Run in procedure on new vehicle?

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Gaz-M

Active Member
Joined
Dec 10, 2015
Messages
116
Location
Fife, Scotland
Car
17' Flint Grey Vito 116 Auto
What is the run-in procedure on a new motor, I have a new Vito (2.2cdi 163bhp) going on the road 1st March (next Wed)?

I surely want to put some miles on the engine before I go booting it or towing my trailer!?

Wasnt there an early oil change on new motors too?
 
You should get guidance on this from the dealer when you pick it up ; there will also be advice in the handbook , which I'd be more inclined to follow than the opinion of some salesman .

I don't think it is as stringent as in days of old , but I'd avoid maximum load / engine speeds for the first thousand miles or so , then build gradually from there .

There was indeed an early oil change in days of old ; don't think this applies now , but of course absolutely no harm in it if you want to do that yourself .
 
The manual just says take it easy for 1500 miles, I wanted some specific guidance on our new C350e as being a hybrid, it is a bit more awkward to control when the ICE actually runs (unless you run it in sport all the time). As it happened, I had a courtesy call from the dealer and asked them the specific question. Short while later got a callback from them and got a somewhat equally vague "just go steady for the first 1000 miles". There isn't an early oil change either, so that all suggests to me that the cams and rings have already beeen bedded in before the engine comes off the line, or, they simply don't bother (or need to) any more.

Does feel a bit vague and unsatisfactory lacking any genuine statements though.
 
Yeh thats not ideal. Even worse because my van will be towing a loaded car trailer so I want to run it in before I do that.

Think I will do 1000miles and just bear it in mind when towing for a while after that?


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Don't labour it is the main thing, but it is much better to give it plenty of varied use, than *****ing around at low revs and low speed.
 
I used to work in the car sales trade for 6 years about 10 year ago, believe it or not all of the courtesy cars were fault free as they had been blasted from day 1, ragged about and thrashed, always drove really well lol

We always used to say keep revs under 3k for the first 500 miles then drive Normally for 500 varying the revs.

There have always been arguments for caining an engine as soon as you get it to bed it in, personally i think just drive it normally these days.

I do think the first oil change is still as important as ever, no about of machining and tolerances will make all the parts fit perfectly, I'd still dump the first oil change at 1000 miles and go from there.

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I think I'm just going to assume that the vital bits like rings & cams are done in production these days, then just take it a bit steady, with increasing and varied loads as much as possible to ease the rest of it in - crank bearings really.

As CC says, don't labour it is the main thing. Trouble is, that's sometimes tricky to achieve when the darn things keep wanting to get into as high a gear as possible all the time. For now, I'm tending to drive mostly in Sport, just to keep the ICE running, but that is specific to the hybrid, although thinking about it, that will also tend to keep it in one gear lower anyway for all auto models so probably a good idea for break-in/running-in. Few more revs, bit less load - ideal.

Would be grand if someone in the know could give a definitive statement about this sort of thing, but then I guess MB probably consider it something that 'Sir doesn't need trouble himself with'.
 
Yeh its an Auto aswell so a bit harder to vary the revs myself! Will take it a good old run next weekend and put some miles on it.

Will change oil at 1000miles or so too I think!


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As others have already said, don't let the engine labour and don't use full rpm for any length of time initially, but instead try to vary load and speed gradually building up over the running in period to full speed and load.

Diesel engines don't respond well to running in solely under light load. You need to load the engine up a bit in the early days to promote piston ring sealing. Be too gentle with it and the bores will glaze and it will forever use oil.
 
A theory behind the success of an aggressive running in regime is that piston rings work by combustion gas pressure getting behind them and forcing them into good contact with the cylinder wall. If an engine is a babied at low revs the rings don't get to work properly and the cylinder glazes up before the wearing in process has completed. Modern engines built to fine tolerances have less of an issue but low revs exclusively should still be avoided.

Consider how the bearings are lubricated. Keeping the bearings from metal to metal contact has very little to do with oil pressure as the forces involved are magnitudes higher than the oil pressure. It's hydrodynamic lubrication that maintains an oil film wedge in the bearing and that depends on peripheral speed of the bearing surfaces. Keeping the revs up will ensure good lubrication. I'd vary the revs when running in, avoid loading the engine at low revs and use bursts up to at least 3000 RPM .

Lubrication of engines that develop maximum torque at ridiculously low revs must have been quite a challenge for engine designers. One way they do it is by increasing bearing journal diameters as that will increase peripheral speed at any given revs.
 
