RPM during break-in period

Doesn't hurt to let it rev reasonably freely, the worst thing you can do is sit it one speed for long periods of time, vary it a bit.
No need to baby it too much.

This is my own opinion and should not be used by someone with more intelligence.
Just flog it.
In other word words do not sit on a constant speed. rev it up and down along as it does not increase engine temperature.
I have done this to a lot of company cars at have done around 200,000 ks in each.
If it does not work than it is the next owners problem.

honky

Have u read the manual?

Dreamerman

My purely personal unscientific advice is that you keep the revs low. To me, that is rarely exceed 2,500, and almost never reach 3,000. My intuitive reason for this is that wear is due to the speed of the piston in the cylinder - keep the speed down and reduce wear. Also ensure that you run the engine up to operating temp before putting it under any sort of load.

Having said that, my mate is an engine fanatic who rebuilds antique Listers and such like. When I drove his V8 Toyota the way I drive my car he seemed very edgy, and asked me to rev it a bit more!

I can also understand that putting a lot of torque through at low revs must stress the piston rings, but there has to be a happy medium. For me that is about 2,500 rpm.

My diesel has done 206,000km and still feels like new.

Bob

In the "olden days", strict instructions were given for running in, with low speeds and low engine RPM's for the first 500 miles (800kms) and easy driving with varied speeds up to 1000 miles (1600kms).

"Running in" periods and warnings and instructions for new vehicles, have gone the way of the dodo, due to vastly improved machining and manufacturing tolerances, better materials, and no more need for initially "tight fit" components, as in the old days.

Run your vehicle at normal speeds, normal acceleration, and include a reasonable amount of high speed running in the first 2000kms and you won't have any problems.
I have bought many diesel vehicles new and done many, many kms with each of them, and never had any problems.
The only thing you need to watch is the engine temperature if you buy a vehicle new in the middle of Summer, and need to do long runs at highway speeds initially.

I've had new Landcruisers sitting on high speeds (open-road Territory speeds and higher) for hours, with little more than 1000kms on the clock and they never gave any problems throughout their many years of life.

Breaking in a diesel

It is a good question Dreamerman, and one that is seldom asked these days. Yoy will get many different answers from do nothing to the very specific. So I have attached a link which gives one perspective of what to do and what not to do. This article is from USA so is referring to probably larger diesel engines than yours but you can make your own judgements about the principles this article exposes.
Link (if above click-on does not work):
http://www.thedieselstop.com/contents/getitems.php3?Breaking%20in%20a%20Diesel%20Engine

Another aspect that I personally do after buying a new vehicle is change the oil 1/2 way to the first schedule service...i.e. if its 10,000km service change all oils at 5000km. It would not hurt to change the diff oils as well. If you plan to keep the vehicle for 10 years its worth doing it right in my opinion.
Cheers

Good morning Dreamer
There you are , by reading all that input, you just drive it to the conditions. I agree with the oil change , but that is only if you want. I had a few company cars and you treat the new one like the one you just got rid of .

Have you read the operating manual?

Drive the beast normally - don't flog it. Drive it the way you are going to drive it later. Avoid max RPM for a while, but at the same time definitely avoid slugging at low RPM's as well. The recommended procedure for bedding in new piston rings used to be to warm the engine thoroughly and then take it out onto the road and from lowish speed, accelerate at max throttle in top gear up to 50 mph, then back to 15 and back up to 50 mph. Repeat this 10 times and the rings were bedded in.

I put new rings in a Sigma many years ago and without testing it at all, drove it at night on a 120 km trip. On the way out, I went up a steep hill (full throttle in 4th gear) and there was a car following me. In the mirror and with his headlights, I could see smoke coming from the rear of the car. On the way back, the same thing happened (a different car following) but this time there was no smoke. After that, it never touched a drop of oil between changes.

I bought a new Pajero in 2000 and because of illness, I was unable to drive it for several months. My wife drove it and would not exceed 80 km/h for the first 1000 km. The rings never bedded in and it used oil (about 1L per 1000 km) for the rest of the time I had it. The Magna we had at the same time never touched a drop of oil. Just before i traded it in, I had a catastrophe (my doing) and had to rebuild the engine to makel it saleable. The original honing marks were still visible in the bores and it had 235000 km on it at the time. I bedded in the rings as before, but never got to see how the oil consumption measuerd up.

Our 2 new cars have been run in according to the above rules, and neither of them use any oil between changes. My new pajero has done a fair bit of harder work towing but it runs very sweetly.

So my recommendation is to thoroughly warm the engine (to get the oil circulating properly) and to take it out and drive it normally for the first 500 to 1000 km. During this time, make sure that it gets an occasional burst of full throttle. If possible, towards teh end of the breaking in period, really load it up. Unless you are going to race the engine, it is not necessary to rev the hell out of it - just drive it the way you are going to drive it when it is run in.

Dreamerman
The only part of a modern engine that requires any form of 'run in' process is the piston rings, and the ring manufacturers suggest a full throttle acceleration from around 60kph to around 100 kph in a direct gear followed by a closed throttle deceleration back to 60 kph, and repeat this procedure for 10 consecutive cycles without the use of the brakes (does require using a relatively quiet appropriate section of highway). After this procedure the engine is considered to be fully 'run in' .

