TDI Turbo cool down.. necessary or not..

[benuk]

Ever since I have owned my PD130 turbo I have always let it idle for 30s - 1m, and 2-3 minutes after a long or hard drive. Is this necessary, I am interested in what others of PD130 / PD150 turbos do? I can't imagine your average TDI driver doing this.. All it says in the manual (buried away) is something like 'let the engine idle for around 2 minutes after the engine has been under heavy load for a long period of time'

If it was important would they not install a turbo timer / cooler? Like the petrol turbos have?

 

[Martin_FR]

I do it aswell

I was sent on an industrial diesel engine course and was told when you shut off your engine your turbo is still spinning at 1000's of rpm but theres no fresh oil going to it as the pump isnt running. This applies to cars aswell. It can only do good. Dont think TDi turbos get as hot as petrols though

 

[ChrisGTL]

I do it aswell

I was sent on an industrial diesel engine course and was told when you shut off your engine your turbo is still spinning at 1000's of rpm but theres no fresh oil going to it as the pump isnt running. This applies to cars aswell. It can only do good. Dont think TDi turbos get as hot as petrols though

I make sure I drive nice and steady towards the end of my journey, and let it idle for 10-30seconds.

If i'm really working the turbo hard I let it idle for 2-3mins before shutting down. The oil stops pumping when the engine is switch off, therefor the remaining oil thats on the turbo bearings gets very very hot and the oil film is too thin to really protect, plus the oil cant carry the heat away so it just cooks itself to death.

 

[Martin_FR]

I usually just creep in my street and the street before it without hard acceleration. Obviously sit at 20 -30 but I dont nail it

 

[Neo]

The road leading to my house has lots of speedbumps, so the last 2 minutes of my journey home is done in second gear at idle -ish and I reckon this must help. I also try to let it idle for a bit on other trips. I have thought about a turbo-timer, but as you said, if it was THAT crucial I think there would be one fitted as standard.

I think all turbos need to be warmed and cooled properly to reduce the risk of thermal shock cracking the turbine and compressor blades.

 

[Martin_FR]

The road leading to my house has lots of speedbumps, so the last 2 minutes of my journey home is done in second gear at idle -ish and I reckon this must help. I also try to let it idle for a bit on other trips. I have thought about a turbo-timer, but as you said, if it was THAT crucial I think there would be one fitted as standard.

I think all turbos need to be warmed and cooled properly to reduce the risk of thermal shock cracking the turbine and compressor blades.

I dont think I know of any cars that come standard with a turbo timer? Im sure there are though, just dont know which ones.

When im starting any of our tractors, I crank it over first with the stop button in so that it wont start. Just gets oil up to the turbo before the turbo actually starts spinning. Some of our tractors lay unused for a week at a time or more

 

[kriso]

I don't think any would come standard as it's illegal to leave your car unattended with the engine running.

 

[Ibiza 130 tdi]

Dont think TDi turbos get as hot as petrols though

Really? I dont know but I'd have thought they got hotter boosting higher pressures? Maybe?

To be honest, it's not necessary to do it but as said - it can't do bad and will help to keep your turbo happy. If you're going to run hybrid turbo's then it's more necessary. I always get in mine and let it tickover for a bit before driving off, then do the same when i stop - let it tick over for a while then turn it off.

There's an old boy in work gets in his car, puts it in gear with his foot on the clutch, starts the car and literally lifts the clutch and drives off straight away!! There cant be any oil gets round the engine - but hey ho, his car.

 

[Martin_FR]

Really? I dont know but I'd have thought they got hotter boosting higher pressures? Maybe?

To be honest, it's not necessary to do it but as said - it can't do bad and will help to keep your turbo happy. If you're going to run hybrid turbo's then it's more necessary. I always get in mine and let it tickover for a bit before driving off, then do the same when i stop - let it tick over for a while then turn it off.

There's an old boy in work gets in his car, puts it in gear with his foot on the clutch, starts the car and literally lifts the clutch and drives off straight away!! There cant be any oil gets round the engine - but hey ho, his car.

Iv seen petrol turbos glowing hot before, never seen it on a diesel though. thats the only reason I though. Maybe cause petrol engines rev higher?

 

[Neo]

When im starting any of our tractors, I crank it over first with the stop button in so that it wont start. Just gets oil up to the turbo before the turbo actually starts spinning. Some of our tractors lay unused for a week at a time or more

Yeah, I think the priming/warming up must be just as important - the oil will be thicker when cold and also will have fallen to the sump, so it will have a harder time getting through the oilways for the turbo bearings until it reaches the correct viscosity. maybe?

 

[Ibiza 130 tdi]

Iv seen petrol turbos glowing hot before, never seen it on a diesel though. thats the only reason I though. Maybe cause petrol engines rev higher?

Yeh I know what you mean. I've seen one catch the manifold on fire it's got that hot! I suppose you could be right! Like I say I dont know - just guessing.

 

[Martin_FR]

Yeah, I think the priming/warming up must be just as important - the oil will be thicker when cold and also will have fallen to the sump, so it will have a harder time getting through the oilways for the turbo bearings until it reaches the correct viscosity. maybe?

Plus on industrial engine, the turbos usually at the top or pretty high so its already done 1000's of revolutions by the time the oils reached it. But then, big industrial engines have auxilliary lube oil pumps and the engine wont start until the oil pressures reached a set point

Anyway, back to talking about TDi's and not industrial engines

 

[kriso]

Petrol burns at much higher temps than diesel, so the exhaust gasses and turbos get much hotter.

 

[PH1L NI]

Never.

 

[sssstew]

correct, petrol turbos get lot hotter and glow when driven hard, the exhaust gas in a TDI is much lower as TDIs are more thermally efficient (ie less engergy is wasted as heat going out the exhaust) so their turbos dont get so hot.

So generally its good practice to do as ChrisGTL says above and allow a little but its not as necessary as with a petrol turbo engine.

 

[Ultra_Joel88]

Yes I do - can't really hurt can it?

 

[Husbandofstinky]

Virtually never. The Leon is used mainly for work and sometimes to other friends and family homes. Work and home are in built up areas (30mph zones - but realistically 20mph). To me these are the 'cool down' times before shutting the machine off.

 

[Craig Senior]

The only time I ever really let mine cool down is if I stop at the services on the motorway. I'll let it tick over for a minute or two before switching off.

The rest of the time it's usually through built up areas so I never bother.

 

[beezanick]

Tend to drive nice and easy for the last few miles of a journey to let it cool down, or if Ive been giving it the beans, leave it idle for a few minutes.

I always wait for the oil to come up to temperature before driving on boost though.

 

[Davidsr]

I usually let it idle for about 10-20 seconds when I've got in from work, but I have about 2 miles at 30mph before I get home so gives it an easier drive after being on mway.