pump for oil change?

Not a good idea (IMHO) for at least two reasons: First, you really should remove the bottom plate and look at, and clean the screen from time to time. (There probably won't be much to look at if you use a proper full-flow and filter system, however.) Second, poking a hose down there might disturb any junk sitting at the screen and put it back into circulation for a little while, and that's a bad thing.

Forget it, the pump can't pick up the heaviest particles and the "muck" from the bottom of the oil pan. The first couple of times it may not hurt (assuming you started with a clean engine) but with time the situation gets even worse, when the bottom crud is *never* removed. It starts to pile up. Our aircooled engines allow outside air (and impurities in it, such as dust and dirt) to get inside the engine.

Modern car engines are closed from the surrounding environments, more or less. Plus they have oil filters. Much less of a problem there.

Still, I would not use an "oil change pump" on new cars either. The heaviest junk is at the bottom of the case, and the drain plug is at the lowest point of the oil pan. The pumps can never go that deep to suck out everything.

Change your oil when the engine is warm, open teh fill cap before removing drain plug. This way you get maximum flow, which brings out as much of the heavy particles as possible from the bottom of the case.

Best "junk" I found lying at the bottom of an aircooled VW engine case, was half a piston... :) (All 4 pistons in the engine were intact, so it must have grenaded at some point of it's life, and whoever "fixed" it, never bothered to crack the case open... )

Jan

Odd, but I haven't experienced any bad heavy gunk at the bottom of an engine since switching to synthetic and semi-synthetics starting about 20 years ago. Maybe I change the oil too often.

BTW - I began using an Amsoil filter just yesterday. Before that it was the big orange can. It seems that I read slightly lower pressure at cold start-up. Perhaps the built-in pressure relief is making a difference already. What do you think? Bad guess?

----------------------------------------------------

Would you believe a pair of sun glasses?

As for oil change pumps, if it's a question of sucking it out versus not changing it, I pat them on the head and urge them to go for it... although most of the suction hoses won't fit down the VW dip-stick tube.

The engine contains 2.5 liters of oil (same as the tranny). That's about 85 fluid ounces. With the engine warm, see how much oil you can suck out of the thing.

No oil change provides a perfect replacement of all of the old oil; there is always some residue (and lots of crud) remaining inside the engine. If your sucker is able to remove at least two liters then you can probably gain some benefit from such a system but only when compared to not changing the oil, and only then if you will change it more frequently then spec'd. This latter need is dictated by how much of the oil you manage to suck out of the sump.

-Bob Hoover

Better/finer oil filtration. The oil is not just flowing through the filter lickity-split and not being filtered very well. Are you also using new/different oil than you were before?

To respond via e-mail, simply take the, "REMOVEXX" out of my return e-mail address.

How interesting. You are telling me that the AMSOIL filter is inferior to the FRAM orange can, is that correct?

On Tue, 22 Jun 2004 18:57:46 -0500, snipped-for-privacy@nix.nix (one_of_many) ran around screaming and yelling:

he is saying the opposite mr. one....the amsoil filter has finer and denser media therefore it is harder to force the oil through, resulting in a slight pressure drop... JT

Okay. I guess I was not clear, either. I should have written that with the Amsoil filter, cold startup pressure is 5 pounds lower, which might be due to the better internal relief valve. Or something else. WTF - it's still

55 pounds hot at speed and 40 at hot idle. I'm happy.

Thanks.

The ones I saw were too large of a diameter to fit in the dipstick hole.

Doesn't sound like it would do as good of a job as draining it as usual.

I have a by pass oil filter like the one at madirect.com or

1800luvbug.com or The Real Source. You substitute your oil cooler flange, 1971 and later only, with the oil filter mount. Hold it, hold it, I can hear you all now. "This is not the way to go! A full flow filter is the only way!" But so what, at least I never have a high pressure filter blow out when the oil is cold and thick. I have had no problems with it. Anyway, to get back on topic, my oil strainer never gets dirty, but I remove the sump plate twice a year to inpect and clean it. All the rest of the oil changes I just remove the drain plug and change the bypass oil filter. It is really easy. I do not even have to jack up the rear since my rear coil over shocks keep the height up. I change my oil about every 850 miles or at least every 3 months.

These oil recovery pumps are common and have been around for some 30 or years in the boating world. It's the only way to recover oil out of an I/O boat engine where you just can't get down in the bilge due to the tight clearances.

As far as the bypass filter; I have to wonder how messy a job that is with the angle the filter sits at. And I would hate to cut up an OEM german shroud to make the mod. I suppose it's an option if your just modifying an existing engine.

But for those tearing into a case, the proper full-flow is the way to go. And a 500lb burst filter (such as the HP1) will eliminate any risk of cold pressure spikes. I buy Fleetguard HF6107 which are the same spec as Fram's HP1 but much cheaper where I work.

RT