I'd suspect that what's changed over the years is the accuracy of machining in the manufacturing process. Running-in (in the old days) was about components that didn't fit 'quite right' having accelerated wear cycle so they did fit right. The bits that were 'worn off' finished up in the oil, hence the oil change at 500/1000 miles.

The much greater accuracy of machining in current manufacturing proceses means stuff is much closer to being a good fit from day 1.

All that said If I purchased a new car I'd follow the advice about not labouring the engine, not thrashing it from the start and varying speed/load and do an oil change at 1000/1500 anyway. Other then the cost there isn't a down side to that oil change.

Old saying in the motor trade "Oil is cheap, engines are expensive'.
 
Thrash the nuts off it. That's what MB engineers spend billions of pounds on. It's a commercial engine designed to be worked from day one.
 
I thought the standard run-in advise was to 'drive the car moderately using all of the available rev range'?
 
Thrash the nuts off it. That's what MB engineers spend billions of pounds on. It's a commercial engine designed to be worked from day one.

I was more or less told the same thing. Drive the car as you would normally, although don't put excessive load on the engine, which means leave the caravan at home.

Unlike cars made forty or fifty years, modern cars are already machined to an exceptionally fine tolerance and modern engine oils are designed for coping with all driving styles.

In other words, drive as you normally would. You'd have to really thrash a modern engine to do any real harm. Oh, and stick to the service schedule.
 
I think the key point is don't labour the engine, flex it through the rev range increasing the max RPM gradually over the first few miles and heat cycles. After this just drive it but make sure it gets a few hard runs occasionally once up to temperature.

Diesel engines will thank you from some excercise - I would take on board the good advice about glazed bores and oil usage.

In reality - I don't think you'll hurt anything no matter what you do, over it's lifetime a modern Diesel engine is more likely to suffer from other faults aside from the main engine components. You've got a warranty for a few years, relax! :)
 
There's also plenty of evidence that modern ECUs will limit performance to a degree for the first few miles as well.

Engine's I have built myself using what are really old school techniques and tolerances I've done the bed the cams, bed the rings, change the oil all done in 50 miles techniques, but a modern production car is a different animal.

I also think that the amount of money one has personally invested and how long you intend keeping the car might colour the view on the whole thing as well.
 
Thanks for opinions and advice.

Out of curiosity why does everyone say to avoid low down load?


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Thanks for opinions and advice.

Out of curiosity why does everyone say to avoid low down load?


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Interesting question!
I suspect this is an age old adage based on a number of factors from pre-injection days.
The lower the revs, then the lower the frequency and the larger the amplitude will be of any vibration....which could potentially be harmful to engine and car.
In days of old, both fuelling and timing were less precise and pre-ignition was more likely at high load/low rpm.
As others have pointed out, machine tolerances were very different years ago so there is now much less bedding in to be done.

Most of the racing engines I have used are run for only a few minutes to 'run in' before being subject to the gentle care of a race driver;)

All engines developed by the VW group have to go through a number of torture tests. One is: new engine, cold start, full wide open throttle at full load for 100 hours!
I saw at Audi's engine plant an A8 Quattro on an external dyno doing a zero maintainace run (with auto fuel fill up!) simulated autpbahn. It was up to 180K kilometres without a single top-up of anything other than fuel!

I think there is little you can do to modern cars that will cause them grief. My 120k mile C180k turned out to be an ex Avis car, so I'm sure that had a 'gentle' start to it's life:dk:
Cars will 'loosen up' with age, but I think a small amount of mechanical sympathy in the cars first few weeks is still a good move;)
 
I think you are probably about right, there seems to be little knowledge of cars actually needing run in nowadays so its definitely a bit more of a thing of the past.

I will for sure be giving it some mechanical sympathy and a decent run in period. Theres a possibility im going to need to keep it for around 8 years so want to do what I can to keep it good!


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Thanks for opinions and advice.

Out of curiosity why does everyone say to avoid low down load?


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I alluded to it earlier.
The forces in the bearings trying to squeeze out the oil film are of the order of many thousands of pounds. Hydrodynamic lubrication that keeps the oil film intact and prevents metal to metal contact relies on rotational speed to function. The result is that the oil film thickness varies with speed and will be thinner at low revs. When the engine is heavily loaded at low revs that increases the forces in the bearings at the very time when the oil film is at it's thinnest.
 

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