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Discussion Starter #1
Starting over a year ago I would see a loss of 12+ oz. of oil after some(not all) of my rides, usually over 400 miles. Before then it didn't use that in 6,000 miles. No smoke on startup. So I decided to look around the bike.
1. The O2 sensor is mostly black which is rich mixture vs. brown of burning oil.(Clymer)
2. I might have gone back to the OEM air filter from the K&N at the start of the oil issue. Just thought of that this a.m.
3. The Distribution hose does have the oil film at both ends of the bent hose but I do not see any puddling of oil. I have not been smelling the oil cooking on the engine. It will be ordered and replaced. I believe I see the normal crack in that bent hose.
4. When I removed the air box there was some wet oil inside all 4 air intake stacks up about 3" from the bottom.
5. When I showed the spark plugs to a mechanic friend he felt that if it was burning oil it was more #2 vs. the other 3.

My question is does anyone feel there is anything other than the Distribution hose that might be causing this oil to blow up the intake stacks? Since I am this far into her I hope to check everything that I am comfortable checking.
 

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Starting over a year ago I would see a loss of 12+ oz. of oil after some(not all) of my rides, usually over 400 miles. Before then it didn't use that in 6,000 miles. No smoke on startup. So I decided to look around the bike.
1. The O2 sensor is mostly black which is rich mixture vs. brown of burning oil.(Clymer)
2. I might have gone back to the OEM air filter from the K&N at the start of the oil issue. Just thought of that this a.m.
3. The Distribution hose does have the oil film at both ends of the bent hose but I do not see any puddling of oil. I have not been smelling the oil cooking on the engine. It will be ordered and replaced. I believe I see the normal crack in that bent hose.
4. When I removed the air box there was some wet oil inside all 4 air intake stacks up about 3" from the bottom.
5. When I showed the spark plugs to a mechanic friend he felt that if it was burning oil it was more #2 vs. the other 3.

My question is does anyone feel there is anything other than the Distribution hose that might be causing this oil to blow up the intake stacks? Since I am this far into her I hope to check everything that I am comfortable checking.
I don't want to start an oil war, did you switch brands or weights, or dino to synthetic recently?

My experience has been with some brands of oil, they seem to disappear faster than others.
HTH...Randy
 

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Discussion Starter #3
Been using Mobile1 synthetic from the beginning. Has 86,000 on the clock.
 

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More information required. Has the fuel economy changed, possibly using more fuel ? Is the engine running cooler than usual ? Is there any noticeable reduction in performance (engine output) ? These symptoms can cause the oil film to be washed from the cylinder walls, hence oil consumption will increase. I have seen car engines with EFI where the root cause of this problem (oil consumption) is in fact a faulty thermostat in the cooling system (not closing or opening too early). Engine runs cold, EFI richens the mixture because it sees the engine as still warming up, fuel consumption increases, engine output decreases oil gets burnt due to rich mixture. Not saying this is your problem but it can be possible.
 

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Discussion Starter #5
I have been seeing the temp being in the middle where it is supposed to be. Once it warms up it does not go below the line.
The power seems to be just as good as is the mpg. I have always gotten 44 to 48 mpg when riding 65 on the open road.
To me the strange thing is that it might not use oil all the time. Coming back from the MOA rally I probably went the first 900 miles with no movement in the window. Then 650 miles, some in the mountains while running at higher rpm, it went down about 12 oz.
I still want to get some suggestions about that oil up in the air inlet tubes. There has to be some reason for oil to blow up in the opposite direction of the incoming air. I do plan to go back to the K&N air filter since that is the only change I might have made before the oil loss started.
 

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the air flow in the inlet tubes is not continuous, only flows when valves are open so start stop, there is no vacuum on the crankcase breather tube since it enters the injector body above the throttle plate - if you are getting a lot of oil there it is most likely blow by on the piston rings - higher rpms will create more crankcase pressure than low rpms
 

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Discussion Starter #7
Gary,
So shouldn't there be more oil on the engine with more crankcase pressure if the distribution hose has cracks and leaks? The only oil I see on the engine is a thin dusty film running down to the reverser knob as others have said and heavy dirt collected on 'all' of the distribution hose.
 

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+1 On what Gary just wrote. I would have a pressure test done on each cylinder. I've worked on 2 LT's with the same situation and both were broken piston ring lands that finally caused the oil rings to start passing oil into the combustion chamber.

Let us know what you find.
 

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I do plan to go back to the K&N air filter since that is the only change I might have made before the oil loss started.

Stay away from the K&n filter.
Go back to the stock one.
That is where you are getting the oil in the intake stacks.


later..Randy
 

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Discussion Starter #10
So I do a pressure leak test instead of a compression test? I don't have either tool, yet, but want to make sure I understand the one I need.
I sure hope you are not correct about the piston lands.
 

