So I recently did my valve clearances, and after a few rides (one about 45 minutes or so) I noticed I had some oil leaking through my valve cover gasket and breather cover gasket (at least I think so from where the oil ended up). I tore her down and found my bolts had all loosened greatly and re-torqued them thinking I had solved the problem, but alas I have more oil leaking from both gaskets once again.
I will add that the valve cover gasket is leaking from a spot where there was a slight tear along the outside edge of the gasket (not crossing the part that goes into the groove). But my breather cover gasket seemed to be 100% good to me. This time all bolts are still tight. I also noticed the first time that I had a bit of oil in the breather hose, and I'm not sure what to make of this. I've googled a fair bit on the subject and get primarily Harley-related information.
I have new gaskets on the way now, but I was just wondering if perhaps the valve clearance change could be putting more pressure on my seals? My bike is an '09 and I figured that I should have been able to get at least one reuse out of the gaskets considering this is supposed to be a 4000 mile routine maintenance procedure.
I've changed valve cover gaskets about every 30k miles for my 180k GS miles, every 3rd or 4th valve check. Checking your valves would not cause anymore or less pressure on your seals.
Quote from: gsJack on July 07, 2014, 06:58:24 PM
I've changed valve cover gaskets about every 30k miles for my 180k GS miles, every 3rd or 4th valve check. Checking your valves would not cause anymore or less pressure on your seals.
K, just me being paranoid then. I was more wondering if greatly increasing the exhaust clearances from almost naught to .004" might put more pressure on the system (valves are not open as long). I assume there's a reason the valve cover must be sealed...
I'm going to take no news as good news about oil in the breather hose. From what I gather the Harleys that do this have similar oil systems to the GS and it is natural behavior for them when ridden after sitting awhile. I do know this didn't seem to be happening before the clearance change (hose was dry, no signs of oil in airbox), so I assumed these two are somehow linked.
Quote from: DoktoroKiu on July 08, 2014, 06:14:34 AM...........I assume there's a reason the valve cover must be sealed...........
For a demo of the reason just crank your engine over without starting next time you have the valve cover off and observe the flow of oil to the top of the head fill it and overflow onto the floor in seconds. Besides lubricating the oil cools by carrying heat from the combustion area to the sump to cool. :icon_lol:
Nothing particularly wrong with a little oil in the breather tube, it vents the crankcase area of the engine where pressure builds up when running. Water is a natural byproduct of internal combustion and that's an oily watery mix of gases that condenses in the breather area, much more on a worn engine than a newer one.
Is it a significant amount of oil you are seeing coming out of the pipe or is it just mist?
Is the wire wool separator still in place under the breather cover?...it looks like a Brillo pad
Did you replace the breather gasket and if so did you fit it correctly......with the two holes towards the front?
Did you run the engine prior to removing the valve cover and when you took the cover off the engine was it left `upside down` for some time?
Assuming it was..........could the oil you are seeing coming out of the pipe drained into it from the internal surfaces of the cover?
Quote from: sledge on July 08, 2014, 08:24:27 AM
Is it a significant amount of oil you are seeing coming out of the pipe or is it just mist?
Is the wire wool separator still in place under the breather cover?...it looks like a Brillo pad
Did you replace the breather gasket and if so did you fit it correctly......with the two holes towards the front?
Did you run the engine prior to removing the valve cover and when you took the cover off the engine was it left `upside down` for some time?
Assuming it was..........could the oil you are seeing coming out of the pipe drained into it from the internal surfaces of the cover?
Thanks for the input; here's my answers:
I only noticed the oil secondhand after removing the hose, but a mist would seem appropriate for the amount of oil found (just a slight coating).
The separator is still in place.
I did not replace the breather gasket (it remained on the valve cover IIRC).
I let the bike sit for 2 days before removing the cover, but it was upside down for some time (makes me wonder if I damaged the breather gasket by doing this). I suppose it could be some oil that drained during that time.
I'll report back after doing some more riding tomorrow to see how much more leakage I get.
Mist is nothing to worry about,
OK, I'm starting to think that maybe I have an issue with the breather system or somehow my valve clearance job has increased piston blowby. I've read that a blocked/failed breather system will allow pressure to build up enough to cause gaskets to fail, which is what I'm seeing, but then I'm at a loss to describe how it is venting oil into the airbox if it is blocked. Apparently hot oil is easily displaced through the breather system if the pressure is building up.
Does anyone know if increasing (returning) piston compression could increase blowby? My exhaust valves were almost certainly not sealing before, so could the decreased compression have hidden this issue? I did open the clearances to around 0.1mm, which according to my understanding increases the exhaust gas pressure. I think I may try to back up the clearances to .08 when I'm replacing the gaskets just to be on the safe side.
