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Draining Engine Oil vs Extracting Engine Oil

Published on August 15, 2014 under Humble Mechanic
Plastic oil pan MK7 GTI

Plastic Oil Pan?

A few weeks ago I posted a picture of the oil extractor that I bought. I mainly bought it because someone at Volkswagen thought it would be a good idea to use a PLASTIC oil pan on the new MK7 GTI. It’s too early to know if a plastic oil pan is a good idea or not, but let’s shelf that for now.

When I posted the picture, it brought up a good point. Is extracting oil better, worse, or the same as draining it from the drain plug.

Before we talk about the Pros and Cons of these methods. Let’s be sure to define each.

  • Draining Engine Oil
    This is the process where a plug is removed that the oil drains out the bottom.
  • Extracting Engine Oil
    This is where a device is used to suck the oil out. For this discussion, let’s assume we are pulling oil out through the dip stick funnel.

When most folks think of an oil change, they think of draining the oil. Up until a few months ago, that is how I did every service. Let’s talk about the pros and cons of DRAINING oil first

Pros

  • It is fast.
    We are letting gravity do the work for us. On a hot engine you will get most of the engine oil out in about 5 minutes.
  • You MAY get more oil out.
    I say you MAY because that is not a guarantee you will get more oil out
  • You can do other things while the oil drains.
    I usually pull wheel caps off while I drain the engine oil
  • It is a more traditional way to change oil

Cons

  • It can be messy
    You basically need to be sure you hit the target of the drain pan
  • You have to raise the car up.
    You need to have the car high enough to access the drain plug
  • Risk oil pan damage
    May oil pans are made of soft metal, or plastic, each time a drain plug is removed, the potential for damage is there.

    Passat TDI Oil Change

    Extracting engine oil

Let’s look a little deeper into the Pros and Cons of extracting engine oil

Pros

  • Clean
    All of the oil is pulled in to a container. Mine has a spout to make pouring easier
  • No need to raise the car
    This is great when putting the car in the air is not easy.
  • No worry about drain plug damage
    A you can see I am concerned about the long term on these plastic pans.

Cons

  • Noisy
    Mine is fairly loud
  • Need air supply
    With most of these extractors, you need a good supply of compressed air, or you have to manually pump the oil
  • You may not get all the oil out
    I have found that mine does not get all the oil out of some engines.
  • It may take more time
    On a cold engine, my extractor takes forever to pull oil  out.

There are a few other points that I want to bring up about using an extractor. They may or may not be cons. It is more like just thoughts. Just because you don’t need to put the car in the air to drain the oil, doesn’t mean you don’t put the car in the air. You may still need to access the filter from the bottom. It is also important to put the car up in the air to do an inspection.

There is also the idea that debris in the engine oil will settle to the bottom. When a drain plug is removed, that will be the first to come out. This sounds like a good theory. But the oil filter will hold most of the debris. The oil is changed HOT. This means the debris doesn’t really have time to settle. Plus no matter what you do , there is still oil left in the engine. Heck there is still oil left in the pan.

Mityvac 7300

This is the extractor that I use

Conclusion, which is better?
Well, like most good questions, the answer is “it depends”. For me, extracting the oil on a TDI that comes in to wait is perfect. The filter is on the top, the extractor gets all the way down to the bottom, and the oil is hot.

I can tell you that on a 2.0 FSI, there is is no point to use an extractor. I still have to put the car in the air to access the oil filter. It would be a waste of time to extract the oil, then lift the car to replace the filter.

Your thoughts
What do you think? Is draining better? Do you get more oil out? Does a 1/2 of a cup left in the engine really matter? Post your thoughts in the comments below.

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27 Comments

  1. Pat ~ The Muscle Car Guy

    I can see how a car that you can reach the filter from the top, it would be nice. Plus I have usually had to change oil outside, so a nice breeze can make hitting the pan even more of a challenge than that suspension/frame piece you thought it would miss.

    With the plastic pan, is there a metal insert that the plug threads into? If not, who thought that was a good idea?

  2. David Summers

    I’ve not seen one of these extractors in action. How long does it take and why not use one with a longer hose to extract the oil while the car is being lifted for the courtesy inspection and access to some filters? And what makes it loud? Using the venturi effect?

    1. Charles

      @David,
      The extended hose is a good idea. I think you may loose some suction with a hose that is too long. I believe that it does use venturi vacuum. That is what makes it loud. And to be fair, it is not CRAZY loud. Quieter than most air impact guns. For me it is just a constant “SSSSHHHHHHHHH” while working on the car.

      If the oil is hot, it does the job pretty quick 10 minutes maybe. I use that time to get my parts for the service I am doing.

  3. Scott

    On my C240 Mercedes when doing an oil change at home means car on ramps and drain plug at the lower portion of drain pan.
    Using the extractor was an easy way to get oil into a container for disposal at recycler. The Topsider extractor is a compact low metal container that is easy to place in trunk and haul.
    Even after extracting – and this is a preferred (I believe ) Mercedes method for oil changes – I always got an ounce or two of oil when pulling the oil-pan drain plug. This car was some nearly eight-quarts of oil.

      1. Bryan K.

        It still has a dipstick tube. The dipstick is just optional. You can purchase the dipstick from the dealer (stupid I know).

        I’ve been extracting the oil using mityvac in my shop for years. I do a lot of W203 Mercs with the M112 motor.