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Discussion Starter #11
Randy,
I have had the OEM filter quite some miles now. The K&N has been in storage at least 12,000 miles. So, it isn't the K&N.
 

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Discussion Starter #12
Just a thought as I am not much of a mechanic. There is oil in all 4 stacks. I feel it isn't likely that all 4 cylinders have ring issues without loss of power or increased fuel consumption. However, the one commonality of the 4 stacks is the distribution hose assembly.
Am I missing something here?
 

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Ernie, what sort of numbers would you expect to see on a compression test with a broken ring land? And could you see it, or anything, if you scoped the cylinder?
 

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Just a thought as I am not much of a mechanic. There is oil in all 4 stacks. I feel it isn't likely that all 4 cylinders have ring issues without loss of power or increased fuel consumption. However, the one commonality of the 4 stacks is the distribution hose assembly.
Am I missing something here?
there is one tube from the crankcase which goes to a splitter connected to all four stacks that way there is always suction from one of the cylinders when it's intake valve is open. You need to do a compression test altho that is for the compression rings and if an oil ring has failed will not tell you much, plug color and deposits will tell you more. Also remember it's a question of the degree of failure unless something actually breaks you will start to see evidence of failure which will slowly increase as things get progressively worse.

you can buy a compression gauge, not real expensive, they screw in the spark plug hole,

Sometimes the only way to find what is worn out is to take it apart and if you have never taken a motor apart you would not recognise what was wrong.

option 1 - drive it and watch the oil levels until it fails completely and look for a used motor
option 2 - bite the bullet and have someone who knows motors pull it apart, which can be done without removing the motor from the bike.
 

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Discussion Starter #15
I appreciate the input from all that have replied.

I will be replacing the distribution hose once it comes in and keep an eye on the oil once I have everything back running. I am going to hold off on the tear down until I am more comfortable with where and if the issue is. I am going to check the compression too.

If the oil consumption continues I might have to fill the oil after dark on trips so the HD guys don't see me do it. I could tell them BMW came up with a way to eliminate oil changes, add a little per day.

Once I am back riding again I will update this thread with any new info.
 

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If it's truly burning oil in the combustion chambers, it can come from several sources. 1: Excessive blow-by into the crankcase. This causes the oily residue you see in the intake. Some oily residue in the intake is normal. On cars, a stuck PCV valve will cause high oil consumption. Your LT does not have a PCV valve, only the vent line referred to in earlier posts. It is unlikely this is the issue. 2: Bad piston rings. This will cause #1. It builds excessive pressure in the crankcase and it blows through the PCV line, carrying oil mist with it, which then burns off in the combustion chamber. Also unlikely at 86,000 miles, but possible. 3: Bad valve seals. On overhead cam/overhead valve engines the valve seals will allow oil directly into the combustion chamber when they get weak. This is where I would look, particularly if you have run synthetic oils or additives in your oils.

Do a compression check. The pressure is not as important as the consistency. If the chambers are all within ten pounds or so of each other, your rings should be ok.

Changing filters will not stop the oil you see in the intakes. It's normal, but can be where the oil is being lost if your rings are bad. Bad valve seals will have no obvious symptoms other than sometimes causing excessive smoke on start-up. Bottom line is that modern engines can burn quite a bit of oil before they will smoke out the exhaust from it. The catalytic converters just burn up the smoke before we can see it.
 

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Discussion Starter #17
Dean,
Thanks for this info.
I plan to get a compression checker tomorrow and will check to see if they are within 10 lb of each other.
 

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Remember the maximum permissible oil consumption is one liter per 1,000 km. That is a little over one quart in 621 miles
 

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Ernie, what sort of numbers would you expect to see on a compression test with a broken ring land? And could you see it, or anything, if you scoped the cylinder?
Anything greater than 10% leak down is a sign of trouble. A conventional compression tester is not going to tell you the whole story and not worth the effort in my opinion. This is true especially if you have equal wear throughout the engine and you are looking for compression values that are similar from cylinder to cylinder. You will not be able to tell if you have a broken ring land without pulling the pistons.

If you are blowing (or burning) oil in any great degree I would have to assume you have a blow-by issue. If you are getting blow-by there is one place to look. A leak-down test is the only good diagnostic short of a tear down.

Leak down testers are available for under $100 at most high end auto tool suppliers or on Amazon. I bought an OTC brand from Amazon and it works very well.
 

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Discussion Starter #20
John,
As I posted I am well below the max. oil usage, 12 oz. in 650 miles. Since She is due a 24k service I wanted to see if I could find an easy fix to the issue though.
After I get to the distribution hose replacement if I can't get her back together I may have to offer you guys a free stay at the beach, with food, to do a tech session with me. How's that?
I do plan to be at SMFR in Oct.
Benton
 
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