Check valve in full flow system

My external oil cooler is situated higher than where the oil line enters the engine. When the engine is shut off, I'm thinking all the oil in the line from the oil cooler to the engine will drain down into the main gallery.
So every time I start the engine, there will be a delay in the oil reaching the engine.
I'm thinking about installing a check valve where the oil line from the cooler enters the main gallery - that way the line from the cooler to the engine will always be "charged" with oil.

Any thoughts on this will be appreciated.

sure, but wouldn't you need two check valves, one on the supply and one on the return?
Or if you wanted to shorten the empty portion of the lines lines without a check valve
you could raise the line before and after the high mounted cooler forming a "trap" of sorts
to retain a "full" cooler but empty lines. Truth is (imho) I think any empty line refill time
is not an issue don't worry about it. The thing I would worry about is when and how you
check your oil level. Is it after your oil has all settled back into the case. If so your running
less than the "designed" amount once you've started your engine and filled your external lines and coolers. You have to make sure that your indicated "ok" level is checked with your whole system filled. A well thought out low mounted cooler system is best, no drain
back or questionable oil levels.

Bruce, the lines that go into the cooler, enter/exit the cooler at the top, so the cooler is always full of oil.
You bring up a good point about oil levels - maybe a check valve at the pump outlet would be a good idea.
Where else can the cooler be mounted safely so it will be lower than the return line to the gallery?
Thanks

I just crank my engine for a 10 seconds or so before pumping the throttle and starting it. In most cases I can get the oil light to go out before it starts. Also, it shouldn't be an issue unless the car has been sitting all winter or something. It you drive your car regularly a film of oil should remain on all the parts.

Also, the problem with check valves is they can add a restriction to the oil line creating back pressure. I'm not sure if that is too much of an issue for VW oil pumps or not. Anyone?
Ron

I go along with Ron. My oil pressure comes up to quickly to worry about it. Check valves have been known in some rare cases to crud up and stick closed and we know that wouldn't be a good thing.
Would it be possible to put 90o elbows on the cooler and arc the lines in a high loop to prevent drain back?

BD

i think everyone is saying "don't worry about it".
k.i.s.s= keep it simple @#%$ (no offense intended).
All of my cars run on neglect (I'm a mechanic after all, a plumbers pipes always leak.

But Gordon my point with the oil levels/drain back/operating levels is valid. Many a
person changes or adds oil to the indicated level on the stick and forgets to recheck
or add (if needed) after an engine run/leak check. After market (added) Coolers, lines all get filled and now you don't have what your supposed to have in the case, Seems
obvious but people make mistakes all day long.
I was watching my oil being changed on my saab from the comfort of a coffee lounge
at my local speedy lube (remember i'm a mechanic) when i noticed a large pool of oil forming on the floor around their "mechanic's" feet. Thats right the drain plug was in his
tool tray. This is a guy who does this all day long so anyone can forget to think thru
something as simple as an oil level check.
another oil story. my brother inlaws twin volvo turbo diesels on his 47 ft boat failed in
the 1sy year of ownership. "professionally" rebuilt by volvo "trained" mechs, after reinstall
they filled the engines with the required 6 gals/oil. What, no oil on the dipstick??? Lets put in another 6 (sounds good?). What, still no oil on stick??? Lets start them up. oil everywhere and shooting out of every vent, pipe and filter. They still didn't get it.
They had crushed the bottom of the oil pan against the dip stick tube isolating it from the
oil. what beauties.--it can happen and does-bruce

Gordon, I'm not sure if leaving 3/4 of a quart of filthy oil in the case is a good idea.
After 3 or 4 oil changes, you've got some seriously contaminated oil in there.

Gordon,

How could it not get worse each year? After your first oil change, you

David; remember it all comes out "in the wash"; some of those particles get redistributed in clean oil every time you change it every 3,000 miles plus you always end up throwing most away and replacing with clean oil. To tell you the truth, I don't think it really hurts, especially when you have a full flow system such as Gord's.

Arrghhh!

BD

You're absolutely right, Dave.

Put those check valves in to prevent drain-back, and while you're installing them, get a couple more fittings so you can remove those where the cooler attaches to the engine to temporarily install a pump or something to flush the cooler and lines whenever you change your oil.

Better to be safe than sorry...

What happened Gordon? Did your lawyer advise you that you could be liable if something bad happened to someones engine and their oil was to blame? If my memory is correct, you have a great deal of experience with engines and oil etc.
Ron

Yup, I do, Ron.....

I just realized that DaveD has a much better idea of what's going on in his own engine than I and should use his own judgement, that's all...

Lets try this, make a glass of Chocolate milk with lots of syrup(good and dark). Then pour out all but a half an inch. Refill the glass with fresh milk. See, it's virtually all white milk. Should be the same with the oil. It gets diluted and then filtered out more. It should stay this clean oil change to oil change.

BD