2013 C4 1.6Hdi 115 H.p. 6 Speed Manual Exclusive

[mikeparkins]

Hi All,

        Just read about leaving the diesel engine ticking over so that turbo can slow down before turning off the ignition. I am new to Citroens and turbos but I have not read anywhere in the manuals that came with the car about doing this. Does that also mean letting the turbo run up to speed before driving off?

Sorry if I sound ignorant but I have only being driving for 50 years and in my defence ,like I noted above, I am new to diesels and turbos.

Must also mention that so far my Wife and I are very pleased with our C4, so comfortable and quiet when cruising and returning about 52mpg overall but only done couple of thousand miles so far so sure that will increase with time.

[Johndouglas]

 I have only being driving for 50 years

Hello Mike & welcome to the forum.   We must have started driving at about the same time!!

 

Yes - it's been known for many years that any turbo driven engine should be allowed to tick over for a short while before switching off.   The reason being that when the turbo is at full power, it's spinning at around 130,000 revs per minute.   When it comes off boost, it carries on spinning for some time.   If you quickly cut the engine, the turbo still spins but without any oil pressure in the bearings - hence rapid wear.   Likewise it's kinder to allow the oil pressure to build before the engine starts spinning the turbo.   However the turbo doesn't start work until the engine reaches 1500+ revs. so all that's needed here is a slowish build up of speed.

 

To prolong the life of your engine it's most important that the oil changes are carried out at or before the appointed times.   The 1.6Hdi seems to be particularly prone to turbo failure if oil changes are neglected.

[paul.h]

In our C5 handbook, under the section on starting it has:

 

Advice

Vehicles equipped with a turbo:

Turbo equipped engines MUST be allowed to return to idle for several seconds before switching off the ignition. Failure to do so could cause serious damage to the turbo unit.

Flicking the throttle pedal as the ignition is turned off can lead to severe damage to the turbo unit.

 

For the several seconds I would allow about 30. We have a C4 2011 1.6 hdi 110 bhp and we are pleased with it. Its about 32k miles now, returns average about the 52 mpg you mention but on motorway runs Warrington to Hull/Lincoln gives about 67 mpg unless into a headwind which could knock it back 10 mpg. This is at normal motorway 70 mph speeds.

[mikeparkins]

Thanks to the replies about the turbo run down and will follow the advice, although as I previously mentioned I have not read anywhere in the manuals about this. I will also pass it on to my Son who  drives a Honda diesel turbo and as he has not mentioned this to me probably doesn't know either. As the saying goes, never to old to learn.

[Playfairltd]

The turbos on 1.6 hdi are known for failure, so it is very advisable to allow the engine to run down and also to keep on top of the maintenance.

 

Hope this helps