phungpho

Darkman, oh by the way, I didn't see the cholesterol level in your test result

Back to the hot subject 'Break-in period with Synthetic oil'.
I guess SpeedyBenz has the point. It's better to break-in the engine with dinosaur oil for the first 1000 miles and then use synthetic after that.
Since many years, a lot of people (professional) think it's not a good idea to use synthetic oil during the Break-in period. They talked to Mobil 1, of course Mobil 1 said it's OK to use Synthetic... But, again, they don't have a clear awnser. Mercedes uses Mobil1 0-40 even for the break-in period!!! I guess, for new engine, with the new technology, there's 'almost' no need to break-in.
But, like Adam, I used the dinosaur oil for the first 1000 miles then switch to synthetic.
It's really interesting if I do a test and then compare the result with yours. One thing I am sure is my cholesterol is lower than yours because I go jogging everyday

patrick

The situation that engine oil should be changed after e.g. 1000 miles for correct breaking in is way behind. When leaving the factory the engines have already had a part of the breaking in procedure. When the FSS says to drive 15000 miles, just do it, but use one of the oils from the Mercedes pages with recommended oils, there are a lot of them.
We never have problems related to not correctly breaking in.
Patrick

speedybenz

In response to the question of what to do on a Nikasil bore when the bore wears out.

Well it is very hard to wear out a Nikasil bore. They are plated to a few thousands thick and the Nikasil is so hard you can not hone it with standard honing stones. It takes diamond hones to the job right.


But if you screw up a bore you can get it replated with Nikasil by Millenium Technologys or Lancourt, about $100 to $150 per bore.

Nikasil is great stuff, much better than cast iron.

Also the reason Syntechtic oil is not good for break in is that it lubricates too well and won't allow the rings to actually contact the cylinder bores which can lead to poor ring sealing.

Jeff

Darkmann

Jeff, now that makes perfect sense to me. Later today, I'll pick up a '02 ML320 and I have been wondering how to break it. As soon as I pict the car up, I have a 5Hr roundtrip journey to make - that's approximately 300+ miles. Then next week, I'm driving to Jacksonville, FL for vacation with the kids. I plan to take it easy 75-80 and I'm hoping that this will provide a good break-in without having to change oils. You think I should change the oil to fossil after the 300+ mile trip then back to syn after the Fl trip?

speedybenz

Darkman,

I would drive it normally for the first 70 to 100 miles and then change the oil to a good 10w-40wt , like valvoline. Then keep this oil in for the next 300 to 500 miles and this is when you take every opportunity to floor it to redline on every highway on ramp, or other safe places.

The goal being that flooring the motor or using full throttle will build maximum cylinder pressure so the rings will get pushed out to the bores and seat-in. And because the Nikasil lined bores are so hard it takes a little time. Do not be timid at this point. Run the **** out of it.

After the 300 to 500 miles, change the oil over to a good synth. like Mobil 1, 5-30wt. You really do not need to use a 40wt oil unless your WFO at 145mph for hours on end.

Your done. The motor should run like a top and not burn any oil for 6000 to 8000 miles between your oil changes.

Jeff

mleskovar

speedybenz....your recommendation is contrary to everything I have ever heard or read about breaking in an engine...."build maximum cylinder pressure so that the rings will get pushed out to the bores and seat in"!!!! What you are recommending will actually cause blow by - combustion gas slipping past the rings because they are not 'seated' yet, the very thing that you want to avoid during break in. High manifold depression is the main culprit leading to blow by and it is caused by excessive throttle opening in relation to rpm, commonly referred to as 'lugging' the engine. Any more opinions?

speedybenz

meleskovar,

Your are right the rings will let some combustion pressure past during this period but not for very long. As the combustion pressure gets back behind the top ring groove it will force the ring out against the bore. This happens every time the engine fires.

Now for your info. I can just say it wrong. I have several motors competing at AMA National roadraces every other weekend. If I am not at the event I watch them on the Speed Channel. Breaking in motor my way results in leakdown tests in the 2 to 3 percent range. What do your motor leakdown test at?

As such I have several close relationships with other engine builders and if you could ask them I know the answer. Run in the motor lightly for a few heat cycles then run it hard and change the non-synthectic oil every day.

As for lugging the motor being the cause, not really unless you have a poorly vented crankcase which won't allow the rings to push out to the bores. High manifold pressure only developes because the motor has the throttles closed and the motor wants more air so it creates the low pressure, but when you open the throttle at low rpm this low pressure goes away and on EFI motors the ECU will figure this out and restrict the injector pulse and still give you clean acceleration. But on a carb'd motor the momentary spike that the low pressure or vacuum gives to the carb creates a rich mixture which is hard to fire and can lead to detonation, until the carbs adjust to the airflow signal and meter out the right amount of gas which allows the motor to run smoother.

Do you have any more Questions?

Jeff

patrick

Why compare competition engines with engines for average use in daily traffic?
I sure believe that your leak tests results are in the 2 to 3 percent range, but these engines are not built to last several hundred thousand miles.

These competition engines are also often rebored so they are not really the same as standard engines leaving factory. The bore is really "new", which requires a different breaking-in procedure.
As I mentioned before:
Patrick

byip25

im so paranoid, i changed my oil @1000 miles. and have changed it at every 2,500 increment. i now have roughly 45K now...


B

patrick

Mercedes has a TSB that says that it serves nothing and is absolutely unnecessary to have an oil analysis done because of the fact that companies who do these analysises do not have proper standards or specifications. They just can make a report saying what they have found but they cannot make the right conclusions.

This sort of discussions lead to nothing:
The only one who knows how much Al, Si and many more there may be in the oil of certain engines is Mercedes itself.

Patrick

Darkmann

Of course, Pat, what were you expecting MB to say? Fact is that the FSS works as intended. Fact also is that a single oil analysis at $30 doesn't tell much. Fact also is that anyone can, at their choosing, perform an oil analysis, regardless of what MB or anyone else thinks. The point is that 13K first time oil changes on a new car are not common. I am a curious consumer and just wanted to find out how good the oil was after 13K miles, not the conditin of the engine - that I know 'cuse I'm still driving it and it works very fine, thank you very much!!! The condition of the oil can be assesed through a single cheap oil analysis - that's a fact regardless of any one else's opinion.