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Allow diesel engine to idle before switching off?

Jamie91

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2005 iCDTI Saloon
Hi,

Firstly hello :)

Last weekend I brought a 2005 Accord 2.2 CDTI Exec, and haven't looked back.

In the manual it mentions that the car should be allowed to idle for 10 seconds at the start of a journey, and allowed to idle for 10 seconds at the end of a journey in order to protect the turbo.

Is this really the case, if the car is driven slowly for the first 10 seconds and last 10 seconds of each journey (i.e. manoeuvring in and out of a parking spot?)

Thanks !
 
Got to agree no need to sit still,if driven sensibly, but not every one is sensible, i.e start and foot down hard, roar round the estate into driveway switch off, not good for turbo's. Many rapid response diesels have come to a sticky end by such treatment. The oil in the the turbo is hot the turbo is red hot and the result is a gooey mess build up preventing efficient circulation.
 
first 10 seconds is for oil pressure to build to correct pressure.
last 10 seconds is to allow the oil pump to push very hot oil oil the turbo before you turn off.

it always advisable to drive carefully until the engine has reached full opperating temp. and for the last few miles of your journey, not to drive hard and let the engine cool before you park up.
 
5-10 seconds before driving off, at least 10 mins before pushing at all but ideally 10 mins after the coolant gauge is up to temp (coolant heats up much quicker than the oil), leave it idling for 30 seconds before turning engine off.

At least that's what I do, no exceptions no matter how in a hurry I am.
 
I agree, always let the pressure build for 10 seconds, then allow the oil to heat and thin a bit before booting it. Cooling is vital, I take it easy for that last 5 mins then let it idle for a few seconds, if you have been pushing it and not taken it easy for the last part just idle longer...... Or fit a turbo timer ;-)
 
Iv been doing this since ownership of the accord. The accord gets warmed up 10min befire being driven and allowed to idle for 3min before switching off. Even during the first 5-10 min of driving keep the revs below 2k rpm. And 5-10 min before you reach your destination keep the revs below 2k rpm
 
Start the engine and I'm off. I don't hammer it until it's fully warmed up.

I let it idle for a few seconds when the journey is finished.

If I'm at a service station I will let it idle for 30 seconds before switching off.
 
It's probably just as bad to under rev during the first part of the trip, heavy loads on the bottom end with thick oil, I just keep it sensible while it warms. Have never heard of bearing failure from low rpm driving to be fair haha.
 
It's probably just as bad to under rev during the first part of the trip, heavy loads on the bottom end with thick oil, I just keep it sensible while it warms. Have never heard of bearing failure from low rpm driving to be fair haha.

True I tend to watch the live fuel consumption gauge as a good estimate of engine load.
 
I always let the car cool off for a few mins after a long journey. Agreed hot turbos can cause all sorts of problems. A correct cool down can defo increase the life of the turbo
 
5-10 seconds before driving off, at least 10 mins before pushing at all but ideally 10 mins after the coolant gauge is up to temp (coolant heats up much quicker than the oil), leave it idling for 30 seconds before turning engine off.

At least that's what I do, no exceptions no matter how in a hurry I am.

That's the same thing I did with my old Accord. 89k to 158k miles in two years with no problems :D
 
Also worth remembering diesel turbos run higher boosts and spool quicker often making positive boost when just coasting.

People differ but I allow 30 secs before switch off but I don't idle warm up as It's better to get the oil moving just drive gently.

As said earlier coolant will heat up quicker, so when the gauge hits optimal your oil still has a little to go.
 
Think it might be a good idea for oil pressure and oil temp gauges :D
 
Pretty much essential to do this, because turbos rotate at 100000 rpm +, so switching off before it can slow itself down when the engine idles, means no oil is then circulating through those still rapidly spinning bearings.
 
Iv been doing this since ownership of the accord. The accord gets warmed up 10min befire being driven and allowed to idle for 3min before switching off. Even during the first 5-10 min of driving keep the revs below 2k rpm. And 5-10 min before you reach your destination keep the revs below 2k rpm

Not good to tick over, it glazes your bores, drive immediately, but keep right foot light.
 
Not good to tick over, it glazes your bores, drive immediately, but keep right foot light.

I've heard this too. Just get in and go, but keep it gentle until engine is up to temp.
 
Not good to tick over, it glazes your bores, drive immediately, but keep right foot light.

Is it also cos again the coolant will get hot but the oil won't even start warming up until you start driving it - so you wait 10 mins, your coolant gauge says good to go but then it's another 10-15 mins after pulling away before you can drive properly!
 
Is it also cos again the coolant will get hot but the oil won't even start warming up until you start driving it - so you wait 10 mins, your coolant gauge says good to go but then it's another 10-15 mins after pulling away before you can drive properly!
SEe I got told to let it get warm so at least you know there is oil flowing to the turbo charger. . . And again to let it cool before shut off to let it stop spooling so your not depriving the turbo of oil and causing damage to the bearing.. but if the diesel gurus say it ok to drive then so be it :)
 
SEe I got told to let it get warm so at least you know there is oil flowing to the turbo charger.

But the oil pump will get (cold) oil around the turbo within 10ths of a second, it's gunning the turbo on cold oil that's the problem rather than a lack of any oil. So when you're sat there with the engine running but not going anywhere the turbo has cold oil going around it and the engine coolant is heating up - so when you pull away the dash temp gauge reads in the middle and you think it's OK to drive it harder - but in reality the oil is still cold cos you weren't driving the car for the first 10 mins, so you end up pushing it with cold oil in the turbo.

Basically my advice is; start car, drive away, drive gently for 5 mins after gauge reads normal (as above I use the MPG dial to guesstimate engine load), when you stop let the car idle for 30 seconds then turn it off.

As an aside I had a mate who used to start his diesel straight up without waiting for the heater plug light to go out - his reason was it takes a few more turns of the engine to get it started which gets the oil pumped up through the turbo before it spools up fully - rather than the engine starting straight away and running the turbo up for 1/2 a second with no oil. Seems legit.
 
I do try to do this but sometimes when ur late(like i am) its a bit hard to do...lol
I always drive carefully when first running her up until shes warm then i can give it a bit more welly if needed.
Ive always had turbo timers on my last cars but is this possible on the accord?
Is there a harness u can get fit one? Ive never seen one, if not how difficult would it be to fit
 
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