Burning oil?

[Vsekvsek]

I guess my 89 burns some oil. Seems like every couple hundred miles I get the red oil light. Then I wait til the bike is stone cold and sure enough the oil level will be just below the sight glass again on flat ground on center stand. I will fill to 3/4's full with engine cold. Then repeat cycle in another 2-300 miles. My riding is primarily freeway commuting. I rarely get it over 4 k on rev limiter. I lug it. Bike has 41k on odometer. Thing Runs amazing. Never see any smoke on start up or under loads running down freeway. No oil leaks. My mechanic friend tells me "ah hell just keep oil in it and ride- dont worry about it"

opinions?

[Arnie]

Your friend is probably right, but if it worries you there are a few things to lengthen the time between top-ups.

Fill the bike a bit more, just to the top of the window.
Check that the crankcase vent hose is properly connected to the airbox or has a reasonable length before the filter (if your running pods)
You may have ring lands that are a bit sticky, take it out and run it hard for a while.
Replace the valve stem seals

[Pat Conlon]

When I had 160k+ miles on my FJ (before the rebuild) she was using oil on long freeway rides.
Jon Cain suggested that I try Red Line Oil, a ester based synthetic oil.
I did and it worked. Oil consumption dropped. That stuff did not burn off like other oils I've tried.

Good thing too, 'cause that shit was expensive...but worth it.

[Fj.itis]

When i refreshed my top end i think i got sent 2 compression rings the same, the second one has taper i believe but mine where exactly the same.  So for the first 600 km i lost 600 ml of oil even though i had 170 psi in all cylinders, instead of ripping it back down i tried an oil additive to see if it would fix it. As of today ive done another 1000 km with not a drop lost, got lucky i guess. I used about 300 ml of this stuff at the time and now when warm cant here the starter chain rattle even at low revs.

[fredsone]

It has been a while since I fiddled with an fj so i cant remember what the breather is like...
But, am I wrong in thinking that a partially or completely blocked breather can cause increased oil consumption? javascript:void(0);

[Pat Conlon]

Doubtful, the crankcase breather tube is fairly large in diameter. For those with the stock airbox, it runs from the top of the right side crankcase to the underside of the airbox, allowing the oil vapor to be recirculated back thru the engine.
The only way this tube could be blocked is if you had a mouse nest in your airbox....which has reported to happen.

[freezer]

My 89 3cv uses about half a pint of 10-40 mineral oil if ridden hard every hundred miles so i use this top up method start the engine run for about two to three minutes then top the oil level up the the top of the sight glass, this helps the low level light problem i don t mind running a total loss system as it keeps the oil fresh
PS  i always start the bike upright never on the side stand just in case

[simi_ed]

Total loss oil system?  Does that mean you're not changing your oil?  That's a bad idea!  The contaminants still remain behind.

[Mark Olson]

I guess my 89 burns some oil. Seems like every couple hundred miles I get the red oil light. Then I wait til the bike is stone cold and sure enough the oil level will be just below the sight glass again on flat ground on center stand. I will fill to 3/4's full with engine cold. Then repeat cycle in another 2-300 miles. My riding is primarily freeway commuting. I rarely get it over 4 k on rev limiter. I lug it. Bike has 41k on odometer. Thing Runs amazing. Never see any smoke on start up or under loads running down freeway. No oil leaks. My mechanic friend tells me "ah hell just keep oil in it and ride- dont worry about it"

opinions?

check the crank seal at the sprocket, with no oil leaks visible and no smoke you may have a automatic chain lube situation.

wind the engine up and decelerate a bit once in a while this will keep the rings healthy.