Oil Seepage Theory

[Guest]

I get oil seepage in a couple of areas, but not all the time. Base gasket, clutch pivot seal, RH crankshaft seal (behind the ignition), for example. My crankcase will stay clean for weeks, then I’ll start to notice some trails forming and get some drops of oil on my right shoe every couple of days.

So here’s my idea – you think as my oil “wears out” and starts to lose viscosity (I’ve read that it does that) it’s getting through the seals better?

My bike’s an ‘81 GS850G with about 38K miles. I put on 250-300 miles per week between errands and my 50mi round trip freeway commute. I’ve been using 15W-40 dino oil (Rotella T, if you must know, but I don't want to start an oil debate thread if I can help it) and changing it about every 2000 miles. It’s about due for a change, which is what made me think there might be a pattern to the leaking.

I’m changing the oil this weekend, so I’ll certainly clean things up and see if the seeping goes away for a few weeks – I’m just curious what you guys think.

[bwringer]

After a couple of decades, rubber seals harden and seep, especially when the oil is hot and at its thinnest.

So yes, you will see a bit more leakage and seeping when your oil is old and hot.

On the bright side, replacing the offending seals and gaskets should cure the leaks. A GS isn't like an old British or American engine, where they are seemingly designed to leak no matter what. A GS with reasonably fresh seals and gaskets won't leak a drop anywhere.

Plus, all the seals and gaskets are still available from Suzuki at pretty reasonable prices.

[chef1366]

My GS1100 is the first bike I ever owned that didn't leave oil drip spots.

[fgh]

Well, yes the oil does lose viscosity as it ages. One of the benefits of a true synthetic is that it'll keep it viscosity longer. As you probably know not all "Synethics" are synthetic. My local NAPA store carries about ten different synthetics and only one is really synthetic. If you change your oil at 2K the synthetics are a waste of money.

Its true that gaskets harden and crack and lose there seal after a while. The metal in the engine fatigues also. Your bolts can also lose their tensile strength and will stretch a little when you torque them so that they are as tight as the wrench says they are. The long and short of it is as engines age they will be prone to leak more. When it gets too bad install new seals and gaskets properly and hope for the best. LOL!!

[knotzilla]

Would a blocked breather hose cause a higher pressure inside the engine that might also to oil leaks? Ted

[chef1366]

Would a blocked breather hose cause a higher pressure inside the engine that might also to oil leaks? Ted

YES! .....................

[bwringer]

Would a blocked breather hose cause a higher pressure inside the engine that might also to oil leaks? Ted

It certainly could, but I think r. bunny has probably already looked into this possibility -- it came up not too long ago.

[Roostabunny]

Would a blocked breather hose cause a higher pressure inside the engine that might also to oil leaks? Ted

Good thought. Brian's right - I discovered breather blockage a couple of weeks ago while working on resealing my airbox, so that's probably not it, but I'm sure it was contributing in the past.