Running in a new diesel

[brackie]

There is an increasing trend towards buying diesel cars however some of the advice that is around is dangerous to say the least. Diesel cars are new to many dealer sales staff and I've heard them giving running in advice to customers that will seriously shorten the life and adversely affect the performance of the diesel cars that they are selling. This is particularly true for the new generation of hi-tech engines with modern turbochargers. It's not the fault of the sales staff...they just don't know any better.

One of the reasons that diesel engines outlast petrol engines is that the diesel combustion process is kinder to cylinder walls that that of the petrol engine process. This means that in the early life of the engine when the rings are bedding in it's easy to glaze the cylinder walls. The worst treatment that you can give your new engine is to run it at constant high revs...for example on a freeway or on long, straight, flat country roads until the rings have had a chance to bed in. Ironically, city driving is excellent for running in an engine as it gives exactly the opposite conditions...as long as the engine and particularly the oil gets up to full working temperatures for a reasonably sustained period. Running to the shops or taking the kids to the local school and then shutting down is a killer. Diesels thrive on hard work and long periods of running.

Below is an excerpt from a post on a TDI forum overseas. I don't think I've infringed copyright here but I'm sure the author (who is a very knowledgeable poster and is an experienced trade guy) wouldn't mind. I agree with everything he says or I wouldn't quote him.

Rules that apply for the life of the car
-When the engine is cold rev the engine to at least 2,500 rpms.
-When the engine is warmed up rev the engine to no less than 3,000 rpms.
The reason for this is to keep the turbo on boost, clear the VNT guide vanes and apply firm pressure to the rings for optimal sealing against blow-by gasses. The rings need the boost to seal since it’s a turbo charged engine, babying the engine is detrimental and will lead to issues with compression if done so for very long.

First 1600km
Keep rpms below 3,800. Avoid steady rpms. Frequent firm application of power is strongly recommended up to 3,800 rpm. Avoid the use of cruise control so that you naturally fluctuate the power with your foot.

1,600-8,000 km
Use the full ~5,000 rpm power range. Avoid steady rpms. Avoid the use of cruise control. Frequent application of full throttle is recommended to help seat the rings. City driving is ideal for breaking in a TDI due to frequent stops and acceleration. Once you get to 8,000 km change the oil and perform your first service per the manual

8,000-16,000 km
Use of the cruise control is ok at this point since most of the initial break in has occurred. Continue to use occasional full throttle accelerations to continue to seat the rings. You will notice the engine become slightly louder during this phase due to less friction from the engine breaking in (normal for a diesel to become louder under lighter loads). If your going on a long drive and you are using the cruise, every so often step on the peddle to accelerate up about 30 kmph then coast back down to your preset speed.

16,000-100,000km
This is when the rest of the break in occurs. The engine from the factory will check out with about 475psi of compression pressure out of the crate. It will take at least 10,000 km to reach the peak pressure of 550psi. For the most part once you get to 16,000 km your compression will be around 510psi meaning that most of the break in has occurred.

100,000-the life of the motor
The engines I have seen so far using a 5w40 oil are maintaining 550 psi of compression pressure with over 300,000 km on the odometer. The owners have followed the advice above and do not have any oil consumption issues. This also means that with the higher pressure the engine is more efficient returning optimal fuel economy and reduced smoke output.

***Disclaimer*** Altough I agree with what is said above I take no responsibility for any detrimental consequences of following this advice. You may disagree with all or part of the above and if you do please keep this discussion going. That's what forums are for

[Golf Loon]

Thats interesting reading. That would give good longevity to the life of a car. The danger surely of buying a secondhand diesel is that you dont know whether the original owner ran it in correctly.
Makes me wish I could afford a new one

[SOHC]

I just learnt more good information thanks Brackie, however I am wondering does the motor run-in procedure also apply on gasoline engines, and do they only apply on the new technology engines? Like the TDI, FSI, or any fuel injected engines.

Cheers
Carlson

[vinderliker]

Great article Brackie, will definately taking the advice on board when i buy my Touareg(this weeks $2 lottery winnings . I wished!!!!!!!!!!!

[brackie]

Great article Brackie, will definately taking the advice on board when i buy my Touareg(this weeks $2 lottery winnings . I wished!!!!!!!!!!!

No, mate...both of us can't win it!

Does this procedure apply to petrol engines? Basically, "Yes". The critical parts are bedding in the rings and looking after the turbo, so if the petrol engine has rings then it applies. Good compression is paramount to the performance of any diesel...especially regarding its ability to start first pop...Modern turbos (from what I have read) seem a lot more user-friendly than the old T2s etc, but they need running in too.
It seems that if you live in the city and don't do a lot of constant-speed freeway driving you'll have no trouble running in correctly.
But the thing to avoid (not just in the running in period but for the life of the car) is short runs where the engine oil doesn't get hot. It's easy to think that you've achieved full operating temperature when the water temp gauge tell you, but hot oil comes much later.

