andys10

I bought my MB Certified ’06 E320 CDI about a month ago (w/ 13 K miles).
After I drove it home the first day, I checked the oil level (using instrument cluster – no dipstick) and the message was “Reduce oil level”.
I took the car back to the dealer and asked to change oil and filter (since it was not clear when the previous owner changed oil).
I checked the oil level several times after that – reading was always correct.
Yesterday the system started to indicate excessive oil level again (“Reduce oil level”)
Since there is no dipstick, the only place I can inspect oil is the filler cap – oil looks clean (not milky).
I’m dropping car at the dealer on Tuesday, but I worry that it could be more than just a faulty level sensor (head gasket? Coolant level is OK and engine is running at normal temp 85-90C)

What do you guys think? Did anybody have a sensor replaced? What else could it be?

Yacht Master

Sounds like, you have one or more bad injectors, (blown tips caused by water in fuel). How is the exhaust look under hard acceleration?

jimbo1mcm

You could just have about a half quart too much oil in your system. I change my own oil and sometimes I put just a little too much in. It will probably go away after a few thousand miles. Obviously, it could be a bad oil level sensor, but get on a level surface, first thing in the morning before the car is driven, and do the oil level check electronically, as described in your owner's manual. Good luck. I haven't heard about problems, as described in the previous post.

harkgar

You can afford a $120 MB dipstick if you can afford a Mercedes. Buy one.

This "tool" is an over-sized clibrated dipstick with a red finger ring tip and is for all intends and purpose a dipstick which is 6 inches too long for your engine. They want to make life difficult for 2005 - 2006 owners so they took out the dipstick. For some reasons the dipsticks are back in the 2007 and newer GL320 CDi again (due to customer complaints?)

You can check the oil level with this dipstick and take the guessing out of oil level in your engine. MB does not want you to touch the engine and take everything back to the dealerships. The color of the oil cannot be accurately checked at the filler hole. Look at the oil on the dipstick (the "tool") as it can sit right in the pool of oil.

If you really want you can ask a machine shop to shorten the dipstick and keep it there all the time.

Another practice of MB recently is to use a pump to suck out the oil when you go in for an oil change. I will stick to the drain and fill instead of the "sucking" as there will always be oil left in the engine with the latter. This is an attempt to save on labor.

andys10

Thank you for the reply.
I don’t quite get the injector theory. It is a Diesel, so it should have a water separator in the fuel filter. So you think the injector is just leaking fuel passed the piston rings and dilutes the oil?
I don’t have this car long enough to comment on fuel economy but it seems to be OK. The exhaust has a dark puff at first hard acceleration but all next accels are clean.

andys10

I checked oil level several times during first week after the oil change and the level was OK. I'm always checking oil level at the same spot on my driveway which is leveled.

andys10

Please, tell me more about this dipstick. Where do you buy it, at the dealers?
I assume my engine has a plugged hole in the crankcase or oil pan. Correct?
If the dipstick blade is shortened, could it stay on the engine? Is there a mounting clip for this dipstick to attach to the engine?
Thanks.

Yacht Master

Andy,
It is not a theory, water could have been introduced in many ways. The only way to remove all water from diesel fuel is a centrifuge, far less effective way is your water separator, and that can be undermined many ways too. Even water suspended in the fuel will damage the tip and cause poor spray pattern and a leak down after shut down. If a diesel engine "makes oil" only one possibility, it is the fuel, and the injector on your car is the only point of entry. My advise buy and install MB dip stick (not the universal tool) make sure it is calibrated correctly (synchronize with electronic sensor). Change oil prove dip stick calibration, start oil log. If you continue to "make oil" all the injectors must be tested.

harkgar

First of all remove the plastic cover on the driver's side. This will expose the red cap which is where the dipstick goes into. I keep my cover off for easy access and there is no increase in noise levels. I am attaching a photo posted by someone else on this board.

Yes. You buy the "tool" from MB. You probably have to order. This tool measures both the engine oil and transmission oil levels as I understand it. My stick is in my non-MB mechanic's shop so I cannot tell you the part number. It was purchased a number of years ago between me and a friend with a 2004 E55, also a car without a dipstick. I use the tool to measure the transmission oil level in my 1999 E55, a car with an engine dipstick but not a transmission dipstick.

I think MB is crazy not putting a dipstick in every hole.

harkgar

Please refer to the attached photo. The red tab is the cap for the dipstick hole. Pull it off and insert the tool to measure oil levels. You will need sockets and a magnet to remove the nuts as they are well receeded into the plastic cover.

I am not serious about shortening the dipstick as it is calibrated and can be used to measure the transmission fluid level too. If you must shorten it do so from the red finger ring side.

harkgar

Does MB make an oil dipstick for the 2005-2006 E320 CDi that stays in the hole and fits perfectly? If so I am rushing out to buy one.

harkgar

I had a VW Jetta TDi and never had any problem with injectors or water in the engine with regular servicing. In your experience is this a common fault with diesel engines? Apart from the water separator most diesel engines, including big trucks do not have any other means to get rid of water.

andys10

Thank you all for advises.
I will let you guys know what was dealer’s solution to this problem.
I will order dipstick during my visit to the dealer on Tuesday. Thanks again.

derek_cdi

First thing - here's what the service report states word for word. it took my service guys 5 days to figure out what the problem was.

"Customer states reduce oil level warning coming on at times. Check for codes - none found - preformed elec test on coolantg temp sensor, checked actual values of oil level sensro, version code ic to TAC spcs, drained oil to check amount then refilled to correct amount. performed interior can configuration test -ok- tested signal wire of oil level sensor - replaced oil level sensor."

Part number was 006-153-28-28

BTW, I have 26K on my '06 CDI.

No worries mate, it's just a sensor problem - it's not/not water in the oil. The oil level in your car is OK. They'll get it figured out.

KosherBenz

keep us updated, id like to know the outcome on this.


Best of luck with the dealer!

albania

mine has also this dark puff
any idea what to check?