Sorry for the delayed response all. I do not get email updates for some reason.
In response to all questions:
Originally Posted By: KrisZ
I would take up Mercedes on the premise that this engine was hand built by a highly skilled professionalno reason for this engine to crock out at less than 100k miles.
Good point, but I wont get anywhere with that. Completely agree
Originally Posted By: KGMtech
Check to see if one of the fuel injectors is leaking pressure.
Does the exhaust smell of unburnt fuel? do you smell gas in the oil?
All fuel injectors good, recently serviced. Oil doesnt smell of fuel. The exhaust scent is odd. Not quite a rich mixture, but doesn't smell oily either.
Originally Posted By: nicrfe1370
Alexander, in regards to the oil analysis report you showed us, which was from 3000 miles prior to this failure, iron was reading
very high at 101. [If you haven't spent any time exploring the Used Oil Analysis section of this forum, you would learn a lot there.] The lab claimed that all numbers were within normal limits, but I don't believe that at all. Even with hard use and an extended oil change interval I would expect the number to be easily less than 30, and possibly less than 15. Aluminum was also what I would call notably elevated. In addition, I would say that the difference between the compression of the known bad cylinder and the best cylinders is a noteworthy difference. When the engine is torn down, I think you'll find that cylinder #1 is damaged, and probably all three rings are as well. In your original post, when you listed the cylinder numbers and their compressions, which cylinder numbers are in the same bank as #1? I think it might be possible that half of the motor is having a problem. I would definitely not drive the car or even run the motor until a reputable shop has given it their full diagnosis.
On the plus side, that picture of the intake ports you showed us is remarkable! It literally looks brand new, as though there were fewer than a thousand miles on the motor. How is this car able to keep the intakes so clean?
I complete agree with your comments on the UOA. Not quite sure why they thought they where ok. That oil was Mobil 1, which I read has a high iron content on UOA. Even so, would expect it to be around 20 ppm! The oil also had very low mileage on it (2000 odd). I stopped driving the car as soon as it started smoking. Cylinders 1,2,3,4 are on the same bank. All the plugs on that side of the bank look rich, but not oily apart from no1. 5678 are all golden and good looking.
Originally Posted By: Astro14
That's a ton of oil on those intake valves. It's got to be pouring out of a valve guide to pool up there. It's not coming from the cylinder or it wouldn't be on the intake side of the valve. I think you've got a head problem: worn valve guide or valve seal.
I agree, but I'm not convinced its coming from valve guides or seals. There is oil sitting on top of all the valves, but no 1 is the worst. All other valves at the time of the pic, where slightly open so hard to compare.
Originally Posted By: Astro14
No. 1 cylinder compression is off by a bit, but not broken piston terrible. I'm pretty certain that this blower has its own oil supply. Something like 750ml, so it's not the blower making the engine smoke or foul the plugs - it would have run dry by now.
http://mbworld.org/forums/w211-amg/368922-diy-supercharger-oil-refilling.html
The OP mentioned consumption, and I think that consumption is through a valve guide/seal.
I'll check WIS later, but I think you're going to have to pull the head to repair this...and when it's off, you'll be able to take a look at the cylinder walls.
Hopefully, they're in good shape. The rings might be a bit coked up from all that oil burning, and a piston soak might help bring number 1 back up.
It is a tough one, would be easier if no 1 was down on compression a lot as it would be straight forward. The head is going to come off, but I'm putting a spare engine in it at the moment, as the car is planned for a European road trip soon.
I will then get the engine torn down and see what we find. My mechanic is so busy, he is not interested in getting the engine torn down as it will be hanging around his shop for a long time.
Originally Posted By: threeputtpar
Saw this car on justrolledintotheshop yesterday. Good luck with whatever it ends up being.
Thanks, will post a follow up once the head is off
Originally Posted By: Silverado12
A valve
seal won't cause it to use that much oil.
Its used approximately 1 Liter with idling and revving for approximately 40 minutes combined time whilst I was doing diagnosis.
Originally Posted By: AndyB
Is the motor mechanically quiet? I would think there would be some engine noise associated with large cylinder/piston damage.
Thanks,
Andy
Completely silent as always.
