Well... I did it! Gonna see what happens.
 

I switched to Mobil 1- 0w/40w FULLY SYNTHETIC! I have been using Shell Rotella- 15w/40w but the 240D goes through Rotella faster than you can say "scat". I use Rotella T in my 81 VW Rabbit Diesel with fantastic results!

I am almost positive that my oil consumption will INCREASE! I figure I am on my way to a rebuild anyway so I decided to go ahead and clean out the internals;) .

I was just wondering. I have seen several mentions in some previous posts that Texaco Ursa didn't seem to burn as quickly in some engines as other oils (synthetic or dino) did. The PO of my 240D used Texaco Ursa in the engine before I purchased the car (I assume he did because there was an empty Ursa gallon container in the trunk). He told me that he changed the oil religiously.

After driving the car several days (@ 400 miles) I checked the oil and it was at the low mark on the dipstick so I topped it off with Shell Rotella T 15w/40w and never even considered Ursa. Honestly, I didn't pay any attention to the gallon container in the trunk until after my first oil change with the car. This car burns at least 3/4 of a quart per tank of diesel.

In light of the fact that some have noticed significantly less oil consumption using Ursa, would it be wise to revert back to Ursa since the car has been on Ursa for several years?

I am so sorry to bring up anything related to oil:rolleyes:

Thanks,
Oilslick- oops! I did it again!:eek:

"so I topped it off " exactly what do you mean by that ?

"Topped it off" was not the best way to put it! My mistake:rolleyes:

I added oil until it read somewhere between the full and add marks. I will have to say that I leaned more toward full but not completely. I have never been one to fill any car engine up to the full mark. I kinda figure that low notch is there for a reason. Anything above that(not exceeding the full mark) is ok if you ask me, but nobody did.;)

oilslick

I use a LOT more oil if I keep it at the full mark... so I am now keeping it half way or less....and I am not the only one to report this quirk....

Ahem. As gsxr pointed out to me, they aren't full and add marks, they're max and min marks :)

Were you the least bit alarmed that 0W-40 seems less viscous than water? I thought I was pouring in coffee the first time I tried 0W-40. Too freaky so I switched to 15W-50.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

I'd lean toward 15W50 in a 240D -- watch your oil pressure at idle hot. I'm not convinced that 0-40 oil is thick enough for a diesel.

If your oil pressure is very low at hot idle, change to 15-W50.

Peter

PSFRED, LEATHERMANG & SIXTO
 

Thanks for the information. I did notice that the oil was very thin looking. I really wish I had put the Ursa in it this time, just to see, ya know.

I have noticed that the oil pressure doesn't jump up there as quickly as with the Rotella. Looks like I will be doing another oil change VERY soon. I am sure glad I went ahead and got an extra filter. Now when I go to get the Ursa the oil change won't "seem" as expensive;) :D

Oilslick

If you were to go to Mercedes and request synthetic oil, this
Mobil 1 0w40 is what they would sell you. I went to a dealer and asked once, that's why I know. I'd hate to see you drain 35 worth of oil out of there, especially when I'm very confident it's fine to use. Whenever you start you car when it's hot the oil is thin just like this stuff when it's cold, so what's the harm if you keep it in there for 3k?
Thanks, Adam Bush

point well taken
 

thanks!

There is surely nothing WRONG with using Mobil 1 0W40 in you engine. It will lubricate wonderfully. It will also be consummed much more quickly than will Mobil 1 15W50.

There is A PROBLEM with using Mobil 1 synthetics in your Mercedes engine if you follow the Mercedes instructions in your owners manual (and you have a car that's more than 5-6 years old). Mobil 1 drains VERY slowly back into the sump - AND that means that if you measure the oil level when the engine has been run recently, some of the oil is still draining from the passages. In fact, it takes nearly 8 hours for all of the oil that can drain to drain! That means that when you measure the level of the oil in the sump - unless the engine has been sitting for 8+ hours you are NOT measuring the oil IN the engine but only the oil that has managed to drain into the sump.

The oil level in the sump is largely unimportant (don't believe me - fill up the sump and disable the oil pump - the engine WILL fail). What is important is the oil circulating in the engine. The use of a dipstick to measure the oil in the sump was sufficient when conventional oil was used. Current MB engines DON'T even have dipsticks anymore! If you use the oil level on the dipstick to estimate the oil level of an engine that's recently been shut down and top up the oil level you will overfill the engine by as much as a quart!

