Oil Seeping from Intake (air filter)
- Thread starter derail
- Start date
Oil blow-by is very common on these engines especially if you drive them hard in the heat. I had the stage 1 air kit from HD and I was going to tap in the backing plate and run two braided lines under the bike to the ground. Some guys run them to a small catch can and drain it once in a while. I was going to do this but then I looked at HD Heavy Breather. The big elbow on the Heavy Breather comes out of the intake and kinda goes up a bit to the cone filter. Any oil that accumulates will sit in the bottom of the elbow rather than in your filter. This small amount of oil eventually gets sucked up and there is never any mess. I have had mine for 3 years with no problems at all plus it looks cool too.
+1 What Bodeen said!
Changed to the V&H naked system, and the problem has gone away. They have incorporated tubes that direct the breathers right into the intake. Had the oil problems with the SE and the Big Sucker. Fought the problem for the first 30k miles on my 010 CVO ultra, last 10k miles, not a drop in the filter. Same bike same conditions, same oil and oil level. :bigsmiley23:
Iceman24
Well-Known Member
derail
New Member
I don't buy the 'run the oil low' school of though. Besides, it's such an important part of the cooling process that running less is asking for trouble. Mine will seep low or at the full mark. I've read that some folks will stick a Kotex at the bottom of the air cover and this helps sop up the residue but I'd still be interested in finding out why this happens in the first place.
Iceman24
Well-Known Member
Well...that's your choice, but then you'll need to learn to live with the fact of having oil drips/stains on your bike + leg.
HD motors are designed so the crankcase vents into the air cleaner. Air under the pistons on the downstroke of the crankshaft has to be vented & the normal way of doing this is to vent it into the A/C. This air has a mist of oil in it and is vented so MOST of it gets recirculated through the intake and out the exhaust, however, some of that oil mist collects on the air filter and, over time, drips. This is perfectly normal....exactly why regularly scheduled maintenace of the air filter is needed. My oil temp never runs over max spec - even during hot/muggy summer rides & I run level 1/2 qt low. Now if you want to start stuffing objects inside your intake - go ahead, but that sounds more damaging than a little less oil...imaging that cotton ball getting sucked inside your motor. >.<
HD motors are designed so the crankcase vents into the air cleaner. Air under the pistons on the downstroke of the crankshaft has to be vented & the normal way of doing this is to vent it into the A/C. This air has a mist of oil in it and is vented so MOST of it gets recirculated through the intake and out the exhaust, however, some of that oil mist collects on the air filter and, over time, drips. This is perfectly normal....exactly why regularly scheduled maintenace of the air filter is needed. My oil temp never runs over max spec - even during hot/muggy summer rides & I run level 1/2 qt low. Now if you want to start stuffing objects inside your intake - go ahead, but that sounds more damaging than a little less oil...imaging that cotton ball getting sucked inside your motor. >.<
Hoople
Account Removed
I don't see it as running the oil level low because it's a dry sump system.
I always found a bunch of oil in my stock air cleaner from day 1. This being my first dry sump engine, I would always fill my oil to the full mark. Now I fill to 1/4" below full mark (when hot) and I no longer find oil in the air cleaner.
I'm thinking (just my own theory) that since this is a dry sump system, a high fill level in the oil tank.will create a higher pressure for the scavenger side of the oil pump to work against. This in-turn has to create a slightly higher level of oil within the sump/crankcase during engine operation. That in turn makes the oil mist (droplets) within the crankcase more rich in oil content which easily finds its way inside the air cleaner.
Yes, no, maybe? I have no clue but a slightly lower tank level works for me also.