Oil usage

[Rudman]

I drive an Opel Astra. Every 500 km I have to add 500ml of oil. Now the car did leak oil on the sump but I fixed that by re-torqueing and replacing some missing bolts. What I can’t understand is why it is still using oil. The car doesn't blow out any sort of smoke at all. After I fixed the sump leak it was not leaving oil on spots I stop anymore.

Can it be that oil comes out of my sump while I drive? Or is this just the amount of oil the car uses?

 

[Porker]

That sounds like a fair amount of oil. There are basically only two ways you can loose it - either by burning it or leaks. If you were burning it I would expect to see smoke especially when the engine was under load. If you can't see a leak maybe you are blowing the oil out somewhere when the engine is running. I have seen cars loose oil from the dipstick hole due to the pressure in the sump. Are there any fresh traces of oil around the engine after a run?

 

[david and julie]

You don't say what type of engine you have but I believe there are bad oil consumption problems with the DTI 2.0 diesel models.These engines are fitted to Astra, Zafira and probably other models too.

 

[Rudman]

Its a 180ie 16v ecotec motor. Its got 160000km on the motor so far. There is no leak around the dipstick. And no traces of smoke at all. I have always looked after the motor and changed the oil every 5000km i really cant understand the sudden usage

 

[david and julie]

As porker say's if you can't see leaks it must be burning it.

Sometimes you don't notice it when just looking in the mirror, you will get a better indication with someone else driving and you following. Especially if you do it in the dark, the blue smoke stands out like a sore thumb with headlights.

 

[pipme]

The old test, find a steepish, longish hill, drive down it, getting up a fair old whack at the top, halfway down, change down a cog, no braking, leave her on overrun as long as possible, then accelerate away, look for the smoke now !!
Should have created a near vacuum in the cylinders, which, if possible, will suck oil into the bores past piston rings and valve guides / seals.
In the old days before the sealed systems of today, a broken piston ring could manifest itself via oil being blown out of the oil filler cap, perhaps you should check the cam / rocker cover breather ... to air cleaner / inlet etc see if hugely oily, and operating correctly.
As has been said there are not many places for oil to go ... 0.5 L is a lot I think.
It is possible that :-
Missing sump bolts = bodge job at some time ... Main dealers have all the bolts and washers required, cannot imagine any garage leaving bolts out, unless by accident ... I guess this what one pays for. So 100K miles with some bodging ???... . There is no magic, compression test will reveal problems.
P