MBWorld.org Forums - DIY - 250BT Oil Change and DEF Refill

I completed the first oil change and DEF refill today on my 2013 250BT. They were relatively simple procedures but they took a little longer due to some blunders on my part.

First off, tools required:

8 mm socket- to remove mid plastic guard
13 mm socket - to remove oil drain plug
22 mm socket - fits over oil filter wrench
Oil filter wrench - MB Part #103-589-02-0900

Parts:

Oil Filter - MB Part # 651-180-01-09
Mobile 1ESP 5W30 (7 litres) - MB Part # Q-6-02-0649
AdBlue/DEF1.89 litre - MB Part # 000-583-0107 (one-time purchase, you will reuse the empty container to fill the tank)
Bulk DEF(Available at various parts stores)

Miscellaneous:

Rubber Gloves
Paper Towels
Mityvac or drain pan
Safety Glasses

Now on to the procedures:

Oil Change:

1) Start off by ensuring that the oil is warm (I find that the oil extracts/drains easier when warm). Go for a ride and ensure it has been brought up to operating temperature. Let the vehicle sit for 15-20 min to ensure you are not dealing with scalding oil.

2) I started off attempting to vacuum (Mityvac) the oil out from the top, but only managed to extract about 5 litres. I highly recommend that you forego attempting to extract the oil from the top IF you are concerned about ensuring all the oil is drained. Try as I might, I couldn't get more than about 5 litres out of the top!

3) Plan B - drain oil from the bottom

4) I found that I didn't need ramps to get under the vehicle but to get some extra clearance, I positioned the front wheels on 2 inch concrete slabs. Just drive slowly up on the slabs then chock the rear wheels for safety.

5) Remove the mid plastic guard with an 8 mm socket - there are 8 fasteners (if I recall correctly) that need to be removed - 4 are located up towards the front, 2 in a recessed well and two towards the back (I made a mistake by removing the rear guard instead of the middle plastic guard and after some probing around I couldn't locate a drain plug so I knew I had removed the wrong panel)

6) Locate and loosen the oil drain plug with a 13 mm socket but do not remove until you have the oil catch pan positioned well over from the centre point. I had some difficulty locating the drain plug as the drain pan on the GLK doesn't resemble your conventional pan. There are many nuts below that may resemble a drain plug so be very careful. Loosen the oil filler cap in the engine compartment to help with flow.

7) While oil is draining, remove the engine cover to gain access to the oil filter cover. Unscrew the plastic fastener at front of cover using a large slotted driver.Slide engine cover towards the front and it should release from the two rear tabs.

8) Position the oil filter wrench over the oil filter cover and ensure it is properly seated. A 22 mm socket with an extension fits on the filter wrench, turn counter-clockwise to remove. The cover and filter should come off together once removed.

9) The filter is friction-fit on the oil cover assembly. Grab the filter and give it a good tug to remove. Lubricate and replace all the included O-rings and reinstall the filter cover.

10) Reinsert the drain plug - do not over-tighten (I reused the copper crush washer since I neglected to pick one up when I purchased the parts)

11) Fill engine with 6.5 litres of Mobile 1 ESP oil.

12) Start engine and check for leaks - if no leaks, replace engine cover and plastic under-body panel in reverse order.

13) Reset the service indicator

DEF Refill:

I followed the user guide provided by another forum member.

If you avoid some of the errors I made by removing the rear under body cover, I reckon you can get the complete job done in about 30 minutes.

Hope this helps.