The vanishing oil

Whats the deal with the oil level, this morning i checked the oil level and it was near to max, like every other week.

I started the car because i had to move it, once the engine was switched off i waited 5 mins and checked the oil level and it was now just above minimum, wheres my litre of oil gone? Im sure if i leave it for a couple of hours the level will be back where it was.

Never had this problem with other cars.

Maybe the ground wasnt level when you checked it on one of the occaisions?

After only five mins there will still be some oil hung up in the galleries and the cylinder head, too.

Nope its the same spot, Engine was cold when i started it and i let it run for a minute and drove it to the next parking space (Still level) which took 30secs and i then turned the engine off whilst it was still cold (I normally let the engine run) and waited 5 mins and checked the level.

5 Minutes when cold isn't enough time to check the oil level after running. There will be loads of oil hanging up in the head etc hat will take ages to drain down.

Its supposed to be 5 minutes after shut down at normal operating temperature. Oil level should be at max mark on the dipstick in this condition.

Checking when cold & filling to the max mark after being stationary all night is a sure fire way to overfill it.

Take it for a good warmup & check on the level 5 mins after shut down.

 

Its supposed to be 5 minutes after shut down at normal operating temperature. Oil level should be at max mark on the dipstick in this condition.

 

Oil should be at the MAX level?

 

Checking when cold & filling to the max mark after being stationary all night is a sure fire way to overfill it.

 

Surely if the oil is at the MAX level 5 mins after shutdown, then when its stone cold it will be higher than MAX or not??

Imi,

As oil heats up it grows in volume.. that's what the viscosity improvers do, try to make it thicker as it thins out.

If you have a car that at maximum on the dipstick is 7 litres, and have 6 litres of oil in the sump when its cold & has been sat all night.... then heat it up to normal operating temp and it becomes 7 with the engine off, you have the correct level when its hot (because engines run with hot oil).

If you have 7 litres when its cold (i.e. set it to maximum when cold), then heat it up & it becomes 8+ litres this will obviously be too much & may cause leaks, power loss etc

If you have 7 litres cold just after running the engine for a few seconds; with the large amount of oil hang up in the upper parts of the engine caused by the slow return of oil to the sump as it is very thick, you may end up with 9 litres when checked properly. This is 2 litres over spec & is likely to blow a seal (especially in turbo engines where crank case pressures are higher then NA).

If it is set to Max level hot after 5 mins, you'll find that when stone cold it will be about 5mm lower on the dipstick. This is the room for expansion! So when doing an oil change, fill it up with the new oil to about 5mm below max after running for a few seconds to check for leaks.

As a few of the other guys already said oil takes some time to fully drain down into the pan. On level ground with the engine up to operating temperature wait five minutes and the oil should be between the min and max marks. If you leave it to sit all night and check it cold without starting it should be at or near the max mark. Typically mine reads about 2/3 up to the max mark after 5 minutes and will go to max after about 10-15 minutes. Check it immediately upon shutdown and it is just 1/3 above the minimum line.