[Zeke]

Hey all;

I have a very small oil leak that is getting worse. Ive done a full engine clean to locate the leak. It looks to be under the water pump area, but not the water pump.
What can leak in that area? Its not the valve cover. Can it be the oil pressure switch? is there a seal behind the water pump. I looked at the fiche but dont see a seal of any kind.
Thanks for any help.

Zeke

 

[K100Dennis]

There is a tell-tale hole in the casting between the water and oil pump housings, it faces downwards. If oil is there then the oil pump seal is leaking. If there is oil around the oil pressure switch threads then that needs to be removed and re-sealed. If neither of these is the issue, then it's possible that the metal to metal joint between the engine case and the oul pump housing is weeping. Not normal, but possible. This being the case, the oil/water pump needs to be removed from the engine and the joint re-made. BMW specifies a ThreeBond product (1207 ??) I think. This is/can be a very technical joint to get right as it is under full system (oil) pressure and is reliant only on the sealant. Proper preparation is the key to a successful result. Failing this, I can't think of any other obvious source for the oil leak except a loose oil pan. Hope this helps.

 

[Zeke]

There is a tell-tale hole in the casting between the water and oil pump housings, it faces downwards. If oil is there then the oil pump seal is leaking. If there is oil around the oil pressure switch threads then that needs to be removed and re-sealed. If neither of these is the issue, then it's possible that the metal to metal joint between the engine case and the oul pump housing is weeping. Not normal, but possible. This being the case, the oil/water pump needs to be removed from the engine and the joint re-made. BMW specifies a ThreeBond product (1207 ??) I think. This is/can be a very technical joint to get right as it is under full system (oil) pressure and is reliant only on the sealant. Proper preparation is the key to a successful result. Failing this, I can't think of any other obvious source for the oil leak except a loose oil pan. Hope this helps.

Helps alot. I am going to check that area again. I ride a hour to work every day so I will check. Its raining pretty hard, so I may have to check tomorrow. I did not see a pump seal on the fiche, but I will look again. Hard to change out? I replaced the clutch, so after that most things are pretty simple. I have "high" mileage, so might as well rebuild the water pump while I'm in there. Thanks again, I will let you know what I find.

 

[clayton]

Zeke, sounds like your on the right track with the leak coming from the oil pump area. How many mile are on the bike?

 

[walkke74]

Hi
I have a 2005 LT and I too have a small oil leak at the front of the engine, I had a full service done by the main dealer and mentioned it to them at the time, they diagnosed a possible oil temp sensor switch leak so they duly ordered me the part in. They did say that this was the cheaper option as it may be the oil water pump housing leaking from the seal and from there experience the best fix would be to replace the whole unit (which I expect would be costly) they had the bike back in to retrospectively fit the new switch, and I have since checked it and it is still leaking, there is a little pool of oil sitting on the lip of the engine spoiler and the whole area around the oil / water temp switch looks damp, but I haven't noticed a tell tale hole in the casting? so am unsure if it is leaking from there or not, I am at odds as to whether to take it back to the main dealer and put my faith in them or just keep an eye on it which I am reluctant to do but don't have the additional funds to pay the possible repair bill.
Is this a common fault and if so what is the usual suspect / fix
Any help greatly appreciated.

 

[Zeke]

Zeke, sounds like your on the right track with the leak coming from the oil pump area. How many mile are on the bike?

242,000, so something was due to leak. No problems with that. I found the oil/water pump assy online for 225$, better than 415 from BMW. If its used, its still new to me.LOL

Any one changed one before, any thing I should be aware of? Looks fairly straightforward from the manual.?


Zeke