Running in a diesel

[Dieter]

Hi,

I'm sure there are/have been lots of threads on this issue but I couldn't find a specific one so I apologise in advance for starting another (redundant) thread .

I appreciate that nowadays most new engines require little running in (unlike those of yesteryear which soon filled sump with iron filings etc.) but I seem to remember that as modern (especially synthetic) oils are so good that 'normal' running in (< 3500 rpm for first 1000 miles) may result in glazed bores etc. I vaguely remember a school of thought that short spells (non-laboured) of high revs in the first hundred miles or so prevents this?...or I could be typing a load of 'tosh'

Any comments anyone?....Dieselman

Cheers,

 

[yachtman]

the worst thingfor a new diesel is excessive low power demand, as leads to bore glazing. so dont warm it up idling on the drive first! get in and drive, as soom as oil pressure is up, and steady.

personally a believer in never more than 3/4 of full revs for 2000 ml, then occasional forays intothe upper echellons of power when well warmed.

Yacht diesels are a good example of owners ruining their engines with loving careful warm ups, that lead to premature failure.

 

[renault12ts]

You Jag will not show oil pressure. Get in and drive. Diesels run cool naturally so you can't warm them up in the real sense on your drive. Modern engines and oils are very good. Don't gun it, but don't nanny it either.

 

[oldcro]

One thing I was taught about running in a car (remember it is not only the engine that needs running in) was to drive in hilly areas as much as possible. This allows the pistons to both drive and be driven when on over-run. Meant to even out the wear on the bores for better seal between rings and piston sides. If on a long motorway type journey just take our foot off the accelerator now and then, letting the wheels drive the engine.

I'm not sure if this does make a difference, particularly with the tighter tolerances of modern engines, but none of my vehicles ever suffered from any faults related to engine wear.

 

[Uberwagon]

One thing I was taught about running in a car (remember it is not only the engine that needs running in) was to drive in hilly areas as much as possible. This allows the pistons to both drive and be driven when on over-run. Meant to even out the wear on the bores for better seal between rings and piston sides. If on a long motorway type journey just take our foot off the accelerator now and then, letting the wheels drive the engine.

I'm not sure if this does make a difference, particularly with the tighter tolerances of modern engines, but none of my vehicles ever suffered from any faults related to engine wear.

The best way to do it imo.

Just drive it as normal and don't do any one thing for long periods, so no long motorway or town drives. Just go and enjoy it.

Dave!

 

[johnsco]

I'd recommend varied driving with high and low revs for the first 1000 miles or so.
If it's a manual transmission, don't lug the engine in too-high a gear.
This applies at any time, but especially in the first period.

Maybe I'm old-fashioned.
I know a number of friends who just don't bother, and take the view that a car is there is to be driven, and to get in it and enjoy it.

But then - They don't do their own maintenance work !

 

[BTB 500]

I personally do what it says in the handbook.

For the Vito this is

Running-in

It is of decisive importance for the operating life, reliability and economy of the vehicle that the engine is not subjected to its full rated load during the running-in period.

Up to 1,500 km

• Run the vehicle in carefully. Drive at varying road and engine speeds.
  
• Avoid heavy loads (driving at full throttle) and high engine speeds. Do not exceed 3/ 4 of the maximum speed available for each gear.
  
• Change gear in good time.
  
• Do not change down a gear manually in order to brake.
  
• Avoid depressing the accelerator pedal beyond the pressure point on vehicles with an automatic transmission (kickdown) and only engage gear 4, 3, 2 or 1 while driving slowly.

After 1,500 km

• Gradually bring the vehicle up to full road and engine speeds.

These instructions must also be observed if you have the engine, the transmission or the rear axle differential of your vehicle replaced.

 

[NewMB]

Do like the germans...... pedal to the metal from day 1.

If anything breaks, you are covered under warranty.

Good point, but at the same time not something I would do as you have an engine and a gearbox that are put together for the first time at the factory and never used together before (like a marriage) and needs to agree with each other.

 

[st4]

Noting BTBs post 3/4 engine speed is 3000rpm. In dieters new car this probably won't be an issue every day as it should be powerful enough to change up at 2k rpm whilst being able to keep pace with traffic. 3k rpm in top gear in my car is about 90mph, and in dieters more powerful car with a higher top speed I imagine this to be in excess of 100mph so not really an issue.

His car is an automatic so the foot brake is the primary source of braking anway, so long as the "paddleshifts" are left alone in practice the car can be driven pretty much as normal.

 

[jeremytaylor]

I don't like BTB's post on the Vito running-in instructions, specifically the last line. It looks like MB are expecting major engine/drive-train failures!

 

[lynall]

I don't like BTB's post on the Vito running-in instructions, specifically the last line. It looks like MB are expecting major engine/drive-train failures!

They are my last boss had one, it had a couple of gearboxs, at least one diff plus loads of others bits in the end after approx a year they took it back for another one.

I bet he never mentioned the fact i backed an eight wheeler smack bang into the front of it cost 5k to fix.