I've tried to interpolate what the oil content actually is using the dipstick level and how long it's been since the the engine was shut down and the results have been VERY erratic. The ONLY scheme that has worked faithfully is to read the oil level first thing in the morning before the car is started first time! That level is accurate. If the oil level is taken to much over the midway point between the the two marks, oil consumption at highway speeds WILL be excessive (or at least has been on every one of the 28 Mercedes engines I've ever owned).

Finally, In TSB # 00/57A (11/95) Mercedes warns against owner frequently topping up the engine oil, points out that the optimal level is about midway and suggest adding oil ONLY when the level reaches the lower mark.

Marshall

Very Much Appreciated!
 

I guess I will be waiting till morning to check my oil.

Thanks for the info Marshall Booth!

I will verify that this is correct. One oil change I put in six quarts, started the engine, shut it down and checked the oil. I added oil to the max line(one quart) and the next morning checked it again; I was a quart over:eek:. Now I just add six quarts and leave it at that.:)

You live and learn. :cool:

M.

I find that if I pour in 7 quarts at oil change, the extra oil is rapidly burned off and it soon stabilizes at the correct level. Of course, I'm not advocating this practice; the extra oil is probably frothing and is not good for the main seals.

I've noticed this too, if I let the oil get just below the min. mark it will stay there for a long time :eek:...

Checked the level yesterday morning and...
 

It was between the max and min marks. I drove her all day and pushed her really hard as well. I checked the level last night, about 15 minutes after shutdown, and the level was at the min mark. I thought that surely more oil would drain into the sump if it were given 8+ hours to do so. This morning I checked the level and guess what?

IT WAS AT THE SAME LEVEL IT WAS AT 15 MINUTES AFTER IT WAS SHUT DOWN LAST NIGHT!

I never win! :(

Oilslick

I keep my oil half between the add and full marks and it stays there.My 300D uses (leaks,burns) a liter between changes and that's with over 400,000 km on the clock.If I keep the oil level at the max mark it leaks out the rear main seal until it reaches the halfway point . I run Castrol 15w-40 BTW.

Pros & Cons...
 

Well, I changed to Mobil 1 and was impressed with it. The car DID NOT smoke after the first day of use. The engine performed more smoothly and she would fire off with much more speed. I would have to say that it was a definite improvement!

But.................................My car consumes oil like there is no tomorrow. I can't afford synthetic under these conditions.

After this engine finally dies (which could be ten years from now) I will rebuild it and start using synthetic, maybe, probably, possibly.

Oilslick

How much oil did your engine use after 10-15 kmi on Mobil 1?

It can take 10-15 kmi before the oil consumption settles back down after it increases following it's introduction. The increase occurs as the Mobil 1 starts to loosen the rings.

The 10-15kmi is the time it takes for the rings to reseat (actuaklly it took one of my cars nearly 50kmi to finally stop improving).

Marshall

Too Much!
 

Two quarts in 500 miles!!! Ouch:eek:

She's got to have a rebuild no doubt. I just can't afford the Mobil 1 that often. It's not uncommon for me to drive 300 to 400 miles PER DAY! Dino oil burned at a rate of 1 quart per 400 to 600 miles depending on how hard I drove her.

I didn't expect Mobil 1 to cure the car of the inevitable "wear out" but just wanted to experiment.

Have a good day!

Oilslick

Oilslick:

chances are it was seriously overheated at one time, and the oil control ring expansion spring got annealed. This lets the oil control ring float instead of scrape the oil down, so it gets left on the cylinder walls and burns.

There are other possibilities for excess consumption, have you checked them (such as worn out valve guides).

I wouldn't run Mobil 1 in there either -- the rings aren't going to free up with it if you are running that much clean dino in it anyway!

Peter

Thanks psfred!
 

What is a sure fire way to check the valve guides? I don't know anything about cylinder heads.

Oilslick

I'd also replace the valve guide seals on the off chance that new ones will reduce the oil usage some, and while you are doing that, you can check the valve guide clearance.

When you get the spring off, push the valve down off the seat a couple mm and then push sideways -- if you can feel movement of the stem in the guide, it's shot.

Peter