Oil Leaks FAQ

compiled & edited by Kristian #562
Edited by Winter, 29 December 2005
Please read the Disclaimer before attempting any work in this FAQ.
29 December 2005


From time to time your bike may develop oil leaks. It is a good idea to Clean your bike on a regular basis, as this may sometimes help you identify the source of oil leaks. As a general rule, if you have an oil leak, check any bolts that normally holt that part together - make sure they are all torqued to spec. If it is coming from a gasket of some sort, you may need to replace the gasket.

What are the Most Common Sources of Oil leaks?

by Flash #412, Kristian #562 & HsN

Well...Generally, but not in any order of frequency of occurrence, they are:

  1. The Oil Filter Cover Plate O-Ring. Either the Large O-ring may have been nipped during an Oil Change or more likely, if you didn't do it yourself, someone tightened up the Filter Cover without checking that the little black ignition wire that runs JUST beneath the Cover down to the Alternator was not kept out of the way and it got stuck under the Oil Filter Cover Plate. Refer the Classic Oil Change Chain FAQ or the Oil Change FAQ for the GS for further details.
  2. From the Oil Pressure Sensor. See the Oil Pressure Sensor FAQ.
  3. From the Sump Plug. You may have stripped it. See the Sump Plug FAQ.
  4. From the Airbox via a Circuitous Route. See the Air Filter FAQ and the GS Air Filter FAQ.
  5. From the Countershaft Seal. See the Counter Shaft Seal FAQ.
  6. From the Gear Shift Lever Seal. Replacement when on the bike follows the same procedure as the Counter Shaft Seal FAQ. Off the bike see the Water Pump FAQ or the Clutch FAQ.
  7. From a Weeping Head Gasket. See the Head Gasket Replacement FAQ.
  8. From a Broken Oil Tank (GS/Dakar only).
  9. It could just be some remaining waste oil from the previous oil change, try to clean everything and check if some new oil come off again.
  10. Q. Ok, there also was some oil leakage near the bottom of the engine, I was never quite sure if that was from the chain though (I bought the bike used). Dealer calls later in the afternoon to tell me it's the base gasket, meaning they have to order parts (~2 days) and then take the engine apart. Has anyone else have a base gasket fail? What is the cause for that? Bad parts or assembly at the factory? Abuse by the previous owner? This is all fixed under warranty, and the dealer was nice enough to offer the loaner while they're waiting for the parts and then apply some of the warranty work hours to the service as well.
    A. I had the same oil leak at about 4k miles or so. My tech thought he would have to replace the gasket but it turned out that the engine bolts were not torqued to spec. Loosened during riding? I don't know. Anyway, he tightened them to spec and the leak was gone. No problems since. Rebecca.

  11. There have been a couple of reported cases of leaks from around the RHS engine cover (where the magnito is), including the bolt just below the two bottom oil filter bolts. In my case some of the bolts were loose enough for me to unscrew by hand! Torque them all back to spec. If that fails to stop the leak, you may need to replace the gasket (not sure if this is the same as the base gasket already mentioned. Winter #1935 with input from Sean Mason

Unknown Sources of Oil Leaks

i.e. No Feedback on the ACTUAL problem. If you recognise the Symptoms, please let us know YOUR Solution.

Whitish Material Under the Oil Filler Cap?

Problem: Over the last month I've been noticing a white foamy goo on the inside of my oil cap- unscrew black cap, flip over, see white goo. I was wondering if anyone else experienced the same thing. The Mechanic at my shop had something close to cottage cheese on his, and there is no foam in the oil tank itself on either bike so I'm sure it's not a coolant leak. His guess was condensation in the tank. 5W30 - light white foam - avg riding temp 30F 2001 F650GS 4500 miles.

Short Answer:

  1. Condensation - Don't Worry About it. It's probably this.
  2. Failed Water Pump - Worry About it. Check your Coolant Level is NOT going down and your Oil Level is NOT going up and that you have no Weephole leaks. See the Water Pump Seal Repair FAQ for details