M. Requin

After doing an oil change today I decided to take a look at something that has been bothering me. An oil change or two ago I installed a ballcock sump drain valve. Very convenient to be sure, but I noticed that the bottom of the valve orifice seemed to be quite a bit higher than the bottom of the sump (interior) and wondered how much oil would be left in the sump after draining it. Today I measured it, and there was 19 (corrected) ounces left after draining the oil through the ballcock. To me that seems like a lot. Say I own the car another 10 years (ever the optimist) and change the oil once a year, driving an average of 7K miles/yr (now that's really optimistic, given my age, but 7k is the running average so far), then based on annual oil changes it looks like I end up with a pretty polluted crankcase at the end. The regular oil drain plug went back in. What do you think?

Hey_Allen

I was thinking similar thoughts, but from the side of using a top side oil extractor.
I'm currently doing one or two from the top, and then draining from the oil pan on the next (with my VW, haven't needed to drain the 928 yet...)

NoVector

Greg Brown mentioned it last year. See: https://rennlist.com/forums/928-foru...l#post15141538

GregBBRD

Although I'm not very "strong" in my opinions about these "drain valves", they suck.

Anyone that can't pull the stock drain plug and needs a silly lever operated drain plug to change the oil (part of the oil) every 7500 miles, should go to Jiffy Lube and let them handle the job.

Other than that, no opinion.

SwayBar

You can jack the passenger-side of the car up and you'll get most of the oil out of the crankcase - with or without a fancy drainplug.

Christopher Zach

Jiffy Lube can't do it, car is too low.

That said, it's a lot of oil and it comes out fast. Better have a deep and low bucket. :-)

M. Requin

Right, thanks all for pointing out that the discussion had already been had, I either missed it (or more likely) disremembered it. My only addition is the quantity- over half a quartnot drained/changed! And I've been "pulling stock drain plugs" for over 50 years, so I didn't need the valve, I just thought it was interesting It wasn't.

FredR

When you have a lift and professional kit to catch the oil no point in fitting such.

When one operates off jack stands of most of us DIY hacks do then the valve is a very useful aid to help avoid a 20W50 shampoo in cramped space! Once the oil is drained very easy to remove the valve to get the rest or as I have done with my DIY lift bars simply drop the drivers side a bit lower to get a decent chunk of the incremental amount out.

hacker-pschorr

Then get taller jack stands........

FredR

Did last week- new Chinese Souk opened close to my home- got two pairs of beefy 6 tonne stands for about $60.

Will still use the valve though.

GregBBRD

We just defeat one safety catch on one side of the lift and lower away. At about 20 degrees, everything drains out.

Cal OSHA frowns when they see us doing this, but can't find a specific section to fine us....

worf928

How many ounces of oil are left in the cooler lines, oil cooler, heads, and galleries?

Or, in other words, how many quarts of oil does a *bone dry* 928 need to get the level into the dipstick window (including one start/idle/stop cycle.)

If you are worried about a few ounces of oil left in the pan, you probably don’t want to know the above answers...

Captain_Slow

Oh snap! hahahaha. So true.

GregBBRD

This doesn't sound like you, with your attention to detail. Did someone hijack your name and password?

NoVector

In fairness, Greg also mentioned in 2012 that he sees a lot of stripped drain pans: https://rennlist.com/forums/928-foru...ml#post9513464