  4. Marty

    I find oil changes to be a perfect time to look at the underside of the car. There is a lot to be said for knowing that is grease dripping out of the CV boot joints or there is a small stream of dried coolant from the decaying plastic coolant flange that a VAG bean counter thought was a good idea, too.

  5. Myron Ursua

    Sounds like Volkswagen is figuring out ways to shave weight. My overall opinion if you’re charging the customer for an oil change & inspection still need to hoist up the vehicle. I rather drain the oil using gravity & inspect the vehicle a tire could be punctured never know. using plastic oil pans BAD IDEA!!! One puncture while driving engine is history. Unless the engine shuts off due to low oil pressure. I can imagine the cost for a new oil pan you can weld up a steel one. Especially the ride height of the vehicle jumping the curb Oh boy! At least put a skid plate scrapes happens. Customers won’t be happy to pay for a new plastic oil pan

      1. Surjit

        We have been using plastic oil pans (material called smc) for years on 12 and 14 litre engines for years without issue. Diesel engines producing 1800 ft pounds torque produce a lot of vibration and thermal stresses. The pans and plastic valve covers can last the life of the vehicle which can easily exceed 1 million miles. As for hitting the pan on something in the road that could happen on aluminum or steel pans as well. The drain plug bosses are really hard to damage unless you go full primate and over torque them which would be human error. Modern materials are lighter and very strong compared to the stuff we are used to!

  6. Brad

    I work parts at a small VW dealer, and we have three techs. Only one of the three use the oil extractor (the others use it, but very rarely), and he hooks it up and turns around to play on his phone. He is the only tech that rarely brings an estimate into the parts department, and has many comebacks. I think the pros and cons of an oil extractor all depends on the person using it. While tech A might use it to knock out a walk in oil change, while doing a DSG service. Tech B uses it to be lazy, and never even lifts the car.

  7. Dan

    Don’t know if VW’s come equipped from the factory, but if there is a magnetic drain-plug [my 97 GMC had one] you cannot clean it or see if there’s coming trouble [larger bits on the magnet].

  8. Dwight

    Between me and my kids we have 3 Hondas, 2 Acuras, and an E250BTC diesel MBZ. I have an extractor. It works great on the V6 Hondas and Acuras because the filter is accessible right behind the right front wheel. Cock the wheel full right and the filter is easily spun off and on again without lifting the car. The extractor pulls out the expected number of quarts/liters. The Accord is a 4 cylinder and the filter and drain plug are not easily accessible without lifting the car so I don’t bother using the extractor.
    I got the extractor after performing the B service on the MBZ and realized there is a large under body panel with 6-8 screws that must be removed to access the drain plug. A real pain, particularly when the filter is top mounted and easily accessible. On the next change however using the extractor I was only able to remove 3 liters with the extractor. I don’t know why. Possibly the tubing hung up on something before reaching the bottom of the pan, or the fact I didn’t loosen the filter before extracting the fluid could have been the problem. I simply refilled it with just 3 liters, when it should have taken 6. If anyone out there has encountered a similar problem I would like to hear from you. Thanks.

    1. pan

      Dwigt, its normal for some mercedes. It has no related that you didn’t remove filter before or not but MB crank in some model is complicate, the tube can’t go far to extract all of the oil. Because of this, you need to do old style oil extract by remove the nut under your engine. Mine car C180 M274 engine got the same thing as your.

    2. Steve Davis

      Yes I tried the Topsider Oil Extractor purchase on Amazon at $50. No matter how many times I tried, I could only remove 2 quarts. It would suck out 2 qts. I would drain into a container. Pump up the unit again, but could get NO MORE oil. Only 2 quarts out of 4.2 quarts with a normal drain and fill. My car is a 2009 Hyundai Elantra 2009 SE.

  9. Des

    Extractors are great if you are driving the car a ton, or track it once in a while, and only change the filter every other time. I do my oil every two months, which seems excessive, but it’s just a paranoia I have.

  10. john

    i put a lot of klm on the car in a year. i like the elc pump because i can do a quick oil change in the dead of winter 10 min tops. i use a high klm oil filter,and change that out every 10,000 klm.
    coming from the trade, i find this cost saving and easy.

  11. Kent

    Audi A4 B7 2.0T Quattro. The extractor method works for me. I hate crawling under the car and removing the belly pan (pain) and getting oil dripped on me (also a pain) so I rigged up an extractor using a small electric vacuum pump and a 2 gallon drop-out can. The engine has a fairly straight dipstick tube so it easy to snake a 1/4 inch plastic tube down to the floor of the oil pan. Just to verify, I removed the oil pan plug after extraction and virtually no oil came out, oh maybe a drop or two, so I feel confident I’m getting all the oil out of the pan. As for the filter, this engine uses a cartridge filter arrangement. I use a Baum Tools BT40057 drain tool and hook up the extractor to that to draw oil from the filter housing. Takes just a minute or two. I then unscrew the filter housing from above. Tip: surround the filter housing with a medium size plastic bag then unscrew the filter housing and drop the housing and cartridge into the bag. Lift the bag up and out of the engine bay. No mess. My entire oil change is done from above. No jacks, jack-stands or ramps. Kent.

  12. Ash

    I say the more one can do for yourself on your car, the more bucks in your pocket. There are very nifty pumps out there to extract the oil also one can make your own using stuff lying around in your home etc.
    just check Youtube out for ideas.

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