PeachParts Mercedes-Benz Forum - View Single Post

Benzadmiral · #3 02-03-2005, 09:54 AM

Hi, Mark,

I had a 420SEL for over five years, and changed the oil as you do every 3K (when I drove more, in Denver) or 3 months (I drive less back here in NO). It's very easy. I too used Delo 15W-40 in the big grey beast, and when I had to have the oil pan replaced due to pothole damage, my regular mechanic said the inside of the engine was as clean as the proverbial whistle. I also noticed better hot oil pressure with the 15W-40, even though it's technically thinner than the 20W-50 I'd used earlier.

You'll need a 13mm socket to remove both the bolt for the oil filter canister and the drain plug down below, if you do the traditional draining method. Of course have paper towels on hand, and those rubber surgical gloves are neat -- they'll keep your hands clean and let you handle warm metal.

1. You'll need a big pan that holds 9 quarts or more, because your engine holds 8.5; those little 5-quart pans won't cut it.

2. The filter canister is located on the passenger side of the engine (if you're in America. If you're in a country where you drive on the left, I suppose it's on the same side as the steering wheel). The nice thing is that it's only about halfway down the side, so you can reach it from above; none of that using a filter wrench on a canister sticking out of the engine while you lie on your back and get a faceful of oil. Undo the bolt, lift off the canister lid, remove the old filter, put in the new (I used Mann or Knecht filters). It can only go in one way.

3. When the oil's finished dripping, put the plug back with the new copper washer that comes with the oil filter. Snug it down. I don't know the torque; I always just got it tight and checked for leaks.

4. Up top again, replace the large rubber gasket around the edge of the filter canister lid with the new one from the oil filter package. Lid back in place. I think there's a copper washer for the bolt, too. Snug it down with the socket.

5. Put in 7-8 quarts of oil.

6. (Optional; recommended to me by my regular mechanic in Denver) Unplug the coil wire (you'll find it at the right front of the engine compartment, your right as you face your car). Again, make sure the oil filter canister is tight, and that you put in the oil! Then crank the engine, watching your oil pressure gauge, until the needle begins to come up to 1 or so. Hop out, reconnect coil plug, hop back in and fire up the engine.

7. Let it run for a minute, watching the oil pressure of course. Shut it down, check for leaks. Give it a couple of minutes to let the new oil drain back into the sump a little, then check the dipstick. Top off the oil as needed until it reaches midway between the Add and Fill marks.

8. Take nasty old oil to recycler.

9. (Most important point) Revel in the knowledge you've done it yourself, it was done right, and you saved a ton over going to what people here call Jiffy Screw.

Now if the draining thing is awkward for you, you can use the oil suction device called the Topsider. Do a search here and you'll find lots of pro and con information on it. I bought one and am glad I did.

Good luck!