Or I could be overreacting to a pair of leaky gaskets, but something tells me oil leaking from the breather gasket isn't normal. To collect several drops over a 15-minute ride this morning seems to me to rule out oil vapors as the cause.
It isn't adding up :dunno_black:
Poorly seating valves reduce compression in the chamber and consequently blow-by and crankcase pressure. Are you 100% sure the bike isn't overfilled because this is usually the #1 cause of your problem. If compression was significantly low the bike will be difficult to start and run like sh**.
Try running the engine with the oil filler plug out, put your thumb over the hole and see if any significant pressure builds up. It may take a few minutes to get there.
I would be tempted to remove all the breather parts and clean them out in the hope that what oil is presently coming out found its way into the breather by accident when the cover was off.
Make sure the breather cover gasket is fitted with the 2 holes at the front. If its not the fumes can bypass the separator....(I think)!
After that you have to start considering the possibility of worn or stuck rings and then worn pistons and bores but this just doesn't happen overnight.
Can you lay your hands on some Redex or some other proprietary upper cylinder lube? A dash or two down the plug holes overnight will go some way in freeing off the rings if they are sticking.
Quote from: sledge on July 09, 2014, 08:24:12 AM
It isn't adding up :dunno_black:
Poorly seating valves reduce compression in the chamber and consequently blow-by and crankcase pressure. Are you 100% sure the bike isn't overfilled because this is usually the #1 cause of your problem. If compression was significantly low the bike will be difficult to start and run like sh**.
Ah, I wasn't clear; I went from super tight poorly-seated valves to in-spec valves (with the exception of slightly wide .1mm clearances on the exhaust). The bike did run like shi** and was very hard to start and keep running without keeping it choked, but now it starts and runs great. I had poor compression before, but now I'm back in spec. I didn't notice this oil issue before the valve shim adjustment, but now I do. I was wondering if this increased compression would also lead to more blowby/crankcase pressure as you mentioned.
I'll try the thumb-plug test tonight to see if I get anything. So if everything is in order I shouldn't get any significant pressure? I'll also re-check the oil level, as I did fill her up on a
very slightly inclined driveway (rear lower than front), but I also saw this before changing the oil.
For the gasket you mean front as in toward the front tire of the bike, correct? I'll check that once I get the new gaskets and such, but as I mentioned I left it installed on the valve cover as it was (maybe it was serviced and installed improperly, though; you never know). Good idea about cleaning everything out before the reinstall.
I'll definitely try the Redex in any case.
Hmm, took a second look at my owner's manual and found that you're not supposed to check the oil on the center stand. I'll bet I overfilled it since the forward angle will affect the readout.
Be back tomorrow with my results.
If you didn't put more than 3 qts of oil in you didn't over fill it. I put 3 qts in every change with/without filter change and it's below the line a bit with filter change and above without. Sometimes it's a bit above the flat onto the round part of the dipstick particularly when adding oil later. Hasn't been a problem for 180k GS miles. I change oil on ctr stand and checked it same way for years. Now I just sit on it on the ground to check so my old back doesn't have to lift it so often. Makes little difference whether it's on stand or ground when checked.
+1 on checking the oil on the center stand.
Most bikes recommend that you keep it level that is it, personally if I'd try to straddle the bike and get an oil reading it would be incorrect since I would be leaning over the bike to get to the dipstick. I guess that I don't wait long enough for all of my oil to drain or some thing because I measure 2600cc (stamped on the case) in a funnel and only put that in ever time, usually I'm just right on the oil change. 400 CC wont make much of a difference for me anyways I usually change it every 2k. I could go longer on an oil change since I run full syn but I ride it like I stole and its cheap insurance.
Hmm, I checked mine last night off the center stand and I got a consistent reading slightly above max (I filled to just under max on center stand). I originally did count on 3 quarts being good, but then I had to re-install my filter cover because somehow a bit of dirt got squeezed into the cover seal and I was leaking oil bad as soon as I started her up. So I had to put about 1/3 of a quart back into her after draining and reinstalling everything (didn't know I could work on the filter cover without draining the oil at the time).
For me (5'5" 130lb) it is much easier to check the oil while balancing the bike than it is for me to put her on the center stand. If you don't want to balance it you can insert the (dry) dipstick with the bike on the side stand, walk around, lift the bike to level for 10-15 seconds, put it back on the side stand, and then check the dipstick.
There may be a very small difference between centerstand vs balanced, but maybe I compounded that error by being on a slightly inclined surface (to make it easier to get on the centerstand, ironically).
I didn't have time to do the thumb test last night, but I'll try to do it tonight. I see no obvious new leaks from the last two trips, so hopefully it was just leaky gaskets and too much oil.