I normally do the same, drive under 2500 (rpm!) for the last few minutes and then give it 60 seconds or so to idle.

The difference comes when you pull off the motorway to the services then I try and give it longer - trouble is the fan kicks in and takes about 3 minutes to go off and I usually like to wait.

I'm normally standing outside the car stretching the legs with my other half across the car park shouting "that's long enough, hurry up". I've tried telling her...

 

As t'other posts say, it's all relative. Pulling off a motorway into services, give it a couple of minutes (probably excessive, but better safe than etc). Most of the time after a blast you'll be driving slowly thru town etc, and a couple of miles of this takes the heat away quite nicely, so you can switch off more or less straight away.

I always like to let mine idle for 15 seconds or so before switching off, no matter how short the drive, just to make sure the turbo has spun down to "idle" too.

 

A bit paranoid, so always at least a min ad a half (which can be a pain if you are just switching cars around on the drive, or popping up to get petrol and have to stand at the pump for 2 minutes waiting). After a long run normally between 3 and 5 minutes, record of over 10 mins (long journey at 60 ).

 

Hi,

I've had my pride and joy for a little over a month now, and I want to make sure that I am treating her right...

As far as idling the car to let the turbo cool down after driving, how long does everyone do this for ?

Also, do I really need to do this after a drive to / from work if I keep the revs below 2500 for the last couple of minutes of the drive. Surely this time cools the turbo more effectively, as it is not providing boost, and there is actually an airflow over it / the intercooler ?

Any thought / comments appreciated. For the record, I currently let it idle for 60 seconds after a 'normal' drive, and for up to three minutes if I have really been having fun (only had to do this once so far, unfortunately!!).

Andrew.
MY99 DBM 5 door + SS backbox.

 

Say for example, you never bothered and just turned off the engine, what would happen?

Not that I do of course (nervously laughing)

 

For BillyH: if say you'd been blatting down the motorway at high boost (in 2nd gear of course) for 15 minutes, then pulled straight into a services and switched off immediately. Two things:

a) the turbo is still spinning at higher rpm than it would be if you'd let it idle. Worse, it's doing this when there's no fresh oil circulating -- which stresses the bearings

b) if you've been at high boost, the turbo, manifolds etc are red hot, literally. If you switch off before the cooling system's taken much of that heat away, the now stationary oil will start to cook in the turbo, and can turn to ash, which means no lube for a while on the next start-up, and rapid wear.

But these are worst-case scenarios: even just 1 minute idling will help negate most of these bad effects.

 

The problem, as my limited mechanical knowledge tells me, is that the turbo gets hellishly hot after a period on boost. The oil for the engine is also fed around the turbo - if the engine is turned off when the turbo is in "roasting" mode, then the oil can turn to sludge around the turbo (or evaporate or something ) which can shorten the life of turbo bearings and not be good for the oil which, after all, looks after the rest of your engine too.

Likewise, allow everything to warm through nicely before getting the turbo into play...

 

Fair enough, thanks for that...I'll tell my naughty mate

Next question:

Say for example after ******** my girlfriend, I get off without giving her a cuddle, will this have a long term detremental effect?

 

Think it depends on whether you are leasing or own it!!

Billy this applies to both the girlfriend and the car

 

well thankyou very much....so now, I gotta get home from work, wait for the poor ickle turbo to cool down (soft ****) and then have a smooch with her after I've had my fun.......Its such a selfless life, what about the pub and football? arent enough hours in a day!!!!

 

Aren't turbo-timers great?

Stef.

 

If the oil burning in the turbo was really a problem wouldn't turbo cars be fitted with a system to circulate the oil and water through the turbo after you switch off?.

PS has anybody seen their turbo glowing.One night I stopped at the end of a country lane after a good blast to investigate a rattling noise from the engine bay(loose bonnet stay).When I opened the bonnet the turbo and nearby pipework was glowing red hot COOL OR WHAT!

 

AndyMc: the sticker on the drivers door was seen to be a cheaper option by Subaru

 

Andy Mc, Chiark: my bro-in-law has just got a TT225, and that has an electric-powered secondary oil pump that runs for 3 mins after switch off to keep oil moving. With the extra weight, expense & complication, I'd go with the sticker too.

The water keeps circulating by itself by thermosiphon, so that's not an issue.