This is the process that I have carried out with every engine that I have rebuilt over the past 40 odd years and never had any issues relating to engine life.

Also the best engines that I have been involved with have all had a long highway drive very early in their life over some hilly/undulating roads where they have had plenty of variation in the load and speed that they were subject to.

The MOST important thing with ANY engine is never to apply too much load at excessively low engine speeds (lugging the engine), Revs, up to their designed maximum, will not harm them and it is better to have a few more revs rather than not enough revs.

The biggest killer of engines is heat, whether that be excessive heat or a lack of heat when subject to heavy load, it is also advisable to get the heat into the engine as quickly as possible after a cold start up, and that is by driving the vehicle with moderate loading until normal temperature has been attained. DO NOT start a cold engine and allow to idle for lengthy periods to warm it up, as a cold engine operating at low speed suffers from a lack of lubrication.

Hope this helps
Regards
Athol
Retired Motor Mechanic

Read you service book that came with it! That's will tell you what you need to do! You'll get fifty different answers here and they all won't be correct, Michael

Just get in it and drive the bastard, hook up what ever ya tow even, just drive the damn thing.

Some people seem to get a sort of 3rd person empathetic personality to a piece of suck squeeze bang blow reciprocating machinery.

Why would you be revving it to 3000rom or even 3500rpm in 1st gear ever in it's whole life?
1st is a crawler gear and used for starting the mass on the vehicle moving and then selecting higher higher speed/ lower ratio gearing as you speed up. ie, once the vehicle mass is moving so should the gear stick. Is drag racing a necessity?

Just because the manufacturer has additional numbers to print on a tacho which are far more than the engine will safely rev to, isn't a reason to try and use them.

Just drive it normally without high revs and high loads or low revs under load, so it has a chance to microscopically run in/wear in the high spots of machined surfaces.
You can rev the crap out of anything and surprisingly many last for a while but not as long as a "cared for" engine.

Took delivery of a brand new HR Holden (company car of course) on 23rd Dec 1966. Next day 3 mates and I headed to Surfers for Christmas. Once past Shepparton with 134 miles on the clock we reckoned it was run in and from there we sat on 100 Mph for most of the rest of the way. Had that vehicle for over 200,000 miles and it was one of the best cars I have ever had. I use to give the Valiants a bit curry I can tell you.

The worst treatment of any engine but particularly diesels is to idle them for long periods whether warm or cold. Pussy foot around with it and the rings will not bed in properly. Don't flog the gonads out of it with high revs but a good load applied at mid range RPM will do it the world of good.
Consider that when the fuel mixture goes bang on top of the piston the rings get pushed to the bottom of their grooves and gas gets between the piston and the back of the ring. This forces the ring against the cylinder wall thus helping to seal the expanding hot gasses from escaping into the sump. It also helps the rings with the bed in process.

Cheers
Pop

SO THE RESULTS ARE...
1. Change oil 1/2 way to first recommended oil change....smart move.
2. Do not lug the engine...possibly glaze the bore and use more oil later.
3. Stay at about mid range revs..3000-3500 rpm.
4. Do not sit on a constant rev range for hundreds of k,s....vary the revs.
5. Do not allow to sit idling for long periods of time.
6. Modern diesels, like most modern motors, are virtually run in at the factory.
7. Don't be a fool and rev the bejesus out of it wherever you go...especially on start up or when cold.
8.Regardless of what the manual says...change oil every 5000 klms....oils cheap...engines aint

good luck

As was said earlier, everthing about how motors are machined and built has changed.

Accuracy of maching has moved forward considerably...materials have moved forward too.

back when we where running pushrod motors with either rigid or hydraulic lifters there was a whole lot of stuff that needed bedding in in the top end of the motor.....that was the point of the first low rev period of the run in..to allow the valve train to bed in.

the next phase was to allow the bottom end and the rings to bed in.

Of course after the run in peroid the head bolts where re-torqued because the gasket had squashed down a bit...and the valve clearances where re adjusted.

as has been said all this is a thing of the past....in the modern twin overhead cam motors, the valve train is far simpler and more direct and many ovehead cam vehicles never have their valve clearances adjusted ever.
The head gaskets don't need re-torquing and modern assembly is better than the balancing and blueprinting that would have occured in race motors of 25 yeras ago.

Just the chaenge in valve seats alone is a quantum leap...back in the day the valves where ground and seat was cut directly in the head and some poor schmuck had to sit there for a couple of hours lapping the valves with a lapping stick and compound....and run in was definitely required.

these days the valve seats are hardened material and are very accurately "multi-facet machined"..some will tell you no lapping is required at all or at least very llttle and more or less no run in.
Hell I know a bloke in the next street that has a multi facet vale cutter in his garrage...who knows what the funkiness the big manufacturers have.

Besides...if the manufacturer realy thaught the engine needed some sort of restriction in the run in peroid...they would programe that into the ECU.

You would be wise not to flog the thing espacielly when cold , but babying it is equally unwise.

cheers

Thanks all for your views. I tried to keep the rpm down today but it is just too hard. My ute is brand new with 11kms on the odometer when I picked it up 2 days ago. I just drove it carefully on the slow lane and did rev up to about 3000rpm a few times when required.