Oil in A/C @ 5000 Mile Service

[twincamzz]

Back on August 27th I brought my 2017 Limited Low home... 2 months ago yesterday to be exact. Today I hit 5000 miles and did the 5K service which included cleaning the air filter element. I did not inspect the  air filter at 1000 miles, so this was the first time I had it opened up. STOCK air filter assembly, BTW. Was surprised to see about a 1/2 teaspoon of oil pooled inside the intake. Air filter element was not soaked with oil, just small amount of oil pooled in intake. Was hoping the new breathing system in the M8 would prevent this from happening.

What's the opinion, anything to be worried about ? I do ride freeway speeds a lot, possibly this is a contributing factor ?

* I took a couple of pix however photobucket seems to be having problems so I cannot share them.

[RXBOB]

I replaced my standard air filter with the SE high flow A/C at 500ks and was clean as a whistle. I put an external Breather on the new backing plate before install
Yeah PhotoBucket is not working Down under either so no pics ATM

[nomadmax]

What's new about venting the engine breathers into the back of the intake and into the intake stream?  That's the way it's been for quite a while. As mentioned, the only way to correct it (in my opinion) is to reroute it to the ground.

I think there was at least one article on the M8 that said the engine was vented to the transmission

[rich1]

So it sounds like the new crank vent system isn't any better than the old one if you still get oil into the air cleaner. I would find a way to vent it to atmosphere. You certainly don't want to get your throttle body all gunked up and have carbon build up on your pistons.

[twincamzz]

here is a pic of the "pooled oil" inside the intake, behind the air filter element.

[twincamzz]

What's new about venting the engine breathers into the back of the intake and into the intake stream?  That's the way it's been for quite a while. As mentioned, the only way to correct it (in my opinion) is to reroute it to the ground.

I think there was at least one article on the M8 that said the engine was vented to the transmission

What is new for 2017 is the breather assembly itself. Old part # was 2650002, NEW part # is 29400210 ( front ) and 29400183 ( rear). Supposed to be "new and improved" to keep this very sort of thing from happening. Yes, I very well may have to look into venting this to atmosphere, however with a 5 year warranty not certain I want to go there just yet.

[Ohio HD]

I guess the same question to ask as the TC motors, the oil wasn't over full after the 1k service?

[twincamzz]

I guess the same question to ask as the TC motors, the oil wasn't over full after the 1k service?

nope, did the 1K service myself & oil level was correct.

[nomadmax]

What's new about venting the engine breathers into the back of the intake and into the intake stream?  That's the way it's been for quite a while. As mentioned, the only way to correct it (in my opinion) is to reroute it to the ground.

I think there was at least one article on the M8 that said the engine was vented to the transmission

What is new for 2017 is the breather assembly itself. Old part # was 2650002, NEW part # is 29400210 ( front ) and 29400183 ( rear). Supposed to be "new and improved" to keep this very sort of thing from happening. Yes, I very well may have to look into venting this to atmosphere, however with a 5 year warranty not certain I want to go there just yet.

Vented to the intake is the same ole same ole (no matter what they call it).  Warranty be d8mned, I won't ride a bike that's vents hot oil mist into the intake stream.  A dealer would have to travel pretty far down the bulls*t path to connect an external vent set up and a denied warranty claim of any sort.

[rbabos]

Normal engine breathing will have a certain amount of oil vapor in it. Over time it has no choice but condense somewhere in the cooler exit area. In this stock situation, the breather box, with the EPA wanting this vapor digested as much a possible by the engine . That will never be avoided since vapor and condensation of vapor is a natural fact of life. Where you want this to happen as in sucking it into the engine, collecting in the box or having the exit remote are your choices. Having it external also gives one a view of how well the rings are sealing and breather function. If venting into the tb, it's unseen other then long term extra carbon build up at some point, questioned priro to that by why am I using more oil then I should.
Ron

[djl]

I think there was at least one article on the M8 that said the engine was vented to the transmission

I read that article as well but bullshit; not so.  Check the intake parts break down that FSG posted for details.

http://harleytechtalk.com/htt/index.php/topic,94659.0.html

[twincamzz]

I think there was at least one article on the M8 that said the engine was vented to the transmission

I read that article as well but bullshit; not so.  Check the intake parts break down that FSG posted for details.

http://harleytechtalk.com/htt/index.php/topic,94659.0.html

Could this be what you are referring to ? Oil used in the "precision cooled" models is returned to the oil tank ?

