ML320 Stopped using oil at 95,000 Miles. Cant Understand.
 

Origional owner is my friend. Barry drove this 1999 new to 90,000 miles. He told me it used a quart of mobil one about every 1,000 miles since new. He also told me it took regular gas.
That Gas statement was honest ignorance.
So I bought it. Added a quart of Mobil one every 800 miles until 95,000. Then the miracle. This is what I changed....
Changed the oil and filter with Mobil One at 95,000 miles.
I've used premium gas since I bought at 90,000 miles.
At 94,000 I unplugged my ERG tube. (caked with goop).
I ran 2 tankfulls of Gumout emmission control cleaner thru it at 95,000 ish. And I add Marvel mystery oil to every tank.
Its been 2500 miles since the last oil change with no measurable oil consumption. I am stumped.
Can a plugged EGR valve cause oil consumption?
Remember it used oil since NEW.
Feb 15 2004 Update. to date..Over 150 people have read my post with no answer. I propose 1) the engine was never broken in and an oil ring on a piston broke free at 95,000 miles. OR 2) some emmission control valve never worked from the factory until I added additives with lubercants to the gas at about 95,000 miles.
3/23/04 update now at 3300 miles since oil change - still no measurable oil use. One mechanic told me the plugged EGR Tube would cause enough pressure in the valve cover to force blow by oil. AND even the too low octane fuel could effect oil use.
IT SURE MAKES ME WONDER how many of these ML320 engines were replaced by the dealer because of oil use...when it could be a simple emission control problem.
4-19-04 update. 3,550 Miles since oil change. No oil added. Oil finally shows a 2/5" drop on the dip stick. Still in the safe area.
5/21/04 at 4200 Miles since change, Oil Light came on. I only added 1/2 quart as I will be changing at the 5,000 mark from now on.

Question - if you bought this vehicle new from the dealer, would you accept 1 qt / 1k miles? I sure wouldn't. Perhaps your friend's statement is excluding the first 30k miles or so.

Steve

Barry said the dealer told him any oil use of less than one quart every 700 miles was acceptable to Mercedes.
So Barry lived with it.
Barry loves his new 2004 Lexus RX.

Oil is not for burning, or for leaking
 

At that rate you could run dangerously low on oil before an oil change. I'd accept nothing more than a 1 quart add per oil change if doing 3K mile oil changes and maybe 2 over 7.5K miles. Anything more is way too much, and probably indicative of bad valve stem oil seals, or in extreme, bad ring sealing.

My '93 600SL uses 1.25 quarts over 7.5K miles, just so you know where I'm at, and that's at 82.5K miles.

Justin rules
 

You wouldnt accept that the dealers rule book ?

Most Auto manufacturers warrenties wont kick in when a car uses 1 quart or less per 1,000 miles. Their rule books say that is acceptable.

How do you not accept it ? With a lawyer ? A hand Gun ? :confused:

Hell no that is NOT an acceptable oil consumption rate. That would mean that for any road trip (with a '99 !!!), you would have to carry around extra quarts of oil?? And that oil is carboning up your compustion chambers, exhaust valves, and cat. Bad juju. That just means that they don't want to invest the shop labor into fixing it, its your problem, not theirs.

Yeah, the EGR was probably the culprit. Surprised that wasn't caught earlier. If it isn't working right, then the crankcase will pressurize, and cause blow by the oil rings on the pistons, as well as thorugh the valve guides.

Other than loosening up a sticking hydraulic lash adjuster or freeing up rotor seals on a rotary engine in an RX-7 (Boy was that an IMPRESSIVE bit of smoke after I restarted it!!) , I've never really seen MMO. make any significant change to a motor's performance, or lack thereof, and I've heard of other oils used to do the same thing, such as ATF.

When it comes to dealer (non)service, I never trust them, not a word, until I verify it myself. More times than not I have caught them in outright lies, and even pointed out service bulletins to them that made my case. Always do your own research. I once got a GM service manager fired in Tennessee after I spent $450 on repairs that still didn't fix the problem. I researched, found the service bulletin, and called GM's regional office on it.

I'm very glad that god made me a mechanical engineer, and gave me the skills to turn wrenches. Good engineers are born, not made...its all genetics :D

Strider -
 

So the answer is --you would go over their head and get them fired --.


You say -- Mechanics are born - its genetic's ,,,,

I think that's a major part. I assume you are of German heritage...

Is your handle "Strider" for ST Rider ?
Many Engineers Ride ST's.
Ive had my ST1100 for 5 Years- now over 50,000 near Flawless Miles.

Sounds like your ML didn't stop using oil but rather dosn't use as much oil.

You didn't state which weight of Mobil 1 you use. Mercedes only recommends 0W40 or 5W50 for the Mobil 1 products. During the cold winter months I recommend 0W40.

On previous non-Mercedes cars, I had good luck with Rislone oil treatment.

Oil Consumption Update - Radio Host Talked To Me
 

I now have 5500 miles on my ML320 since my last oil change with the level just fine. I spoke to our local Car talk guy on WOOD AM Radio..
He said I did exactly the right thing. Because the origional owner used regular, there was emmision blow by that deluted and thinned the oil and thus oil consumption.

So by me cleaning the emission control parts, using gas additives, fresh Mobil One and Mobil Premium Gas - I cured it.

He thinks I should change it more often than every 7500 miles however.