Turbo diesel cars

goldspanners

harveybobbles wrote: »

The cooling down thing only really appies to Turbo petrol models.

Make sure with yer Passat that you do yer timing belt a bit earlier than stated.

nope, it applies to all turbos, the whole point in letting it idle for a bit before turning off is to allow the turbo to stop turning before you switch the engine off,becasue when you switch the engine off you loose the oil feed to the turbo bearings. so unless the turbo doesnt have an oil feed then thats the only time it wont apply. regardless of fuel type.

vaio

goldspanners wrote: »

nope, it applies to all turbos, the whole point in letting it idle for a bit before turning off is to allow the turbo to stop turning before you switch the engine off, because when you switch the engine off you loose the oil feed to the turbo bearings. so unless the turbo doesn’t have an oil feed then that’s the only time it wont apply. regardless of fuel type.

All turbos have an oil feed, they run at stupid speeds (up to 100,000 rpm) and the bearings are very close tolerance and wouldn’t survive without a good oil feed.

It’s more to do with heat soak, when the engine is running the oil takes heat away from the turbo, if you stop it after a hard run the oil left in the bearings cooks and the resulting gritty carbon bits damage the bearings on next start-up.

It’s less of a problem with synthetic oils (higher temp range) and less of a problem with diesels as exhaust temperatures are lower than petrol engines.

A standard turbo petrol could well have a turbo glowing red hot after a hard run although, as someone else said, a few miles of gentle driving before switch off should avoid any problems, although sometimes (if pulling into services on a motorway, more so on autobahn) I would still let it idle for a few minutes before turning it off

k18dan

harveybobbles wrote: »

As for the importance of checking oil... Though I do believe it should be part of the driving test...

It is now

BenL

£700 for a turbo replacing on a 1.4 TDCI Fiesta - 53 Reg

AdrianHi

vaio wrote: »

All turbos have an oil feed, they run at stupid speeds (up to 100,000 rpm) and the bearings are very close tolerance and wouldn’t survive without a good oil feed.

It’s more to do with heat soak, when the engine is running the oil takes heat away from the turbo, if you stop it after a hard run the oil left in the bearings cooks and the resulting gritty carbon bits damage the bearings on next start-up.

It’s less of a problem with synthetic oils (higher temp range) and less of a problem with diesels as exhaust temperatures are lower than petrol engines.

A standard turbo petrol could well have a turbo glowing red hot after a hard run although, as someone else said, a few miles of gentle driving before switch off should avoid any problems, although sometimes (if pulling into services on a motorway, more so on autobahn) I would still let it idle for a few minutes before turning it off

One of the subjects I've read up on in recent years and this is the answer.
Probably a good idea to be gentle in the last minuters of driving.

AdrianHi

Andyf33 wrote: »

this thread has got me worried now.

I have a vw passat estate 1.9tdi (130) which has done 100k miles in 4 years. i do check and top up oil as necessary but oil only ever gets changed at a service which is approx every 20k miles.

Car does 60 mile to work and occaisional 300-400 mile trips and ive never done the cooling after a long run mentioned above

am i heading for trouble?

Your using a turbo diesel the way it's meant to be used, open road driving.
It's predominent short trips around town where the risk increases.

AdrianHi

RE: BMW turbo diesels.
There was a build period 2002-2004 where there was a bad crank case breather design (could block) which lead to an measurable increase in turbo failures in the 2.0d engines.
2.0d and 3.0d (includes 525d, 530d, 535d) had a weakness in the inlet manifold with "swirl flaps" which could break free and get ingested into the engine damaging cyclinder and all components down stream. Nasty.
There are horror stories around for most manufacturers diesel engines, even the Japanese makes.

vaio

Andyf33 wrote: »

this thread has got me worried now.

I have a vw passat estate 1.9tdi (130) which has done 100k miles in 4 years. I do check and top up oil as necessary but oil only ever gets changed at a service which is approx every 20k miles.

Car does 60 mile to work and occasional 300-400 mile trips and i've never done the cooling after a long run mentioned above

am I heading for trouble?

Doing the oil every 10k would add maybe £50 a year to your costs, might be cheap insurance not to mention peace of mind

Dave101t

every diesel ive ever seen has been a tdi or ctdi, i thought they were all turbos

ZootHornRollo

they pretty much are these days.

did anyone see the program on BBC4 about sales reps and the cars they drive?

it was made some time in the eighties when having an 'i' on the back of your car was a sign of status!

there was one guy who was given a gutless Rover Meastro D (not Turbo) as his company motor... he was most embarrassed at getting passed by HGV's! very funny indeed. Shame for the bloke tho... he was gutted!