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Thursday, November 12, 2015

2009 Mercedes Benz GL550 Oil Change X164

OK...  So this blog is supposed to be about 1:64th TINY cars, not 1:1 scale huge, hulking beasts of cars...
But I just did my first (and very overdue) oil change on my '09 Mercedes Benz GL550, and I was appalled to find that there were NO internet resources showing how to do an oil change on this car...  (Apparently high-end MB SUVs don't have the same DIY communities as those that support my Mazda Miata...). 

Ordinarily I wouldn't expect to need help with an oil change.  But after sliding around underneath the car and finding nothing that looked remotely like a drain plug, I decided to check the internet...   ...only to find that there was appallingly little information on the internet. So this blog entry is my attempt to remedy that situation! 

Apparently, the "correct" (and easy) way to change the oil is to pump it back out of the dipstick spout.  But I don't have a large enough fluid transfer pump, and didn't want to get my little one all oily, and I was bound and determined to change the oil the old fashioned way.

So here's the deal:

The drain plug is hidden beneath the plastic under-engine shroud at the very front of the car.  The good news is that you don't actually have to get your body under the car (you can reach in from the front).  (You can see jack stands in the photo - but these were already in place before I realized where the drain plug was). 

The bad news is that there are about roughly 8 hex head (10 mm) screws that you have to remove in order to get the shroud off - so you'll spend 10 minutes just cranking away with your rachet wrench - your arms getting more and more tired in the process.  This part alone makes me consider buying a fluid transfer pump for next time.  When you get the final bolt off, the shroud slides backwards and then drops away.  At that point the drain plug becomes clearly visible on the passenger side of the car, facing the front of the car.  The drain plug comes off with a 13 mm socket.  Now you are done with the hardest part. 

Once the oil is out, the filter change is really easy.  I bought my filter from the dealer for $20-$25 - its a basic paper filter as is common in German cars.  You need to remove the front shroud from the top of the engine - this time thankfully there are no screws - you just pull it up and it comes off. 

The oil filter cover is immediately visible - a black plastic cover - in the photo on the right you can see the shadow of the dipstick falling on the cover. 

Next (small) problem is that the filter is recessed - so it was a little hard to get my oil filter wrench around the filter cover.  But eventually I got it off, and then the filter assembly just lifted out. 

The old filter pulls right off of the assembly and the new filter slides right on.  Push the new filter into the assembly as far as it will go (there were directions on my filter that showed that I needed to push it further than I originally expected.  Then replace the whole assembly and put the filter cover back on. 

I put 9 quarts of oil into my car and filled it up to the top level.  Obvious note - check the oil level when the car is NOT still jacked up - otherwise the oil will be more on one side of the car and the dipstick will not show the level correctly.  Next time I'll plan to just put 8.5 quarts in and then very slowly add the last 1/2 quart.  (Note that I saw some internet references to a 2nd drain plug for another oil reserve - but it seems like I got out 95+% of the old oil so I'm not worrying about it).  

The last step is to reset the maintenance indicator light - as follows:
1.  Make sure doors are closed.
2.  Push engine start button without pressing brake pedal - turning on just the accessories
3.  scroll through the menus using the steering wheel buttons until the odometer is shown
4.  Press the "R" reset button (above the speedometer) 3 times very fast - you'll here a beep
5.  Press the down button on the left side steering wheel keypad
6.  Press the - button on the right side steering wheel keypad 3 times until you see a confirmation question
7.  Press the + button (right side steering wheel) to confirm the service reset. 

Hope this helps anyone else who loves their massive GL550, but doesn't want to pay the dealer $200 for an oil change! 


  1. Awesome post, thank you very much for this information, like you mentioned there is nothing online about changing oil on these 2009 GL550's Benz. My wife drives it and so I wanted to do the oil service myself and save a few bucks. Im a certified mechanic by trade but do not have the workshop at the moment. Thanks again.

    Abraham Yates @ Apache Oil Company

  2. Thanks for your note - I'm so glad that the info was helpful for you!