[djl]

Thanks, that must be it. Obviously, I didn't read correctly and missed the "cooling oil" part.

Just heard from a buddy that has externally vented the breather on his M8 and still getting a bit of oil/condensate in the throttle body.

[rbabos]

Thanks, that must be it. Obviously, I didn't read correctly and missed the "cooling oil" part.

Just heard from a buddy that has externally vented the breather on his M8 and still getting a bit of oil/condensate in the throttle body.

Wonder if that's from the valve seals and intake reversion moving it around. Does it do the startup smoke thing also? No other place for oil to enter the intake if external breather lines are used.
Ron

[SLAATY]

GM had this issue particularly bad in the early 3.6L motor intake boots. While it never did get fully resolved, we learned that the majority were caused by short trip/run time events. Those who regularly drove at least 10 mi trips avoided the issue in large part.

Could be what's happening here. Personally I'll be venting mine as always, and switching out when going to the dealer for work. Not a big deal. My service mgr. would cover me, but this avoids putting him in that situation.

[nomadmax]

I think there was at least one article on the M8 that said the engine was vented to the transmission

I read that article as well but bullshit; not so.  Check the intake parts break down that FSG posted for details.

http://harleytechtalk.com/htt/index.php/topic,94659.0.html

Could this be what you are referring to ? Oil used in the "precision cooled" models is returned to the oil tank ?

This is what I was referring to.  An article in Cycle World that has people on every Harley forum believing the engine is vented to the transmission and not the intake.

"Small details are important. In the past, if the oil was overfilled, excess oil could wet the air filter via the breather. This has now been rerouted through the transmission case."

http://www.cycleworld.com/harley-davidson-motorcycles-new-milwaukee-eight-big-twin-engine#page-10

[djl]

Thanks, that must be it. Obviously, I didn't read correctly and missed the "cooling oil" part.

Just heard from a buddy that has externally vented the breather on his M8 and still getting a bit of oil/condensate in the throttle body.

Wonder if that's from the valve seals and intake reversion moving it around. Does it do the startup smoke thing also? No other place for oil to enter the intake if external breather lines are used.
Ron

He says no smoke but, as you point out, where else would oil come from except the guide seals?  And if guide seals are letting oil by, one would expect a puff of smoke.

[bigfoot5x]

I've never worried about it. Cars and trucks have been venting the crankcase to the intake since the 1960's. Our roads have a lot less oil on them now then during the 60's. Twincamzz mentioned that he rides at freeway speeds a lot and asked if that was a contributing factor. Good question. I have noticed that there is more residue inside the air filter when I do the service if the previous 5000 miles were including a freeway trip or vacation of 1000 miles or so versus running around town. I have often wondered if it was the result of the built up pressure from running at 80 mph for 150 miles and then hitting an exit ramp. Running down the road the mist was sucked into the engine but when abruptly slowing and exiting the lower rpm does not suck in as much as freeway speed. Could be your situation if on a freeway every day for several miles.

Again, have never worried about it because even after taking a 3500 mile trip, there has never been enough oil consumption to have to add oil. To me it is a non-issue until I start showing oil consumption.

[rich1]

I've never worried about it. Cars and trucks have been venting the crankcase to the intake since the 1960's. Our roads have a lot less oil on them now then during the 60's. Twincamzz mentioned that he rides at freeway speeds a lot and asked if that was a contributing factor. Good question. I have noticed that there is more residue inside the air filter when I do the service if the previous 5000 miles were including a freeway trip or vacation of 1000 miles or so versus running around town. I have often wondered if it was the result of the built up pressure from running at 80 mph for 150 miles and then hitting an exit ramp. Running down the road the mist was sucked into the engine but when abruptly slowing and exiting the lower rpm does not suck in as much as freeway speed. Could be your situation if on a freeway every day for several miles.