Lynall

 

[timskemp]

It's always been my opinion that the "take it easy when new" running in instructions are manufacturers covering themselves for manufacturing faults - you're going to notice something loose or missing more on a new car and more if driving it gently. Also tyres and brakes need bedding in too (though that can be sorted with powerslides and emergency stops...) and don't perform 100% until a few miles are on them.

Lots of stories of other brands (GM) diesels suffering high oil consumption from bore glazing caused by not driving properly (ie hard...) from new.

 

[FaeLLe]

This is Mercedes official run in instructions in case anyone looks for this in the future - http://moba.i.daimler.com/baix/cars..._43.shtml:ID_24cf11510f6394ed351f19153a83d389

Running-in notes
Important safety notes

In certain driving and driving safety systems, the sensors adjust automatically while a certain distance is being driven after the vehicle has been delivered or after repairs. Full system effectiveness is not reached until the end of this teach-in process.
Brake pads/linings and discs that are either new or have been replaced only achieve optimum braking effect after several hundred kilometres of driving. Compensate for the reduced braking effect by applying greater force to the brake pedal.
The first 1,500 km

If you treat the engine with sufficient care from the very start, you will be rewarded with excellent performance for the remainder of the engine's life.
Drive at varying road speeds and engine speeds for the first 1,500 km.
Avoid overstraining the vehicle during this period, e.g. driving at full throttle.
Change gear in good time, before the rev counter needle is of the way to the red area of the rev counter.
Do not shift down a gear manually in order to brake.
Vehicles with automatic transmission: try to avoid depressing the accelerator pedal beyond the point of resistance (kickdown).

Additional running-in notes for AMG vehicles:

Do not drive at speeds above 140 km/h for the first 1,500 km.
Only allow the engine to reach a maximum engine speed of 4,500 rpm briefly.
After 1,500 km, you may gradually accelerate the vehicle to full road and engine speeds.

Info:

You should also observe these notes on running-in if the engine or parts of the drive train on your vehicle have been replaced.

AMG vehicles with self-locking rear axle differential

Your vehicle is equipped with a self-locking differential on the rear axle.
Change the oil to improve protection of the rear axle differential:
after a running-in period of 3,000 km
every 50,000 km or 3 years

These oil changes prolong the service life of the differential. Have the oil change carried out at a qualified specialist workshop.

 

[pmw103]

Hi FaeLLe,
Thanks very timely I pick up my car on the weekend.
I am been wondering / worrying about this.
I have some trips coming up that I normally do on the motorway.
Do you think its ok to drive on the motorway during the running in period?
If you vary the speed between say 65 and 75 or is that not enough?

Did you get your car already? How are you running it in?

Thanks
Paul

 

[Dryce]

I am been wondering / worrying about this.

Suspect you're worrying about nothing.

I would relax and just drive the car with some care as regards revs but otherwise at normal traffic speeds. The suggestion by MB to limit revs and not depress the accelerator beyond the kick-down pressure point sounds relatively straightforward.

If you ask the question about running or breaking in there's a whole raft of opinions and theory and stated experiences. Most of which are probably at best out of date and and worst total b*ll*cks.

 

[flango]

Do like the germans...... pedal to the metal from day 1.

^ This. I have done this with all my cars petrol or diesel never had an issue with carbon build up, excessive oil consumption, poor fuel consumption.

My theory is when you build a race car engine you don't take it out on track and run it in, you give it all its got, so I do the same with my road cars.

My new Golf has had 3k of extreme motoring so far

 

[Deleted member 6183]

I'd say just drive it.

If your driving style is hard enough on the car to cause problems during running in then the chances are that you will cause damage later on anyway.

 

[Deleted member 6183]

^ This. I have done this with all my cars petrol or diesel never had an issue with carbon build up, excessive oil consumption, poor fuel consumption.

My theory is when you build a race car engine you don't take it out on track and run it in, you give it all its got, so I do the same with my road cars.

My new Golf has had 3k of extreme motoring so far

I drove a company car Golf Gti from new in 1989, when I picked it up the dealer said just drive as normal - I was in my early 20s then and 'normal' was a little more boisterous. The car was passed on to other drivers and they all commented on how well it went.

 

[pmw103]

Hi everyone thanks for the super quick replies, I am quite sedate driving wise anyway so will just drive as normal then and not make too much of a point of avoiding the motorways then. Thank you! It was just the varying road speed bit that caught my eye re the motorways, thanks again! take care p

 

[Dryce]

My theory is when you build a race car engine you don't take it out on track and run it in, you give it all its got, so I do the same with my road cars.

How long does a race engine last? How likely/often is it to be stripped and rebuilt?

OTOH how many engines installed in a production car these days will ever have even just the heads taken off?

I think the wide ranging spectrum of tales ranging from italian tuneups to geriatric sunday afternoon driving combined with the time/mileage to first service indicate that to a degree it doesn't really matter too much given the quality of manufacture.