Is my oil consumption excessive

[pj67coll]

In the 1000 miles since I did my last oil change my oil level has decreased from the top mark on the dipstick to just over the halfway mark on the dipstick. Would this be excessive?
81 240D. 220K miles since a rebuild.
- Peter.

[RobTheMod]

There are many who would say so... I'm not one of them. You've seen my 300SD... she leaks/burns a quart per 1000, unfortunately, but that figure hasn't changed since I bought the car 2 yrs ago and 30,000 miles.

Even having worked on VW diesels since 1996 I've never seen people so obsessed with blow-by as the members of this forum. You will no doubt get a bunch of doom/gloom responses to your query, and I'm not even trying to start an e-fight by talking about my (admittedly notable) oil consumption, but really, truly...

I WOULDN'T WORRY about it.

[Kuhlrover]

I wouldn't worry about. The cost for the added motor oil is cheeper the solving whatever the internal problem is. If it's leaking gobs of oil, that might be worth checking out. The good thing is you obviously check your oil and know you have to check it often therefore you are less likely to run it dry. It's is amazing how many folks I talk to at work that never check there oil.

TimK

Don't worry about it. I leak and/or burn about 2.5qts every 3000miles.

I've just made it a habit to check my oil level and add 1/4-1/2qt of oil every time I get fuel.

BTW, you should keep the oil level about 1/2 way between the marks. Some suggest that oil consumption will be less if you keep the oil at that level.

[Cervan]

mercedes says that you should rebuild the engine when it starts to burn a quart of oil every 1k miles... looks like your at that milestone. to tell you the truth i had a 1981 240d it started off about a year ago burning maybie a quart every 500 miles. then it slowly started to get worse quart every 400 then 300 then it became a quart every 10 miles no joking i didnt leave out a 0 every 10 MILES friggen insane. i would drive to school and have to add more oil. but onec you get an engine that doesnt burn oil you will realize that its really worth the money to get the engine fixed.

[Lycoming-8]

On the dipstick in our 300D, that level of consumption would translate to 1qt per 2000 miles or less, and would seem to be a long way from worry time. As others have said, if any of that use is due to leaks, locate the leaks and fix them. Finally, again as someone else has said, actual non-leak consumption seems to be less if you try to maintain the level at the mid point between the notches rather than at the top one!

At this point you need to check the level on a regular basis such as every Friday or when you fill the tank, just to be sure nothing has changed and to avoid that when the oil pressure goes to zero!

[pj67coll]

No leaks I'm afraid. Given the amount of smoking it suffers from if it's dissappearing anywhere it's out the exhaust. I shall try to see how far I can go with the level hovering around the 50% mark. If it turns out that the engine is on it's last legs. Oh well. I'll just try to look after it and see how far I can go with it. Would be nice to get that 750K kilometer badge though.

- Peter.

[t walgamuth]

that amount of consumption is not that bad.

remember also that the marks for high and low represent two quarts on the 240 engine.

i never found increased consumption by keeping the oil full. just keep an eye on it and be careful about loaning the car to anybody else.

i once loaned my suburban to one of my sisters for a few days and when i gotit back it was three quarts low iirc. since the suburban only held five, iirc, i was pretty steamed.

good luck.

tom w

[captainmonk]

put a quart of lucas oil treatment in and you wont add any between oil changes and you will forget you were worried about the engine

[t walgamuth]

couldn't hurt.

tom w

[barry123400]

You live in a hot enviroment. Using straight 40 grade will reduce consumption quite a bit. Quart a thousand is not terribly bad but you can do better if you wish.
The better cylinder sealing with the heavier viscosity gives you a small compression boost as well sometimes. It should on average cut your consumption in about half in my experience. Of course results will vary but there will be quite an upside.
Also the heavier oil cushions worn parts better. Try to quote the difference on a future thread as I suspect a few members do not believe the difference that is possible.
I rate any 616/617 engine at a quart every 1500 miles fairly decent still. Also check your air cleaner for oil saturation as that will not consume oil but semi smother the engine causing more smoke and poor milage. This is not an oil thread exactly thank god.
Some brands of oil seem to burn and drop faster in these engines as well. There is a lot to be said for filling only to the half dipstick mark on too many occcassions to ignore as already mentioned.

[pj67coll]

Ah. But maybe we can turn it into an oil thread! Wouldnt that be fun

Seriously though. I shall be watching it like a hawk. One question I do have is if there is any connection between the vacum pump and oil consumption? Seems I read that somewhere but dont see how it can be.

- Peter.

[lee polowczuk]

well, my 260e burns a quart per 350... yes i am concerned... yes i will do valve stem seals at some point.

however, i think my upper end probably could use a rebuild even thought the engine is smooth as silk.

i know i don't have a diesel...but i just wanted to put this in perspective for you.

i drive this car 100 miles a week.

[barry123400]

Really poor valve stem seals on a mercedes gas engine will allow heavy consumption of oil. Just accelerate and back off with someone behind you. If the cloud increases when you back off the gas suddenly change the valve seals and check your guides.
You probably are already aware of this test on gas cars.

[vstech]

the seals on the vacuum pump can fail, causing the pump to force pressureized oil into the air cleaner through the vent tube.
John