Oil Consumption

[Solina Dave]

I just checked the oil consumption on my '78 GL, over the past 2,728 kms./1,695 mi.
I'm averaging 1,520 kms./945 mi. per litre./quart. Does that sound about right? Or what!
Would you be concerned about anything, with oil consumption at that rate?
There's been no engine work for at least 215,000 kms./133,600 miles., and it has zero leaks.

....Dave

[Track T 2411]

About 1ml per mile... not exactly a 'check the gas and fill the oil' situation, in my humble opinion. With 133 plus thousand miles, I wouldn't worry too much. My 2 cents... Enjoy the ride!

[flyin900]

How do your plugs look? That would concern me more if they were oil fouled or showing signs of burnt on grey oil ash deposits on the electrode area.

If they look pretty normal then ride on

Just keep doing what you’re doing and checking and filling as needed.

[ericheath]

Lots of us have found that filling to the middle line, rather than the top line results in virtually no oil loss. Fill to the top and lose a quart in 500-1000 miles. Never heard an explanation as to why but it works for me.

If you’re prudent and fill every time it’s half empty, you keep adding. Live on the wild side.

[Whiskerfish]

should be zero consumption. Does your oil get dirty quickly after a change?

[desertrefugee]

I dunno, WF. At 133k miles, there will be some wear on rings and bores. Oil will pass into the combustion chamber. How much is too much? I guess it depends on the tolerance for power loss, smoke, potentially fouled plugs or the inconvenience of frequently adding oil.

[Solina Dave]

Thank you one and all. That's kind of what I've been thinking.
When I said, "it has zero leaks", that's not really true. There is a slight leak around the wiper screw, that dirties up the sight glass. It makes me nervous. But it also makes reading the oil level a problem. I find it hard to see the oil level at the half way point, and don't really start to notice it until it's past that point. By then, I may have overfilled. Who knows?
I know the mileage is up there, but it runs well. Maybe not as strong as it used too, but I can live with that. I don't have a trail of any blue smoke out the back end, so that's good. I haven't checked my plugs lately. I should do that. And the oil is quite black at change time, usually 3500 to 5000 miles. "Zero consumption!" ???
Anyway at my age , and not really being too sure how much longer the saga will continue, I'm inclined not to worry too much. I can live with topping it up. I go for a nice long ride, and then the next day, when it's cool, I top it up. No problem.
If it starts to blow blue smoke, embarrassment will no doubt force me off the road. Then I'll look at "Plan B", whatever that might be.
In the mean time, I think I'll just carry on!

Thanks again.... ....Dave

[Sidecar Bob]

Lots of us have found that filling to the middle line, rather than the top line results in virtually no oil loss. Fill to the top and lose a quart in 500-1000 miles. Never heard an explanation as to why but it works for me.

If you add the exact amount of oil recommended in the manual it will come to almost exactly to the middle of the sight glass (right where that useless wiper is). The upper mark is not a "full" mark but rather the maximum permissible level (think of it like the maximum pressure number on the side of the tire - you could under extreme conditions but it is not what you should normally do).

Why an over filled engine uses oil is simple: When the oil level is too high more oil is splashed up by the moving parts so that it can be carried out of the engine through the breather until the oil level is reduced to the correct level so there will be less splash.

[Solina Dave]

THAT USELESS WIPER!!!!
Why an over filled engine uses oil is simple: When the oil level is too high more oil is splashed up by the moving parts so that it can be carried out of the engine through the breather until the oil level is reduced to the correct level so there will be less splash.

Thanks Bob. That would make sense. I'll make sure that my oil level is at the halfway point from now on. I'll see how it goes.

.....Dave