Burning oil

[crzyjarmans]

Ok. I've had my fj now for about a month and found its burning oil, no visible smoke or signs of a leak, can anyone tell me where to look, or what is causing this thanks

[Steve_in_Florida]

Shawn,
I'm in the same boat on this one.

On longer rides, I was having to add oil to keep it at the full mark.

Pulled the tank to sync the carbs, and found five of the eight valve cover seals had evidence of leaking. Replaced them recently.

I have heard that the cam chain tensioner gasket can leak; It's located in the middle of the cylinders at the rear of the engine.

If there's no external evidence of a leak, then the next likely place are the valve seals. Are your spark plugs oily at all?

These points are what immediately jump to mind to me. Experts will join the discussion soon, I'm certain.

I will be interested in hearing other opinions on this.

Steve

[HARTLESS]

How much are you losing? And have you changed the oil recently since you have had it?

[hein]

Do a leakdown test.

[ribbert]

The FJ's are prone to weeping oil around the valve cover grommets and gasket but even if really messy it is unlikely to cause oil level to drop. You need a substantial leak to see oil disappearing from a motor. Oil pooled around the plugs, running down the front of the motor, leaking onto the floor, sprayed back over the bike etc.

If it was that bad you would have noticed by now.

The weeping most common from the top end, even if widespread, is just that, weeping and not likely to affect oil level.

How much oil over how many miles are we talking here.  That might help narrow the possibilities.

When checking the oil was the bike on dead flat ground both times? Was it checked by the same method? Do you know it was full to start with?

Noel

[aviationfred]

I have had my 1200 for a year. I had oil slowly weeping from many places, valve cover grommets, valve cover gasket. The rubber gasket for the silver center piece of the clutch cover. I was loosing a quart in 400 miles. The big thing I noticed was a lot of smoke from the muffler on cold start ups. My suspicions were worn valve seals. I am in the middle of having the head rebuilt. All 8 of the exhaust vlaves show sign of bad valve seals.

Fred

[crzyjarmans]

thanks to all... Cant see any visible leaking, anywhere on the motor, Ether on top, side, or Bottom, the same with smoking, I don't see any smoke at first start up when motor is cold, nor while riding, On how many miles?, Id haven't keep count, but I would have to assume around 500-550, in that range and about 3/4 of a quart

[Steve_in_Florida]

My `92 FJ was consuming approximately a quart of oil every 1,400 or so miles. I was able to monitor this on my Iron Butt ride this past November. Prior to that, I had taken another ride one day (~450 miles) where my oil light came on about 2/3 of the way through the route, and I added about half a quart.

I do keep a close eye on my oil level, so when it does change, I know about it.

However, I haven't noticed any drips, puddles, weeping (aside from the valve cover seals I just recently replaced), or smoke from the exhaust.

I'm really not sure where mine is going, unless it's coming out the exhaust when I'm riding. No one has mentioned anything to me, but I usually ride alone. I haven't seen any other evidence.

A mystery!

[Steve_in_Florida]

Do a leakdown test.

Thanks Hein,
I am planning to perform this and a compression test in the near future.

[Dan Filetti]

Cant see any visible leaking, anywhere on the motor, Ether on top, side, or Bottom, the same with smoking, I don't see any smoke at first start up when motor is cold, nor while riding, On how many miles? I would have to assume around 500-550, in about 3/4 of a quart

I'm really not sure where mine is going, unless it's coming out the exhaust when I'm riding. No one has mentioned anything to me, but I usually ride alone. I haven't seen any other evidence.

Logically, in both of these cases it's coming out the tail pipe as burnt oil, in small enough quantities that you're not noticing it.  -Perhaps under hard acceleration when you are least likely to notice it.  Do either of these bikes smoke when revved to near red line, in neutral in the garage?  Either way, in both cases I would check valve clearances unless you know they were recently in spec.  Then, as was mentioned, I'd do a leak down test to determine whether the rings are worn. 

Dan

[mr blackstock]

G'day,

I noticed my bike was going through some oil, but according to a motorcycle magazine "doctor" 1 litre per 1000kms is with acceptable for old air cooled bikes.

If you cannot see any oil puddles, and you are not blowing smoke, check the crankcase breather to airbox intake pipe, this carries a lot of oil mist back into your carbs and engine as a way of reducing your emisions.  My breather's pipe had hardened, so I disconected it and installed a crancase breather air filter.  It works well and gets replaced occasionally, but it gets very oily!

cheers, Gareth

[Dan Filetti]

I noticed my bike was going through some oil, but according to a motorcycle magazine "doctor" 1 litre per 1000kms is with acceptable for old air cooled bikes.

Gareth,

I reject this idea.  I had an Audi dealer tell me the same damn thing.  "Acceptable" my ass.  I sold that A4 pig with with 45K miles on it, that was burning 1 qt every 1,100 miles and bought a Honda, and have owned Hondas only, since.  My Pilot has 160,000 miles on it and it has the same amount of oil in it at 5,000 miles, as it did when I changed the oil last.

Air cooled motors, assuming no abuse (sitting in traffic, not moving air across the head) should be able to do the same thing, burn little to no oil, seems to me.

Dan 

[FJmonkey]

Air cooled motors, assuming no abuse (sitting in traffic, not moving air across the head) should be able to do the same thing, burn little to no oil, seems to me.
Dan 

+1 Dan, it is blowing past the rings or not....

[mr blackstock]

G'day,

I will admit, 1 litre per 1000kms does seem excessive, but this magazine bike "doctor" seems to know his stuff.  My bike does smoke a little on start up, but nothing after it's warmed up.

What oil consumption do others here get?

cheers, Gareth

[crzyjarmans]

Ok, just tried the revving motor to red line while in N., and still see no evidence of smoke, Just a missing puzzle piece, I would think 3/4 of a quart of oil in 500 miles or so, would be easy to diagnose