My buddy just drove his V8 Vantage up from ATL. He had the dealership do an annual service about a year ago and I offered to do a bunch of stuff on it since it is aging out of the normal service intervals due to age. It is a 2009 with only 24K miles. I had planned to do Thermostat, oil, gear oil and filters along with door struts. I love working on these cars so I was actually looking forward to it since I did it all on my dads 2010 six months ago and it was a breeze. First thing I did was the engine oil, Lifted the car up on my QuickJack and cracked the drain plug, out came a very small amount of oil, far less than I expected but I just kept going. I removed all of the three sump plugs and more oil drained, but it just didn't seem like 8-10 quarts, I didn't think about it all that much and soldiered on. I replaced the filter and torqued everything down to 16-19 LBS then shimmied out from under the car and started to fill up, after the first 5 quarts were in, the lack of oil in the catch bin started nagging me so I emptied it back into the now empty 5 quart container............it barely was 6 quarts.

Now I am thinking that I didn't drain all of the oil out so I start back tracking and trying to figure out how there was 5 quarts still in the engine after the draining. My quick math made me think that there was now 5 new quarts and 4 old quarts so I do the procedure to check the oil and nope, nothing on the dipstick so I keep adding and adding until I put 9.5 new quarts in. My excellent powers of deduction now lead me to the improbable fact that this guy was literally 4, yes 4 quarts low.

He said the car drove great, no lights, no puddles and nothing underneath the car to show a steady leaking. I asked if he ever checked the oil level and he did state that he checked it a month or so after the dealer did the service and it was right in the middle but not in the past year or 7K miles.

Couple questions:
Could you actually drive a dry sump motor 4 quarts low without there being a low pressure light?
Wouldn't the pump whine from starvation?
Should I do anything else knowing it was that low for probably a while?
For him - How the hell do you not check your oil level in a year!

 

It’s not that unusual not to check the oil in the v8 vantages. Example, after changing oil at the dealer I checked the dipstick. It showed no oil on the stick. I called the dealer who says that they put in the approved amount of oil and they don’t check the dipstick. Part of the thought process is that with 10 quarts of oil, and no visible leaks, then the engine will never run out of oil. Finally checking the oil involves a process os starting the car etc. that process must be followed to get a reading. Can the dry sump system function on 4 quarts of oil? Probably, as all it needs is enough oil to keep the pump from sucking air. In that case the engine would not know the difference. With no apparent oil leaks, and the engine not emitting blue smoke, it’s unlikely that the car used 6 quarts of oil in a year. The most likely explanation it the the engine was not filled with the right amount of oil at its last service.

 

A family friend pulled into my driveway last month with a smoking engine. Her later model BMW had newish looking oil splattered over the back of the engine with wispy smoke. Taking the oil filler cap off showed no evidence of oil and, in keeping with modern convenience, the car was not equipped with a dipstick. But not to worry....the dashboard oil level cartoon gauge indicated a proper level of oil! In fact the car had minimal oil. My point being that gauges can go astray. Can’t answer your specific questions but I have to admit being stumped as to why BMW or any other manufacturer would design out a dipstick.

 

Checking the oil level in these cars is really tricky. Did you follow the instructions on the sum tank every time?

 

Idle at 1500 for 20 seconds, wait 30 seconds then check. Everything makes sense that it was low, if it wasn't I don't know where the oil would have been hiding. I checked to see if his oil light worked, it does on start up, but maybe a bad sensor? Would a V8V with half its oil missing not illuminate the oil light?

 

oil light would come on for low oil pressure, not low oil level

 

If memory serves, the engine should be run at 2000 rpm (rather than 1500) for 20 seconds, though I doubt there were 4 quarts of oil hiding in 500 rpm.