PCV valve to. Thanks)

Any other hints or experiences? We're really trying to gather as much information as we can before performing a test.

01-16-2012, 10:39 AM
Not sure if there are any trouble areas on that engine. Check the usual places like valve covers, oil pressure switch, rear main seal, front seal, etc.

I would lay white cardboard around the whole bilge area under the engine and then run it on the hose. At least that way you can spot the oil leak area.

There is also oil dye you can buy from the auto parts store but you need a black light too.
You add the dye to the engine oil, run it then look around for leaks with the black light.

01-16-2012, 10:46 AM
how many hours on boat? Any performance issues? How do spark plugs look? What do you consider a "considerable amount of oil in bilge"?

Do you get alot of water in your bilge when running? I am just asking because I am thinking the same thing about the oil drain hose gasket.

Rear main seal is where I would look. I agree on the blow by...you would also notice loss of power with that much blow by.

01-16-2012, 06:28 PM
Yes, rear main seal, too bad not very visible

01-17-2012, 10:48 AM
Thanks a lot everyone.

We've got about 760 hours on the boat (no we're not a school or camp just addicted). But the engine is very well maintaned.
We don't have any performance issues at all. No power loss at any rpdm, no increased fuel consumtion, no unusal sounds.
The sparkplugs are dry and look good. A little on the white side probably but that will be due to running on LPG most of the time.
A considerable amount of oil is looking like a mess when You look in the bilge. It's not just a hint of oil in the bilge's water but it's not a quater gallon sitting in the bilge either.
We don't get a lot of water in the bilge when running. Just a little from the rudder really and near to none frome the propeller shaft. But we flushed it with the drain plug some when it was in the water to rinse the bilge and determine the leak.

Holman J.B.F
01-17-2012, 03:43 PM
Tom?..Check this seal.

01-19-2012, 02:09 AM
Hi Ben! It's Heinz. Thanks a lot for the hint.
We found some oil on the small hose beneath this seal. So this might be the solution.
How are You doing? Say Hello to Able for me please.

01-19-2012, 09:28 AM
Tom?..Check this seal.

+1 on this... my least favorite seal of all time on the street and the sea (ok river, lake, pond...etc...)

Holman J.B.F
01-19-2012, 10:40 AM
well,..good luck replacing it.
Just make sure you have the right tool for it,i replaced mine it had a small leak,hardly noticeble but i hated the oil smell.
say hello to Tom.

Hi Ben! It's Heinz. Thanks a lot for the hint.
We found some oil on the small hose beneath this seal. So this might be the solution.
How are You doing? Say Hello to Able for me please.