Again, have never worried about it because even after taking a 3500 mile trip, there has never been enough oil consumption to have to add oil. To me it is a non-issue until I start showing oil consumption.
[/quote

Once, I did not vent to atmosphere right away. The bike did not use any oil.  Yet at 5k miles the throttle body and intake valves were all gunked up. Cleaned up the mess and vented to atmosphere. Checked again at 5K miles and the throttle body and intake valves were still clean. So just a little bit of oil mist is enough to make a mess but not enough to show you are using oil. Just my experience.

[Tattoonick]

I've got about 1,800 miles on my M8, I pulled the AC today to look for oil and it's certainly popped up in the tb and the bottom of the filter is pretty wet too. I did my fluids about 1,000 ago and when hot my oil is right at the halfway make on the dipstick. There is a bunch of grime and residue built up on the throttle plate. I'm gonna reroute this crap as soon as we get home from the trip. It'll be another 1,000 miles before I can get it done, but I'm sure it's not too big of a deal.

[motorhogman]

I just have to SMH and wonder why anyone should have to worry about a brand new machine pushing oil into the air filter box.. My 2001 did it horribly every time I ran highway speeds until I replaced the breathers and drilled the rocker supports. Why in the world does HD not correct these issues ?  Seems like a simple fix with all the brilliant engineering they have.. It's not like they give these bikes away.  $$$$$$$ 

[rbabos]

I just have to SMH and wonder why anyone should have to worry about a brand new machine pushing oil into the air filter box.. My 2001 did it horribly every time I ran highway speeds until I replaced the breathers and drilled the rocker supports. Why in the world does HD not correct these issues ?  Seems like a simple fix with all the brilliant engineering they have.. It's not like they give these bikes away.  $$$$$$$

The fix is not as simple as you think. Assuming the cyls are round and ring seal is as good as possible, a tall order for air cooled cyls, you still have normal ring gaps. These gaps allow cumbustion gasses in to the case and need to be vented. The higher the outflow the more oil vapor it will take with it and less time to condense before it can drain back as a liquid. Higher rpms per the same time frame expose the ring gaps to more combustion events which is why they spew more at higher rpms. The short area for venting from head to intake is not helping much in this case since there's no real condenser effect in play. That sponge or filter media in the breather can only do so much to keep up.  All said and done, it 's pretty normal for any piston engine to behave this way since blowby is a normal fact of combustion.  How much and how it's hidden from the owners view is what makes the difference. Out of site out of mind seems to work in most cases.
Ron

[motorhogman]

I just have to SMH and wonder why anyone should have to worry about a brand new machine pushing oil into the air filter box.. My 2001 did it horribly every time I ran highway speeds until I replaced the breathers and drilled the rocker supports. Why in the world does HD not correct these issues ?  Seems like a simple fix with all the brilliant engineering they have.. It's not like they give these bikes away.  $$$$$$$

The fix is not as simple as you think. Assuming the cyls are round and ring seal is as good as possible, a tall order for air cooled cyls, you still have normal ring gaps. These gaps allow cumbustion gasses in to the case and need to be vented. The higher the outflow the more oil vapor it will take with it and less time to condense before it can drain back as a liquid. Higher rpms per the same time frame expose the ring gaps to more combustion events which is why they spew more at higher rpms. The short area for venting from head to intake is not helping much in this case since there's no real condenser effect in play. That sponge or filter media in the breather can only do so much to keep up.  All said and done, it 's pretty normal for any piston engine to behave this way since blowby is a normal fact of combustion.  How much and how it's hidden from the owners view is what makes the difference. Out of site out of mind seems to work in most cases.
Ron

