Changing engine oil on a W124

[Uberwagon]

Personally, I think you'll always have some bits left in the sump whichever way you do it. The only way to get it all out would be to remove the sump.

Not to be cavalier about it, but the Oil filter should take care of any deposits. As long as you change it regularly you should be fine.

6 years doing diesel engine test and development in a laboratory and 4 years in Generators, ship engines etc say otherwise.

An easy way to prove the theory.

Pump your oil out straight over a drain pan through a white sheet.

Now do the same while draining it from the sump plug.

You are spending money to do a worse job imo.

Dave!

 

[Number_Cruncher]

In practice, there's nothing inadequate, or improper about sucking oil out.

I would be prepared to be convinced otherwise if independent, peer reviewed evidence were shown that sucking oil out resulted in a significantly reduced engine life in motor cars.

For most of us with MBs, engine life is the least of our concerns anyway!

 

[grober]

I have given up limbo dancing thank you.

It may be of interest to know that the main dealers of several manufacturers change engine oil this way. i.e by sucking it out through the dipstick hole. Many inboard marine engines also use this method since its impossible to access the engine sump cos the bottom of the boat gets in the way.
On the other hand if you have a Smart!---its the only way--- http://www.evilution.co.uk/index.php?page=modpage&id=230&men=servicing
There is lots of discussion about the relative merits on the Mercedes shop forum. http://www.mercedesshop.com/shopforum/showthread.php?t=179353&highlight=topsider
You can get a couple of hours reading by typing in TOPSIDER ( metal can equivalent to the Pela) in the search box.

Perhaps the clincher is if you have ready access to a lift or inspection pit where access to the underside of the car/sump is relatively effort free then draining has a lot to offer. If you don't and many DIY mechanics don't, then a Vacuum extractor is very useful. Used properly its a lot less messy than draining the sump. With care you could do it wearing a suit and a pair of disposable gloves tho I wouldn't recommend it . Since exposure to waste engine oil is a cancer risk (Scrotal cancer if you must know ) minimising your exposure is perhaps a good thing. Each to his own I guess.

 

[scooter]

i would use a trolley jack with a plank of wood to hold the weight of the sump cover

 

[SilverSaloon]

i'm sure the ONLY reason Merc now sucks it out is to save time (and charge the same amount as they used to)

Draining has to be better or atleast the same so for the hassle i would drain every time! its not much hassle or expense to drive the car up on some ramps and drain it.

anyone who changes their own oil would benefit from some ramps anyway.

saying that, i've only done oil changes a few times so what do i know

 

[Number_Cruncher]

>> Draining has to be better...

Why?

Show us some **evidence** of premature engine failure because of using a vacuum pump to remove the oil.

 

[SilverSaloon]

>> Draining has to be better...

Why?

Show us some **evidence** of premature engine failure because of using a vacuum pump to remove the oil.

i have none, just my opinion.... i personally would rather drain it out and leave it draining for a while.... that way i would know there is nothing else to come out, whereas if you suck it out you may not get it all?

i guess i prefer letting gravity do its thing...

 

[Number_Cruncher]

>>that way i would know there is nothing else to come out, whereas if you suck it out you may not get it all?

Oddly enough, in terms of oil volume, the reverse is actually true. You get more out via the dipstick tube than you do via normal draining.

 

[jaymanek]

i dont believe in sucking the oil out... its a rubbish method IMO...
I always warm the engine and leave the oil to drain for up to an hour..

You cannot possibly get all the rubbish out by sucking it...

Unfortunately though this is the only way with some cars

 

[Ian B Walker]

I always take the sump plug out when changing oil. I also turn the engine over a couple of times to purge the pump (no ignition I hasten to add). I have little faith in sucking oil out, its alien to me, but I am an old f.art, trained in the old fashioned ways

 

[Howard]

Since exposure to waste engine oil is a cancer risk (Scrotal cancer if you must know ) minimising your exposure is perhaps a good thing.

Just done this on one of the endless H+S courses i have to attend.

