Oil in airbox

[Ian]

Folks,

 

I’m deep into a major service on my 04 sport. Today it was brake calliper cleaning, brake fluid change and what I thought would be an easy job, tank off and new air filter...........

 

Tank off was easy enough but when I pulled the airbox lid I found what looked like quite a lot of manky oil in the bottom of the air box, what followed next was a major PITA!

 

I couldn’t reach the bottom of the airbox to clean out the gunk so I decided to pull the trumpets out and gain access from the bottom. This wasn’t easy and I ended up taking all the rubbers off the throttle bodies, plus the intake manifolds off the heads. What I found next was even more concerning, the throttle bodies, intake manifolds and inlet tract in the heads were coated with black oily carbonised gunk. I’ve never seen anything like it before, it was nasty. I spent ages cleaning it all out with carb cleaner and rags, and finally I got it all super clean again, right down the inlet tract as far as the valve. Took me about 4 hours all together. I cleaned out the airbox as well. There wasn’t as much oil in the bottom as it first appeared, but it’s obvious that it’s been breathing oil from what was in the intake tract.

 

So, where did the oil come from? Did a previous owner overfill the oil so it pumped up the breather into the airbox. Did someone use the wrong oil which foamed and pumped into the airbox. Have I got a different problem? I haven’t actually ridden this bike yet so I don’t know if it’s a smoker, but there was tons of oil gunk in there. Never seen anything like it before.

 

Sorry no photo’s. I was too busy taking things apart and cleaning!

 

Has anyone looked inside their throttle bodies and found similar gunk?

 

Any advice appreciated.

[docc]

Yep, this can be pretty common, for several reasons.

 

How many miles on your V11, Ian?

[Ian]

9400

[docc]

So, big V-Twins do pump their crankcase a bit, yes?  Mineral grade oils vaporize much more than true "synthetics" (Grade 5, full ester base oils), but those are rare and hard to come by. Most likely your V11 has been slogging Grade 1 or 2 oils and vaporizing a lot into the evaporation/recovery system.

 

Lots of sitting-up (storage), damp environs (seashore), riding in rain, and low rpm running (also too common!) all contribute to the oil vapor evaporation accumulation.

 

My take: not abnormal/nothing "broken", but there are some things that you can do to make a difference:

 

1) Use true full synthetic, "Grade 5" base motor oil like Redline 20w-50, or BradPenn?, Amsoil? maybe Shaefer?

2) Store your V11 in a temperature controlled dry place, ride it often, and "like you stole it!" (*Tony's Italian Tune-up*)

3) See to your Decent Tune-up  and maintain your battery and charging system well. Why that? Because a good fire burns off lots of those extra, nasty things.

[MartyNZ]

So, where did the oil come from? Did a previous owner overfill the oil so it pumped up the breather into the airbox. Did someone use the wrong oil which foamed and pumped into the airbox. Has anyone looked inside their throttle bodies and found similar gunk?

Ian, I found the same in my bike. That oil and gunk can only come from the breather. Overfilling or cheap oil (foaming) can push more oil mist out the breather. Worn rings in my case (80,000km) make things worse.

I agree with Docc's remarks about oil. Something else that may help is a Roper Sloppage Plate which will reduce foaming & venting, as the oil doesn't get thrashed around as much.

[kglm]

..for that reason I make another oil trap: first tube goes 1/3 inside the can ,second goes upper part of the can to airbox. That works on my bike and no need to empty -oil seems to vapor when settled here.

 

-KG-

[Ian]

Gents, thanks for the replies and the good advice. I’ve bought motul 7100 100% ester based oil for this service. Not sure if this is class 5 or not but I’ve used motul many times before back in the UK on other bikes as it’s widely available and it’s always been good.

 

I plan on monitoring this closely once I start using the bike, because that much crud going into the motor cannot be good. If the oil and correct oil level doesn’t fix it I’ll need to find another solution.

 

I do recall actually reading something a few months back on one of the specialist MG dealer websites about problems with oil foaming in these motors with certain oils and there was a recommendation on a specific oil that did not foam. I will see if I can find it again.

 

Btw, I’m not convinced that it was condensed oil “vapour’ that was sitting in the air box / inlet tract. It looked like the product of something more like a dense oil mist.

[docc]

Yeah, man, that is the result of the crankcase evaporation system on these big block Guzzi.

 

That ester-based Motul will be great.  Regular oil changes, perfecting the state of tune. All good things!

 

That, and don't let her sit! Heat cycling ( riding her like you stole her!)  is good!

 

I mean, how far can the South'n Spine Raid be from anywhere in Virginia? 

[Ian]

Doc, where and when does the spine take place? I’m always up for a putting a few miles under my wheels

[docc]

Doc, where and when does the spine take place? I’m always up for a putting a few miles under my wheels

    (Fourteenth) South'n Spine Raid  

Weekend after Labor Day

(Sept. 7-9, 2018)

Tellico Plains, Tenn., USA

   *Get there. Bring tools*   

 

Ian, check out the threads of previous South'n Spine Raids in (click on this link): Meetings, Clubs, and Events subforum.

[Ian]

Brilliant, that’s on my 2018 bucket list now

[footgoose]

the Lodge at Tellico Plains is a small, fantastic group of modern/rustic cabins, creating the perfect base for east Tennessee- west North Carolina roads and moto adventure. It's truly a special place. The poets, rogues, and Goose whisperers who gather for the SSR, make it interesting indeed.

[Pressureangle]

I hate being a gadfly, or worse yet stupid, but well here I am...

My Sporti had a boxful of tar when I got it. During the cleanup I removed the box and cleaned it completely. I was surprised to find enough new oil back in it after the first 300 mile highway trip that I investigated pretty good; I found no trace of oil or dampness at the breather inlet nor evidence of oil on the air filter. In fact the breather inlet has a little track of white dust and rust. 
I was thinking the oil is actually blowback from the inlet valve guides. 

Thoughts? Who has checked the amount of oil in the airbox vs. vehicle miles/distance ridden/speed etc? 
If my theory is correct there should be more oil in bikes with more miles, bikes with big cams, bikes ridden with the throttle open farther more often, bikes ridden at high speeds. 

[MartyNZ]

I was thinking the oil is actually blowback from the inlet valve guides.

Thoughts? Who has checked the amount of oil in the airbox vs. vehicle miles/distance ridden/speed etc?

If my theory is correct there should be more oil in bikes with more miles, bikes with big cams, bikes ridden with the throttle open farther more often, bikes ridden at high speeds.

 

An interesting idea. If you are right, then my thoughts in post 5 are wrong.

The spine frame crankcase vent system looks to me like it should be an efficient oil separator, so your observation may explain why KGLM doesn't need to empty any oil from his extra separator bottle.

Perhaps I should keep the engine revs high, so the inlet airflow pulses are shorter?

 

KGLM, have you checked in your airbox for oil since you fitted the extra bottle?

[kglm]

Yes -airbox it´s clean. In that extra bottle theres always  spoonful or two oil. I have used Liquimoly 10/60 and last two years Motul 5100 15/50 , both acting same way.

Bike is very used ; about 165tkm

 

-KG-