Hey guys - Since yesterday I have been noticing ALOT of weird (almost like something is broken) knocking sound. It was so bad that I had to stop and pop the hood to see if something was broken. Didn't see anything broken. Since I open the hood while the engine was running, I assumed that there maybe a tear in the belts or something. But tonight, I had to pop the hood again and after carefully listening to the sound inside the garage, I noticed that the sound was coming from the right side (while you are facing the engine - hood open) under that big black cover that covers the engine block and that has mercerdes emblem. I will look a little more in the AM but any ball park advice would be appreciated. BTW: I have been getting check oil sign really frequently... that would go away for a day or two after poring quart of oil but than check oil sign would come back - The weird thing is that, when I check the oil level throught instrument panel it would show me "oil level ok"... Help please.

 

take a video of the noisy engine and post it.
As for the oil, when was the last time you changed the oil? How many miles on the car?

 

Remove the black MB plastic cover/aircleaner and look under it for problems.

 

Observe serpentine belt tensioner.

 

Honestly I don't remember when was the last time I changed the oil - I have been putting quarts whenever I see the message.

I have 125K miles on this bad boy - bought it in June 2007 with 39K miles. Wow!!! In 3 years, I have clocked almost a 100K.

I'll be uploading the video shortly

How and where do I buy the dipstick?

 

The information I was able to find was that, I created a makeshift dipstick and after putting into the check oil tube, about 5 inches of the stick came out dirty with oil.
How high should the oil level be on a dipstick when the oil is at full level (8.5 qts)?

 

Upload the video to youtube.
Don't tell me you haven't changed the oil for the past 100k mi. You're not joking, right?
The engine does not normally burn oil. If you need to pour in one qtr here and there, it's very likely there's a leak somewhere -- valve cover, rear main seal, etc.
You should change the oil right away and look for leaks. Oil change interval should be around 8k - 10k mi.

 

@SZMB; Yes unfortunately that's true, I did not change the oil in a very long time... here's the youtube link:

http://www.youtube.com/watch?v=7xV08j3O_F8

I did however change the oil yesterday, and glad to report that the knocking/thumping (whatever you call it - it sounded like diesel engine) is gone.

Sadly, I have to report that, while trying to drain by suction method, less than 1/2 qts came out. That was really surprising to me so I pored fresh oil (about a qt) into the engine and the suction pump started to suck the new oil out (that was the indication that there was unfortunately NO oil (less than 1/2 qts) in the car)

I did end up dumping about 8.5 qts of 0w40 mobile 1 into the engine and took for a spin before the knocking sound was gone.

Now here's the ticker - after driving for about 10 -/+ miles, I have the "check engine oil/low" message again. I checked the oil and the console says "oil level okay" and this time I checked the oil through a make shift dipstick and it gets dirty with oil for about 6"... The Weird part is that, every time I got this message in the past, I checked the oil through the console and every time it said "oil level okay" except a few time it asked for a qt and filled it with a qt.

I know I have been pushing my luck starving the car for the oil but the oil sensor is a little koo koo and not having dip stick didn't help either. What do you think guys?

Oh and as for the leak, I don't see any on the bottom, except I see a lot of oily crud in the front parts of air filter and black cover, what is that mean?

Also, my son can't open the passenger side rear door through the door latch even though the car is unlocked and the lock lever is all the way up.

Passenger side front lock lever goes up and down 3 or 4 times ever time I try to lock/unlock the car and takes a few tries before it locks/unlocks... what is going on with my locks?

I know too many questions - Sorry but someone please try to answer them... We can't take the care to STEALERS due to personal reasons, hence MBUSA.com and all DIY help. (125K 04 - 4matic E320)

 

After looking at the video, it does sound like the knocking sound is from the engine and not the bearing or the pulleys. It sounds like the lifters begin showing some wear. It's a common problem in engines w/ long oil change intervals. It's a good sign that the knocking sound is gone after changing the oil.
I still couldn't believe that the engine only had 1/2 qtr of oil. The engine could had been destroyed by now if it had only 1/2 qtr.

BTW, did you change the oil filter?

I would redo the oil change just to be sure the oil level is correct. Drain the oil from the oil pan drain hole, and not use the suction tool. If you're not comfortable working under the car, take it to an oil change shop. Bring your own oil and oil filter. They normally change $39 for labor. Put in exactly 8.5 qtrs. If the message "low oil level" is till showing up, it's very likely the oil level sensor is faulty.
If you want an accurate oil dipstick, call the dealer to see if they carry it for your model.

If you haven't changed oil for a long time, i guess you have not done any other maintenance for the car either. At 125k mi, the list is pretty long...

 

Forget the stealer .. why can't you even take it to a indep shop?

DIY .. the first word of DIY is "DO" which you aren't doing. Either you do it, or take it to an indep shop and let them do it, but you can't abuse the car like this and expect it to last forever.

If you can't afford to maintain the car, sell it and get something you can afford to maintain.

It is totally ridiculous that it has come to this with your car.

 

Wow! you're the luckiest man alive!

You should plan a vacation in Vegas.

 

It pained me to read this

Take care of your car (in the future) if you expect your car to take care of you. I agree, find a good Indy who can do the maintenance for you.

I really pity the person who buys this vehicle from you... I guess this is why you should inspect the service records before buying a used car...