I changed oil and filter yesterday.
After draining the oil I put in 8 quarts and checked the level expecting it to settle and be a bit short of enough but it seemed kind of high, right above the top mark on the dip stick, just barely registering above the notch.
I took it for a drive around the block,( barely hitting 2000 rpm just in case it was too full) and parked again to check it.
I noticed during the drive the pressure didn't dip from 5 bar like it used to when I would let off throttle and idle as I coasted to a stop sign.
It used to go down to around 3 bar but this time it barely showed signs of dipping.

So I let it sit over night and right now, stone cold, it is at the top notch, wet to the top of the 'V' of the notch. I'm guessing I didn't get all the old oil drained out, I thought I was on level ground but my driveway has a bit of a camber to it (it was poured by a NASCAR fan, apparently he likes replicating short tracks )

Should I loosen the drain plug and let a half quart or so out or is the top of the notch still within a safe level?

 

yes, you can drain some out.

 

If it's just a tiny bit above the mark -- from your description it sounds like < 1mm excess... you can just drive it and it will get consumed or leak soon enough. You really should check it hot though, a couple minutes after shutdown, and under those conditions it may be between the marks.

 

One way to drain some out without making toooooo big a mess, is to pull the oil filter, dump it out and reinstall it.

 

Thanks guys. I went ahead and loosened the drain plug and took out around 4/5ths of a quart. Checked it and it was just below the halfway mark.
I can't be too careful with this because the previous owner cut the dipstick tube, removed X amount of tube and installed a brass T compression fitting to give access for the oil return line of the supercharger.
So, assuming he made his measurements and cuts in the right place my tube is still the same overall length and holding the dipstick in the right place

I know, not a great arrangement, I have a replacement tube but haven't decided how to return the oil to the pan or even if I'll keep this supercharger so I keep putting off the decision. I guess the wise thing to do is remove the modified tube and compare it's length to the replacement to find out if my dipstick is reading true.
There are signs of oil around the brass T so I'm putting off pulling the tube until I come up with a better way to return the oil....

 

The usual fill amount with filter is about 8.5 qts. The fact that the dipstick tube has been altred throws things into question. Best to get a stock tube and make sure the altered one is the correct length.

Oil pressure will not start to fall from 5 bars until the oil is warmed up, so I'm not sure you saw anything abnormal when it stayed at 5 bars as you drove around briefly.

 

did you fill the oil filter with oil before you installed it?
You should do this to ensure that firstly the pump does not intially pump air and secondly that you can get some strange effects if you do not do this...

Marton

 

So what happens with a qt extra? My old Mustang has a handy feature where it quickly leaks out if overfilled.

 

Yea, I filled the filter as much as I could without having it spill when I installed it, probably about 3/4's full. I also removed the fuel pump relay and turned the engine over a bit before I started it, actually it did fire briefly, I guess it had enough fuel pressurized in the rails to turn over but it died immediately, but then I let it crank for a few more turns to help move the oil.

 

you should have atleast 8 qts in your engine , if it reads too full then your next step is to verify the dipstick length