Loon.. You're dead right. Buying any used car is a gamble as you don't know if or how it was run in. And this applies especially to modern turbodiesels. I'd buy a high km country car every time if I knew it had been properly run in.

[gldgti]

i'd be willing to wager my $2 on this applying to the older idi non turbo's as well... its shorter odds too

its definately interesting stuff, and i think, unknowingly, i've driven my car well for the engine as long as i've had it.... its a very strange thing indeed, and almost counter intuitive, but i'm beginning to truely believe that diesels actually do prefer to be working hard.

an interesting little story may now be appropriate...

my mate recently sold his diesel cressida. it was a '90 with the turbo 2L-T that surfs and diesel cressidas have, and a very nice car overall.

unlike vw diesels, this engine is of the large block design, for its 2.4 litres its a large engine and being toyota, has a short rev range compared with vw engines (redlining at 4300) however i know these things are still good reliable engines. (note, the car was an auto)

my friend had the car for about 2 years, before that it was owned for about 8 years by his grandfather, out in the country - before that it lived in japan, and was imported on v'low km's. it was babied around its whole life, always driven slowly.

after my mate got it, he drove it undoubtedly harder than his grandfather, but he's not a wreckless person..so it wasnt flogged. my mate did believe in not reving it hard though...

anyway about 18months after getting the car, main bearings failed and its was dead. its whole life the car had been babied around and just done easy criusing, and i'd reckon it was certainly not run in properly.

needless to say, theres an inferiority to asian manufactured diesels (cars too ) but on 220k i dont think it should have had main bearing failure.

my car is driven hard most of the time. i accellerate around town hard, as i can, its still economical, and the cars no powerhouse. i use the full rev range... i get close to the dots on the speedo often enough. to keep it economical when not driving really hard but still scooting around, i use lots of throttle through the low/middle of the rev range most of the time, and then give it WOT for hard acceleration.

with larger exhaust and non restrictive intake, my car seems happy to rev out all the time.... my oil consumption is still ok, it uses a little, but the cars on 315k and it had new rings at 260k to "fix" a blowby issue.

what do you guys reckon?

[Golf Loon]

I`m very suspicios of low kms Jap import engines. If someone has to get rid of an engine at 40,00kms, as if they look after it or change the oil. i reckon they flog em hard then ship em off to Australai.

[brackie]

These diesels are not the best. The 2.8 has an even worse reputation. At the risk of discussing Toyotas on a VW forum, they usually fail in the ring/piston/bore area.....just where poor running in usually takes it's toll. To have main bearings fail in any modern 5-bearing-crankshaft motor (except perhaps Subaru...personal experience ) is most unusual. I would suspect oil starvation. Simplistically, running in is all about seating the rings.

[coastie]

It's amazing the complete contradiction I got from VW recently. I bought a T5 multivan about 2 weeks ago and the mechanic said not to take it much over 2000 rpm for the first 1000 km. The VW logbook says not to exceed 75% of top speed for the first 1000km.

I agree with the restricted use of the cruise control for the run in period but it is so smooth to use and incredibly accurate that it is hard not to want to use it.

The advice above is certainly interesting to read but I wonder if a car manufacturer spends millions developing an engine and issue guidelines on how to run it in and then use it, why would their information be so wrong.

My personal belief is to not have constant running at a set speed but to vary it so that the cylinder does not end up with a lip created during the initial wear.

Aren't the engine bench run for a set period prior to installation into the vehicle?

I can't say that I'm driving this one any different to any other diesel I have owned. The warm up info is vital to get the car hot and to drive it immediately rather than let it idle to get warm.

I'll have to wait and see how it all turns out.

[Jettinabout]

I worked on Cape York ten years back and had a new landcruiser as a work vehicle. It was brand new and I had started to baby it a bit and had to take it in for a service. The diesel mech took me aside and had a quick and very informative chat so to speak, it went like this...

Don't baby this thing and I will show you why. See those two cruisers over there, one old and beaten up one and one six month old, clean, immaculare one. The old one has been driven by everyone on site and flogged .. we don't touch anything on it because it just doesn't ever have anything go wrong with it.

The other one is owned by one of the managers and is only ever driven by him. It is in here every other day getting fixed. The reason for that is because it is babied.

So I am telling you now to flog the crap out of that thing and you will never have anything go wrong with it....I did from then on .. he was right. Its still going strong with very few problems.