Burning oil loosing a quart a month??? HELP... - PeachParts Mercedes-Benz Forum

disbo100 · #1 10-07-2010, 08:19 AM

Hey Guys,

Well my oil consumption on my 98 Diesel is getting worse.. I'm at 254K and my "add oil" light comes on about once a month. I check the dip stick and it’s a 1/4 inch under the full mark. So I add a 1/2 to 1 quart.. About a month later its comes on again.

I'm not leaking more than a drop or two.

My guess (and yall correct me if my guess is wrong) is that oil is sneaking past the rings and being burned. I can see this when I stomp on it and there is a much BIGGER and BLACKER cloud of smoke out the tail pipe. The folks behind me REALLY don’t like it.. They slow down really fast.. HAHA
Since the market is really down for cars I don’t see it being economical to pay some one to crack the head and replace the rings. I checked eBay and ones with over 250K on this with similar issues were selling 4-6K but closer to 4-5. To do the work it would be around 4K..

* I've run Marvels through it to bust it up... Used a pre oil change product to loosen everything up, then changed the oil.

That bought me a few extra weeks.. 6-7 before the light came back on instead of 3-5 weeks.

Can I do anything else other than crack open the head and get to the rings? Or do I just keep putting oil in it and changing it... And hoping for the best??..... HAHA

buffa98 · #2 10-07-2010, 08:48 AM

How many miles during that month? I have to add a Quart at 2k then it is a Q low at 3k when I change it.

Daman858 · #3 10-07-2010, 09:22 AM

Did you run Marvel through the fuel or did you remove the injectors and squirt some in and let it set overnight? The latter worked well for me...compression up and oil use down.

Anyway, your oil use in a car with those miles does not seem excessive.

DieselPaul · #4 10-07-2010, 09:44 AM

Your location and car aren't listed, I'll assume you're in the US, and you have an E300 Turbo. Have you checked your turbo for play? Your turbo could be using oil.

vstech · #5 10-07-2010, 10:07 AM

can the valve seals be changed on that motor? 250K certainly could have enough wear to warrant investigation of both the seals, and the turbo seals.
I agree that the Marvel Mystery oil needs to be soaked into the pistons through the injector holes. I'd also put a quart in the motor oil and drive about a week or so prior to an oil change. it could assist the piston squirters, and the valve seals too.
it could also cause varnish on the front and rear mains to melt, and allow the seals to leak, so make that a last resort attempt.

Jeremy5848 · #6 10-07-2010, 10:16 AM

If the "add oil" warning comes on when the oil on the dipstick is almost full, the problem could be the float switch in the sump could be faulty. It's a common failure item in high-mileage 60x engines. The warning should not appear until the oil is at the "low" mark, 2 quarts down. About $40 for a new switch and you can install it yourself next time you change oil.

If the dipstick is correct, you are over-filling the crankcase. The excess oil is likely being burned off, that's why the level keeps falling.

Jeremy

vstech · #7 10-07-2010, 10:23 AM

I just noticed the "I'm not leaking more than a drop or 2" part of your post...
do you mean you see a drop in the driveway? or your motor and undercarriage are completely spotless except for SLIGHT residue on gasket surfaces and such?
a drop in the driveway is equal to QUARTS being dumped on the road at highway speeds...

scottmcphee · #8 10-07-2010, 10:43 AM

If your oil pan is wet with oil and you're slowly giving yourself an undercoating of rust protection, check the front crank seal.

Diesel911 · #9 10-07-2010, 11:48 AM

There was a couple of threads where the members said that tiny O-ring in their Fuel SupplyLift Pump was worn and that Oil was being sucked from the Fuel Injection Pump Cam area into the Fuel Supply Pump and mixed with the Fuel.

You might get a Glass Jar and take a Fuel sample and hold it up to the light. One of the members said that it gave the Fuel a Blackish tinge. The reason is becaue the Oil+Fuel mix mostly gets returned to the Fuel Tank.

In the below thread there is a pic of the Fuel Supply/Lift Pump in post #3. The Arrow at the far right points to the tiny O-ring.

http://www.peachparts.com/shopforum/showthread.php?t=285915

babymog · #10 10-07-2010, 02:38 PM

As mentioned above, you do not need to add oil until it is below the ADD mark, never above the FULL mark. My 603s (same bottom end) all run happily at the full mark, at 250,000 miles you should be burning no more than a quart/3000miles but overfilling can be a problem.

The oil light is off (as mentioned above again), or the dipstick is. No oil light until beneath the add mark.

Are you burning WVO? That has been indicated by some to cause ring sticking and increased oil use / low compression.

disbo100 · #11 10-07-2010, 03:59 PM

Hi Folks,
Tons of great comments thanks.. Ill address each one

How many miles during that month?
**1500-1800 before the light and dipstick are lower than FULL.

Did you run Marvel through the fuel or did you remove the injectors and squirt some in and let it set overnight? The latter worked well for me...compression up and oil use down.
**Yes, I ran 1/2 bottle of Marvels through the gas tank. Not much gain in oil loss.

Have you checked your turbo for play? Your turbo could be using oil.

**I have no idea how to "check the turbo for play"... Do tell....

If the "add oil" warning comes on when the oil on the dipstick is almost full, the problem could be the float switch in the sump could be faulty. It's a common failure item in high-mileage 60x engines. The warning should not appear until the oil is at the "low" mark, 2 quarts down. About $40 for a new switch and you can install it yourself next time you change oil.
If the dipstick is correct, you are over-filling the crankcase. The excess oil is likely being burned off, that's why the level keeps falling.

**On my lunch hour I went out and took a look. I added a quart yesterday and its sitting right at the full mark.
Before I filled it up the "add oil" light came on so when I got home I checked it. I'm using my calibrated eyeball so bear with me. The distance from the Full to add line is apprx an inch or so.
Before I added oil the level was about 1/8 the difference between the add and full.
To ensure I don’t overfill it should I wait until the level is HALFWAY between the hash marks? And kind of ignore the light?

** I'm guessing the one fellow hit it on the head when he said the float was bad an I'm overfilling it.

I also like the idea of pulling the injectors letting the soak and putting some marvels in the cylinders to also let them soak.

Thanks Chris

Ill do a few of these and keep yall posted..

02isb · #12 10-07-2010, 04:18 PM

pull the air intake from turbo and crankcase vent and see if its oily. if its over filled it will show up there.

my car has right at 300k and no oil usage and the dipstick has shown level to be about 1/8" up on the red. ( a little overfilled) and hasnt moved in 2500 miles.

good luck

disbo100 · #13 10-07-2010, 04:24 PM

LUCKY.... I have a case of oil in the garage.. Ill dump one in every 3-5 weeks..

DieselPaul · #14 10-07-2010, 04:40 PM

Pull the boot off of the turbo see is its a nasty grimey mess. You try to move the impeller in and out with your fingers to check for bearing play. I'd look into the other ideas before you play with the turbo.

disbo100 · #15 10-07-2010, 04:49 PM

Yes, I agree Ill hold off messing with the turbo since I've never played with it much.

To answer one of the questions there is some slight oil in the big rubber hose that goes to the turbo but not a ton.
More wet than anything else.