Gilly,

Are you saying this in jest or does the dipstick tube really go to the bottom of the pan? From what I've seen in non MB engines, the dipstick tube isn't much longer than what you see, which is considerably shorter than the dipstick, which itself doesn't go to the bottom of the pan. It would take a heck of a vacuum to suck out all the oil if the suction tip isn't in contact with the oil.

Thanks,
Sixto
91 300SE
81 300SD

My preference is to change the oil by pulling the drain plug after the engine oil has had a chance to get hot. In a diesel, the high-detergent Shell Rotella oil has presumably taken up a lot of carbon particles (aka "soot") in suspension during the warm-up. So, I pull up to a stop at the front of the garage, throw the pan under the car and unscrew the plug.

Whoooosh! Out comes two gallons of pitch black oil in about 30 seconds. No chance for any soot to settle out. And a good chance for any heavier gunk in the bottom of the oil pan to get flushed out as well.

As far as the hot drain plug and oil (ooch ooch eech ouch ouch) I just take the pain......

How long does it take one of these suction devices to empty two gallons of oil?

Ken

There's a lot of discussion about getting all the bad oil out and I was thinking what about poring some clean new oil in until it comes out clean to "rinse" the engine out?

If you pour clean oil into a non running engine with the drain plug out, you might clean some of the gunk along the path the clean oil takes. But the oil won't get to very many places if the oil pump isn't running. You also won't get the full effect of oil holding gunk in suspension if it isn't at operating temperature. You're probably better off using ATF since it'll do a better job of cleaning whatever it touches in the engine even at room temperature.

How about we go back to the W198 300SL with no oil filter and 1,000 mile oil change recommendation?

Sixto
91 300SE
81 300SD

The ultimate oil system would be two 50 gallon drums of oil mounted in the rear of the vehicle.

One is full of clean oil, the other is to catch the oil from the first drum as it passes through the engine. When drum two if full, you pump it out while refilling drum one. The oil pumped out is filtered, cleaned, and recycled to be used again. In this system, you would use oil gauges to determine how much oil has been used, and how much is left.

Hmmmm, I wonder how long it would take to pass 50 gallons of oil through your engine? In other words, how many times does the 2 gallons (approx) of oil in our cars get pumped through the engine and the filter before we change the oil & filter?

And a note on the "Mercedes Method" of using the dipstick as the oil suction tube. Many boat engines are equipped with a dipstick tube that has a garden hose (male end) fitting on it for doing oil changes just like that. These engines include the popular Ford 5.0 Litre, and Chevy 350CI V-8's...

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."

Sixto:
I kid you not!
MB, to be all official about it, says DO NOT insert a suction probe into the dipstick tube. I'm not knocking others doing so, especially in their own driveways. The MB way, and the fastest way, which is important when you're on flat-rate, is to use the dipstick tube adapter. It has 2 o-rings on it and seals to the wide top part of the dipstick tube, using the entire tube essentially as a probe into the crankcase. The bottom of the tube is within fractions of an inch of the bottom of the oil pan on MOST MB engines produced in the last 10 or 15 years or so. I believe they have done oil changes like this in Europe for quite some time now.
As a test (I didn't trust it at first either, and flat-rate or not, I'm picky) I did an evacuation procedure on several MB engines and then checked the amount of oil left. On anything you'll find now, except the 111 engine, NO oil will come out, it's that close to the pan bottom. The 111 motor I think the dipstick tube isn't that close. By evacuating using the tube as a probe, I only get a quart or 2 out, so I am "forced" to either use a probe, which does come with our equipment, or I pull the drainplug. As Blackmercedes (John?) says, it works OK with the probe, just takes longer, and you can go ahead and check tire pressures or something (coffee break?) while the sucker do it's thang.
On more vintage engines, it works good back into the 80's, say on 617 Diesels, 102 and 103 engines. Doesn't seem to work the best on 116/117 engines, I pull the plug on those. On the 107 chassis, us lazy MB techs usually want to raise those up in the air to do the oil filter anyways, they all go up from the bottom on 107's, so I usually pull the plug on 107's, plus it's soooo much fun pulling the big oil drain plug on a 107 anyways!
The oil sucker we have is air operated, not a displacement pump, though. Seems to be venturi operated, creates a vacuum in this glass cylinder that holds a couple gallons, the cylinder it mounted on top of a holding tank, which holds around 40 gallons, I estimate, good for about 5-6 112 or 113 engine oil changes.
Gilly

Gilly,

Thanks for the explanation. Wouldn't you know I have a 617 and a 103. Just changed the oil of the 103 but 617 will be due soon.

Sixto
91 300SE
81 300SD

Sixto:
It is nice to have it for a Diesel engine, that much less exposure to the "liquid tar" that oozes out of the crankcase. You're looking at roughly 7 or 8 quarts being removed, so make sure you have enough capacity, the 103 of course is closer to 6 1/2 quarts.
For your own piece of mind, I would recommend the first time you change oil in this manner to pull the drain plug and make sure your equipment is doing a good job of getting all the oil out. As with any oil change, make sure the engine is up to operating temp before extracting.
Gilly

Does the Liqivac come with this dipstick tube adapter? If not, then how would I get one? Is a M104 engine from 1997 a good canidate for this method? Thank you.
Kyle

i've got the steel topsider and i'd like to try this method you have of not inserting a probe into the dipstick.can i adapt my topsider to suck the oil with your method? anybody else have any ideas?

__________________
'95 s500 (bought for wife but can't bear to share!!!) 125kms
'92 legend 180kms
'88 tbirdturbo(fantastic car-only regular maint.)120kms
'87 mustang gt(gone)
'86 tbirdturbo(gone)
'85 mustang gt(gone-but not forgotten)

Daddio and Kyle:
I'm not really sure what the Topsider or Liquivac come with as far as adapters or probes. We have gotten adapters from AGA in Bettendorf, IA, but I don't know if they would thread on to your equipments hose end/shut off valve.
Gilly

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thanks for the prompt reply.if i stretched a hose over the end of the dipstick tube(meaning that it was SUPER tight over the opening) and proceeded in my usual manner,would this suffice?or do i need an adapter?thanks again!

__________________
'95 s500 (bought for wife but can't bear to share!!!) 125kms
'92 legend 180kms
'88 tbirdturbo(fantastic car-only regular maint.)120kms
'87 mustang gt(gone)
'86 tbirdturbo(gone)
'85 mustang gt(gone-but not forgotten)

The dipstick tube that goes into the engine that comes with the LiquiVac works just fine. I'm not sure it would generate enough vacuum to not use the "probe" method.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

The dipstick adapter picture is here
http://www.fluidevacuators.com/probe.html
Scroll to the bottom of the page. I've sent them request for price and availability.

Daddio:
What you have in mind may work, not familiar with that particular piece of equipment. Try it and see, you won't hurt anything by trying it out. If it's not good enough, you'll suck air around the top of the dipstick tube and have a slow or non-existent evacuation process. The advantage to using the dipstick tube is speed, much faster than a thin probe tube. In the shop, it matters, we try to save time without really cutting any corners. For home use, it may not matter that much to do it faster.
Gilly

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