Maybe not a simple fix on new bikes.. I know there will always be some blow by. I just know that mine did it when it was new to the point oil would drip out of the ac onto valley between the lifter boxes when parked after a long highway run.. When running the highway there was always some on the side cover and seat.. I quit running over 70 mph because it was so aggravating. Dealer replaced the vents under warranty before the bike was even a year old, made no difference. After my "simple fix'  I can run 80 to 90 mph for a good 20 or 30 mi and not a drop in the air filter even with the oil above the 1/2 way mark. Top end has never been off, 98,000 mi.. In fact I can take a white paper towel and wipe inside the air inlet and get nothing at all.
I guess I just expect to much for the money.. I think they should have put that V Rod engine in Dressers or at least made it an option. That is the most impressive stock HD I have ever rode. Rented one a few years back and almost talked myself into buying one..Wife had other ideas though  ..
The older I get the more things I find unacceptable when it comes to 'Quality"   Just me.. 

[rbabos]

I just have to SMH and wonder why anyone should have to worry about a brand new machine pushing oil into the air filter box.. My 2001 did it horribly every time I ran highway speeds until I replaced the breathers and drilled the rocker supports. Why in the world does HD not correct these issues ?  Seems like a simple fix with all the brilliant engineering they have.. It's not like they give these bikes away.  $$$$$$$

The fix is not as simple as you think. Assuming the cyls are round and ring seal is as good as possible, a tall order for air cooled cyls, you still have normal ring gaps. These gaps allow combustion gasses in to the case and need to be vented. The higher the outflow the more oil vapor it will take with it and less time to condense before it can drain back as a liquid. Higher rpms per the same time frame expose the ring gaps to more combustion events which is why they spew more at higher rpms. The short area for venting from head to intake is not helping much in this case since there's no real condenser effect in play. That sponge or filter media in the breather can only do so much to keep up.  All said and done, it 's pretty normal for any piston engine to behave this way since blowby is a normal fact of combustion.  How much and how it's hidden from the owners view is what makes the difference. Out of site out of mind seems to work in most cases.
Ron

Maybe not a simple fix on new bikes.. I know there will always be some blow by. I just know that mine did it when it was new to the point oil would drip out of the ac onto valley between the lifter boxes when parked after a long highway run.. When running the highway there was always some on the side cover and seat.. I quit running over 70 mph because it was so aggravating. Dealer replaced the vents under warranty before the bike was even a year old, made no difference. After my "simple fix'  I can run 80 to 90 mph for a good 20 or 30 mi and not a drop in the air filter even with the oil above the 1/2 way mark. Top end has never been off, 98,000 mi.. In fact I can take a white paper towel and wipe inside the air inlet and get nothing at all.
I guess I just expect to much for the money.. I think they should have put that V Rod engine in Dressers or at least made it an option. That is the most impressive stock HD I have ever rode. Rented one a few years back and almost talked myself into buying one..Wife had other ideas though  ..
The older I get the more things I find unacceptable when it comes to 'Quality"   Just me..

Funny thing about the vrod Revolution is they don't use one way breathers at all. Both heads vent into a canister inside the breather and just one 1/4" hole for exit. This canister has the typical scothbrite looking disc supported on a pedestal inside. Over a season there might be a bit of misting on the bottom of the box but I've never seen liquid. The odd person has claimed otherwise but it usually works good. Damn thing shouldn't work and puke oil all over the place but doesn't. I'm normally a fan of external venting but my intake track is free of oil and no unusual carbon forming so I left it alone. I did find out if one way valving is added to the crankcase breather circuit you can pick up about 6 ponys but again, don't need it for my style of riding. Maybe I'm getting old but I've saved a chitload of money by leaving things alone.
Ron

[-deuced-]

Maybe it's not valve stem seals and perhaps it's the head breathers. Do the M8 breathers employ any one way valving? Would metal breather housings be better for condensation of gases and keeping oil inside the engine?
I'm surprised there's any problem at all with any new bike. The world has come a long way since the birth of the Twin Cam. Advancements in technology like simulation software. HD has had that real world testing ground for a few years.
I think it's pretty obvious that I'm interested in the mechanical aspects of the M8 but I don't want one and that has nothing to do with any internet reported hiccups. I have absolutely zero desire to relive the after sales experience.