I pick up my ML63 tomorrow afternoon
I'm sure the salesman will tell me how he thinks it should be broken-in. I am curious what break-in procedures have been advised to other people at this forum by their dealers. I wan't to keep this one for a long time!
TIA

 

I have discussed this on other forums so to save me retyping, here is a link to a past thread. See my post (steved) on the first page.

http://www.z4um.com/viewtopic.php?t=...er=asc&start=0

I applied the same approach with my ML63 (now at 1100 miles) and it always works a treat.

I usually receive comments along the lines of "why did the manufacturer quote a run-in procedure if it wasn't required?", but you need to consider who the 'average' owner of these cars might be and then it begins to make sense. In the world of racing we don't run-in engines (in terms of handling them with cotton wool) but we do 'bed' them in and bedding in is a much more assertive action.

Key thing to bear in mind is to ensure the oil temperature is up to normal and be mechanically sympathetic but firm.

 

Thank you Doctor D
That is how i was hoping to break it in!

 

would it be bad if i just drove the car normally and didnt do the above procedures. I'm sure the volvo that the guy drove for a few million miles didnt follow that procedure. is it bad if i just drive the car normally, and dont follow that procedure?

 

It depends on what you are aiming to achieve.

You first need to dis-associate the task of running and engine in with 'treating it REALLY gently', the engine is a machine and as such you need to understand what it does and how it does it. It used to be necessary to cure gaskets and seals, but not any more.

Running in these days is more a matter of 'bedding in' the frictions surfaces (i.e. clutch, pressure plate, brake surfaces etc) and mating the piston rings to the cylinder bores. The piston rings are only able to achieve this during the first few hours of use, thereafter the sharp edges become worn and the clearance between rings and bores will now be set for the lifetime (thereabouts) of the rings.

If these rings were badly matched to the bores then in a worst case scenario they may end up allowing oil to pass into the combustion chamber, more likely the seal made by the rings will be less optimal than if they'd been bedded in properly and therefore the combustion pressure will be less (i.e. the engine will produce less power and be less efficient). This matters to some of us more than others, but it seems a shame to buy a 510bhp engine and then squander 20bhp through poor running in.

The concern most people have is that by being more assertive with the running in procedure they might harm the engine, well that simply is not likely provided you wait until the fluids are up to operating temperature and therefore the engine is adequately lubricated.

Most manufacturers run in their engines during production, and some (i.e. Porsche) advise no running in procedure whatsoever. Either way it's worth realising that the standard running-in instructions in your handbook apply to a wide range of customers including those who might live in arrid regions of the world, use poor quality fuel and never check their engines. So these instructions err on the side of very cautious. They mean well and if you ever get the chance to talk with an insider (i.e. a development engineer) you will soon discover how the manufacturers themselves choose to run-in their own cars.

 

sorry for asking so many questions but, when i am first driving the first twenty miles of a car, am i supposed to be opening up the engine by using the whole power band, without taking it straight to the red line?

on a side not, if i take my car to 5 or 6K rpm everyday, wont my transmission have a greater chance of breaking down? or is it okay to drive a car like that, as long as i keep the car lubricated?

 

Precisely. Use the whole power band stopping around 1000 rpm shy of the rev limit and making sure you don't labour the engine at low revs, but make sure you accelerate strongly through a 5000 rpm range - and picture what your piston rings are doing to mate with the shape of the bore. The key thing is to ensure the engine oil is at normal operating temperature and therefore is providing adequate lubrication to all moving parts in the engine.

The transmission is designed to be used throughout the rev range, therefore it won't break down, but you do need to bed in the friction surfaces for the first few hundred miles of use, so whilst running in the engine it's important that you don't inadvertently trigger kick-down through several gears. Moderate change down is fine, but you want to be treating your auto transmission slightly more gently than the engine when bedding in.

 

what about when i am driving the car after the break in period, like when it has 80K miles on it, is it hurting a transmission when i floor it everynow and then? or are trannies designed to be driven like this as long as it is lubricated?

 

You just have to be mechanically sympathetic and make your own judgement based on the condition of the car, when it was last serviced and ensure everything is properly up to temperature.

 

well, i have a 2003 maxima with around 85000 miles. I have always properly serviced it, and everything has been great with no problems. some people say that the car will break down before 100K miles if i drive it spiritedly.

 

Doesn't AMG test the engine before it leaves anyways?

I mean I was told that the break in is more for the rest of the car, not the engine.

 

yeah it does, but it doesnt hurt to do it yourself too.