Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - From down under

Would like to know at start up, do I have to keep the engine running at idle for a while before moving? if so, how long.

On stopping do I need to keep the engine running for a while before turning off? How long.

I have heard from others that this is required. As a first time user of Turbo Diesel Engine cars I seek advice.

I have recently bought an Audi A6 TDI Quattro & Mini R60 Turbo Diesel Countryman and would like to know the correct procedure so that I don't mess up the cars.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - craig-pd130

From a cold start-up, just put your seatbelt on and drive. No need to worry about it. A diesel will take forever to warm up if you just leave it idling, so drive away.

When switching off, the only time you really need to let the motor idle is if you've been cruising at high speed for a while, and (for example) pull into a service station quickly ... in other words, if you go from 80+mph to a dead stop in 30 seconds. In these situations, just let the motor idle for a minute. It helps dissipate the heat from the turbo.

In most other circumstances, after a fast drive you'll be driving at low speed through urban areas / towns, which also dissipates heat, so here it's not necessary to wait the minute before switching off.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - unthrottled

Well put.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - BenG

Is it worth idling for 30s or so on start-up to let oil circulate around the turbo bearings?

The turbo kicks in at such low revs in a modern turbodiesel that it's not really possible to drive 'off-boost' for the first mile or so...

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - Peter.N.

I wouldn't think so. I certainly don't, immediately the oil light goes out you have pressure to the turbo so unless you are going to take off like a lunatic it shouldn't be a problem

I am convinced that most turbo problems on modern cars are due to the ridiculously long oil change intervals, you rarely had trouble with turbo's when the oil was changed at 6000 miles.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - mickyh7

Surely at a steady 80 mph on the Motorway,the turbo wouldn't be boosting ?

If so, one would never get decent mpg ?

The turbo is only there to force extra fuel into the engine when one needs more performance,at least that's what I believed !

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - unthrottled

The turbo is only there to force extra fuel into the engine when one needs more performance,at least that's what I believed !

No. Turbos force more air into the engine. In a diesel, this always improves thermal efficiency.

In petrols, air flow is directly coupled to fuel flow and petrols usually perform poorly on boost.

At a steady 80 mph, a typical 2 litre diesel will be producing a modest amount of boost -probably 5 psi or so. This still provides a useful leaning effect. VG turbos can start producing boost at less than 20% of rated output.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - mickyh7

The turbo is only there to force extra fuel into the engine when one needs more performance,at least that's what I believed !

No. Turbos force more air into the engine. In a diesel, this always improves thermal efficiency.

In petrols, air flow is directly coupled to fuel flow and petrols usually perform poorly on boost.

At a steady 80 mph, a typical 2 litre diesel will be producing a modest amount of boost -probably 5 psi or so. This still provides a useful leaning effect. VG turbos can start producing boost at less than 20% of rated output.

Well I've learnt something there ! I've been wrong for years !

Never too old too learn eh ?

Regards - Mick.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - Peter.N.

I would concur, that's why a turbo diesel is more economical than a non turbo because most of the time its running on a leaner mixture.

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - From down under

Thanks to all for your valuable tips and advice.

As a first time diesel car user, I really needed this.

Its only over the past few years here in Australia, diesel engined cars have become popular.

After a daily 15 km run each way in heavy traffic, which takes me a minumum of 45 min and upto 70 min to do this daily trip to work (which will give you an idea of how bad the traffic is here in Sydney) I ensure that the engine remains on for about a minute before I turn it off. After a steady 30 min run at about 80-90 km per hr on the motorway, I keep the engine running for 90 to 120 seconds before turning off.

At start, I just leave it on for about 30 seconds, which I may discontinue based on advice received. I will just take off.

cheers

Audi A6 TDI & Mini R60 Turbo Diesel Countryman - Engine start and stop procedure for Diesel engines - unthrottled

If it is taking upwards of an hour to do 10 miles (15k), then I doubt that your turbo sees much heat anyway since you're going to be spednding much of your time idling. Even your motorway driving is pretty gentle; Turbo cool down is something to be aware of, but it mainly applies to petrols. A diesel is basically a huge air pump on overrun so as you slow down the turbo cools itself pretty quickly.

 

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