W208 CLK55 Oil check warning

[stereophoney]

Had my 55 for a couple of months now and still loving it, really quick and I got 24.3mpg on a 225 mile run!

One thing that is bothering me is the oil check warning. After 15mins of driving the 'check oil level' message comes up. If I pull over and switch off the display shows 1 malfunction, but won't show what it is. Turning the key to position 2 results in this message disappearing. If I do the oil measurement check it almost always says 'OK'. Sometimes it state 'Perf Serv ontime' and once it told me to 'add 2 litres'. Checking manually on the dipstick it has never been low. On a cold engine the level is a touch below max. It was changed by Mercedes about 600 miles ago. Once the oil is up to temperature it never comes on.

Does this sound like a sensor issue? If it is I understand the sump needs to be dropped, if that's the case I plan to leave it until Feb when it's due to be changed and sort it out then. I assume there's nothing wrong with that!

 

[Auto-mobile]

Sensors are a common failure with the symptoms you refer to, sump off job, bit of a job to get it of as its bonded on.

 

[sspeed]

Try This..

Oil Check Procedure.​

Note: If the engine has just been running, let the vehicle stand for around 10-15 minutes before starting this procedure.

1. Make sure that your display in your cluster is set to the default Mileage and Trip distance, then turn ignition off..

2. Turn off ignition and now turn to position 1

3. Press the 'Reset' push button on the extreme left-hand edge of the instrument cluster quickly 3 times. The Voltage should now be displayed

4. Turn the ignition key clockwise from position 1 to position 2 (second position).

Press the 'Up Arrow' on the left of the steering wheel ONCE. Hopefully it will show 'Oil level _._l' in the central display area)

Wait for 10 seconds or so for the oil reading to take place.. In my case C270 Cdi the capacity is 6.5 litres..
This method is MUCH more accurate that the "Add oil" message

 

[stereophoney]

Tried the above, but doesn't seem to work on mine.
The 'check level' warning is still coming up on every journey, always at the time when the coolant temp has just got above halfway. Today I got an 'add 2l' message and then 'visit workshop'.

I stopped and left it a few minutes, the checked the dipstick level. The level was halfway between min & max, though on a cold check the level is just below max. I drove home, switched off and did the electronic check and it was back to 'ok'.

What confused me is the fluctuating level. I would have expected an increase in level when warm.

 

[rawc43]

Tried the above, but doesn't seem to work on mine.
The 'check level' warning is still coming up on every journey, always at the time when the coolant temp has just got above halfway. Today I got an 'add 2l' message and then 'visit workshop'.

I stopped and left it a few minutes, the checked the dipstick level. The level was halfway between min & max, though on a cold check the level is just below max. I drove home, switched off and did the electronic check and it was back to 'ok'.

What confused me is the fluctuating level. I would have expected an increase in level when warm.

the best time to check oil level is first thing in morning when all the oil is the sump. if the level is juts below the max at this time then you may need a oil level sensor its a easy job to change it

 

[sspeed]

Tried the above, but doesn't seem to work on mine.
The 'check level' warning is still coming up on every journey, always at the time when the coolant temp has just got above halfway. Today I got an 'add 2l' message and then 'visit workshop'.

I stopped and left it a few minutes, the checked the dipstick level. The level was halfway between min & max, though on a cold check the level is just below max. I drove home, switched off and did the electronic check and it was back to 'ok'.

What confused me is the fluctuating level. I would have expected an increase in level when warm.

Ahh if you have a dipstick then the method above wont work..
My current car has a good old fashioned dipstick..
The level does indeed expand a bit when warm..
Whenever I replace my oil and filter I always fill to the upper level and its always fine and never gives a warning to "remove oil".
I do find though that I need to dip the dipstick several times because the oil sort of blocks the dipstick tube and you get a false reading..
Dip and wipe 2 or 3 times before taking an actual reading.

 

[Bakili]

Where can I get dipstick for W211 e320cdi?
If engine cover removed, i can see on right red plug like thing, looks like oil dipstick, is it where dipstick goes?

 

[sspeed]

Errr that is the dipstick.. lol
Give it a pull up and all will be revealed..

 

[Bakili]

Errr that is the dipstick.. lol
Give it a pull up and all will be revealed..

I pulled it, and it is just plug, no stick behind it lol.

 

[sspeed]

I pulled it, and it is just plug, no stick behind it lol.

How very strange??
Well yes it is the dipstick tube...
Use my reg number when you order the part as mine 100% definitely has one..
Even Mercedes cant charge much for a damned dipstick...
Can they ?

Is yours the V6 Diesel ??

 

[Bakili]

How very strange??
Well yes it is the dipstick tube...
Use my reg number when you order the part as mine 100% definitely has one..
Even Mercedes cant charge much for a damned dipstick...
Can they ?

Is yours the V6 Diesel ??

its 320cdi 2003, i believe I6

Not sure, if it is true, but read somewhere, you cant keep dipstick in on cars not equipped with dipstick. You can buy one, but only to read oil level in engine.

 

[sspeed]

Have you tried the dashboard service mode method??
See no3 on this post

 

[Bakili]

Have you tried the dashboard service mode method??
See no3 on this post

Will do tomorrow
Thanks Simon

Looks like £35 suitable dipstick for my car, and must be removed after checking oil level.
I wonder id V6 has same type dipstick, it would be probably cheaper to get from breakers.

 

[rawc43]

Ahh if you have a dipstick then the method above wont work..
My current car has a good old fashioned dipstick..
The level does indeed expand a bit when warm..
Whenever I replace my oil and filter I always fill to the upper level and its always fine and never gives a warning to "remove oil".
I do find though that I need to dip the dipstick several times because the oil sort of blocks the dipstick tube and you get a false reading..
Dip and wipe 2 or 3 times before taking an actual reading.

the method I use is using a dipstick witch all w208 clk55s have

 

[stereophoney]

Had a look at prices for the sensor. Best I can find for a new unit is £85 from here, hope it's the right one: SENDER UNIT - E Class 1985 - 1994 E250 - Mercedes-Benz Parts, Inchcape

Is the consensus that I should trust the cold dipstick reading which is at max? Other than a faulty sensor is there any other possible cause?

 

[BlackC55]

That is not correct. That is for an old 124.

Just get one from MB. It will have a 2 year warranty too. You will also need some of their black sealant as the sump has to come off when you replace it.

 

[stereophoney]

That is not correct. That is for an old 124.

Just get one from MB. It will have a 2 year warranty too. You will also need some of their black sealant as the sump has to come off when you replace it.

Thanks, I think that's just an issue with the Inchcape website, when you type in a part number it seems to default to 124 is the search box. The part number I hope is correct for mine!

 

[brucemillar]

Get your car checked properly. I had overfill followed by under fill messages.

Threw a piston threw the block. New engine required.

Moral of story. Get it checked.

Mine was a blocked oil passage.

 

[BlackC55]

+1 if the sensor is faulty a code is normally present. Also the sensor value can be observed with live data.

 

[stereophoney]

Plugged in OBD2 scanner, but it doesn't detect any codes when the 'check level' warning appears. Also the check engine light does not light up, though on the scanner it shows that it's off.
Is it possible to stop codes appearing using STAR? My worry is that I bought it from a mechanic who worked at a Merc dealership who would have had access to STAR. If it is possible would a footprint of who did the work be left?