Scrotal cancer rates were seen to be higher in mechanics , this was because people were draining oil and working on engines in bare hands , then ( without cleaning their hands ) going for a wee ... effectively rubbing engine oil onto their privates a few times a day.

You won't get scrotal cancer specifically from just being around used engine oil. If you were to rub it on your nose every day , you may well get nose cancer for example.

 

[Dieselman]

Maybe grobers been saving money by not buying aromatherapy oils..or other such 'things'...

 

[spock500]

You can buy the larger 6.5litre Pela unbranded for about £40 ish -

When I first used mine I must admit to being a bit sceptical so sucked out all the oil (7 litres) then undid the sump bolt anyway, not a single drop came out, not even off the bolt!

The suction method also allows you to suck the oil form the filter housing which would normally remain

 

[steptoe]

In practice, there's nothing inadequate, or improper about sucking oil out.

I would be prepared to be convinced otherwise if independent, peer reviewed evidence were shown that sucking oil out resulted in a significantly reduced engine life in motor cars.

!

I'll play your game - You show me an independent test that proves sucking out the oil through a pump is more efficient than draining it through the sump plug.

You can't beat gravity.

 

[Number_Cruncher]

>>an independent test that proves sucking out the oil through a pump is more efficient than draining it

Ah!, I don't really need to go to such lengths. All I need to show is that sucking oil out doesn't lead to a much reduced engine life.

Oil has been sucked out of engines, particularly MB and BMW engines for years - the first time I saw it done was in the late 1980s. It's not a new thing by any means.

Engine life for MBs isn't such a serious issue - how many threads do we read of people asking about crank re-grinds, acceptable running in procedures for new piston rings, which brand is the best for aftermarket pistons......

Not many!

Therefore, oil, oil changing regimes and methods, longlife engine servicing intervals are all non-subjects. Exactly what you do doesn't really matter, as long as you meet, or exceed the manufacturers recommendations.

Oil changing is one of those odd things, that because it falls into the range of capabilities of even the dumbest DIYer, there's a whole silly mythology built up around it. At least we aren't as daft as the yanks, who still do 3000 mile oil changes!

 

[Dieselman]

At least we aren't as daft as the yanks, who still do 3000 mile oil changes!

that's because of the-yr high Sul-fer petrol and s**t oil..

 

[c240yaz]

Definately NOT recommended for changing your ATF on an auto box.

It will suck any shrapnel up from the filter outer, displacing it in the last places you want it to deposit. defeats the purpose and can only make matters worse.
Only way to change oil from an auto box is by drain.

 

[Uberwagon]

>> Draining has to be better...

Why?

Show us some **evidence** of premature engine failure because of using a vacuum pump to remove the oil.

I could squeeze a bottle of ketchup into my engine and it wouldn't cause premature engine failure, but it doesn't mean it's the correct thing to do.

When you drain it using gravity and the sump plug at the lowest point, you get more particles of dirt, general engine crap out.

Sucking the oil out is a comprimise and from the units i've heard about (I've never used the small electrical ones myself, only larger more industrial based pumps) it is far slower aswell.

So the pros and cons......

You stay cleaner with the suction method
You can drain directly into a container to get rid of the oil correctly
No need for ramps
No need for sump plug washer

More expense on buying the pump
Less oil is changed
The particles of dirt, metals (We are talking very small amounts here, i'm not saying you have a bag of sand in the sump) are not sucked up as much due to that evil bitch gravity.

If i'm doing an oil change, I want to change as much of the oil as possible, not do a partial oil change and lose some of the benefits of it, sucking it out is a comprimise due to time or packaging constraints.

Dave!

 

[WLeg]

So cost v Quality ???? - and where would a large commercial dealership go......

Sump plug every time.

If MB or any other maufacture wanted you to suck, why would they design in the sump plug in the first place ?

 

[nickcc101]

Definately NOT recommended for changing your ATF on an auto box.

It will suck any shrapnel up from the filter outer, displacing it in the last places you want it to deposit. defeats the purpose and can only make matters worse.
Only way to change oil from an auto box is by drain.

Handy for removing excess oil if you overfill following atf oil and filter change (I know i am that dic?head who put too much oil in).