Strange Oil leak GS1150 from Engine Ventilation???

[kz]

Hi,

I have an oil leak from a hole on the front right side of the engine.

I can't understand what the hole is for?? and why oil is leaking out there.

Tried both the original and Haynes manual.

I have a new oilpump with 750 gears and the oil is Quaker State 20-50.

Is it oil preassure related?

Any help is welcome.

See: links for picture.

http://medlem.spray.se/ocorsagsi/PICT0464.jpg

http://medlem.spray.se/ocorsagsi/PICT0468.jpg

[beeh200]

hole

could be the hole that lets any fluids that go into the sparkplug cavity drain.good chance that your valve cover is leaking and is going into plug area.good luck,rob

[Anonymous]

My believe is that it?s leaking between the cases, but I?m not sure. I looked at my pics of this winters rebuild and I can see some sort of drain in the upper case. The ignition cover should be removed and check the inside behind the ignition. You may see something there.

Best of luck!

[kz]

I have removed the ignition cover earlier this morning for inspection and there was no oil.

Anybody who nows why that hole is there and what it's for?

I don't think the valve cover is leaking, but I will have an extra check.

[kz]

Re: hole

could be the hole that lets any fluids that go into the sparkplug cavity drain.good chance that your valve cover is leaking and is going into plug area.good luck,rob

Just checked if the hole is a drain from the spark plug area by putting water into the spark plug area and no water poored out of the hole.

The drain from the spark plug area simes to be in all in the cylinder head.

BTW:

Thanks for all the good luck wishes, I'm getting a feeling that I need them..... :roll:

[earlfor]

Re: Strange Oil leak GS1150 from Engine Ventilation???

Karl, I believe that is an auxillary crankcase pressure relief/breather for blowby combusion gases. The normal relief for blowby gas is the valve cover vent with the outlet hose that runs to the airbox. I would check to see if the screen and vent assembly that is mounted on top of the valve cover has a blockage or if its breather hose is blocked.

Earl

Hi,

I have an oil leak from a hole on the front right side of the engine.

I can't understand what the hole is for?? and why oil is leaking out there.

Tried both the original and Haynes manual.

I have a new oilpump with 750 gears and the oil is Quaker State 20-50.

Is it oil preassure related?

Any help is welcome.

See: links for picture.

http://medlem.spray.se/ocorsagsi/PICT0464.jpg

http://medlem.spray.se/ocorsagsi/PICT0468.jpg

[kz]

Re: Strange Oil leak GS1150 from Engine Ventilation???

I would check to see if the screen and vent assembly that is mounted on top of the valve cover has a blockage or if its breather hose is blocked.

Earl

Earl:
I changed that gasket and cleaned the valve cover only 500 km ago, maybe I mounted something wrong, I will check.

Chrille_08:
If it's leaking between the cases, what?s next? splitting the engine? :roll:

[rosco15]

I looked at a set of black 1100 cases. I can see the other end of the hole when I split them. One half of the cases are hollow making a passage that leads into the area behind the ignition cover. It looks like some kind of a vent to me. Of course there is no oil in there so I would guess it's coming from between the cases. The disclaimer here is that I'm looking at late model 1100 cases and not 1150 cases.

[earlfor]

I fitted a vinyl tube to the hole/vent tightly and blew through it. Air passes freely through the hole. My 1150 does not leak through that hole, so my conclusion is that it is a vent and is supposed to be open. If there is oil coming out of the hole, then there has to be pressure in the crankcase to force it out. There should not be pressure in the crankcase. I do not feel the vent is the problem. I believe it is the bypass for a problem that should not be. There has to be a reason why there is crankcase pressure.
I would also try running the bike with the oil fill cap loose so there can be no pressure build up to see if that stops the leak. (tape/secure the cap so it will not vibrate loose and be lost) If the leak stops, then we know it is a pressure problem. The only other pressure relief measure I know of on the engine is the oil breather assembly that is mounted on top of the valve cover.

It may be possible to overfill the oil level and cause the problem but I can not imagine that could be the cause. (all things considered :-) )

I have received valve cover gaskets that did not have the center portion where the valve cover breather assembly is mounted, punched out in the gasket. I feel rather silly asking this question, but are you sure the gasket is open underneath the breather assembly. :-)
(I know, go ahead and slap me for asking) :-) :-)

Earl

[kz]

Thanks for your answers.

Ryan, (Rosco15):

It looks to me that "half of the hole" has connection to the area behind the ignition cover and the other half has connection to the crankcase (but I'm not sure).

When you write "I would guess it's coming from between the cases" do you then mean that the gasket between the upper and lower case probably is leaking? or do think anything else is wrong?

Earl:

As I mounted the gasket for the vent assembly on the valve cover, I first couldn't understand how it should be mounted.

As i mounted the gasket I was not 100% sure if it was right mounted.

It is possible that the gasket is wrong or wrong mounted.

As I first started the bike after this winter the oil level was high, maybe a little to high.

Other thoughts:

I mounted 750 oilpump gears, any influence?

I have not the optimal oil viscosity 20- 50 W, shifting is hard, any influence?

It has been "rather cold" last week, started my trip to the office at -5 C last Friday, during the day the temp was max. +6 C.

All that probably increase the oil preassure, any influence?

Should I try to:

change oil to 10-40?
change the oil pump gears back to stock?

[earlfor]

Earl:

It is possible that the gasket is wrong or wrong mounted.

**********the valve cover breather is square, so the gasket could be reversed which may block off the opening underneath*******



As I first started the bike after this winter the oil level was high, maybe a little to high.

************ I would put the bike on the centerstand and drain oil if needed so that the oil level is between the marks**********



Other thoughts:

I mounted 750 oilpump gears, any influence?

**********That is a common modification and no one else has had a problem with it. I doubt that is the cause.**********



I have not the optimal oil viscosity 20- 50 W, shifting is hard, any influence?
************I found shifting smoothness was much improved when I changed to synthetic Mobil 1 15w50. I have used 10w40, 20w50 and 15w50 and oil weight and type does seem to make difference in smoothness of shifting. I do not think it could make a difference in your oil leak problem.********


It has been "rather cold" last week, started my trip to the office at -5 C last Friday, during the day the temp was max. +6 C.

All that probably increase the oil preassure, any influence?

*********I think it would only make a difference until the oil/engine warmed up. After that, the oil pressure should be the same.*******



Should I try to:

change oil to 10-40?
change the oil pump gears back to stock?

**********I would not do either because I do not think they are the cause of the problem. The oil pump takes oil rom the crankcase and pressurizes it. It does not add pressure to it. When you remove the oil filler cap with the engine running, no pressure escapes. *******

Earl

[kz]

OK, I start with the vent gasket, and double check the oil level.

It's to late for today, but I will try during the week.

I really hope your theory is right Earl!

I let you know the result.

Thanks again, so far...

[earlfor]

That makes two of us. :-)

Earl

[quote="kz"]
I really hope your theory is right Earl!

[Dink]

Karl if you dont find a problem with the breather on the camcover I suggest that you re-torque the cases, that is what fixed it on my 1150.
Dink

[rosco15]

half of the hole has connection to the area behind the ignition cover and the other half has connection to the outside air where your seeing the leak. I would think the oil is coming from between the upper and lower portion of the cases. There is no gasket just some case sealer smeared between the two halves. I can email you a pic of what it looks like with the cases split if you want.