Buying a turbo diesel

[Olorin]

Hi guys,

Just want to know, when buying a turbo diesel, is the turbo the only thing that really needs to be replaced every few years ? Are there any other components that diesels tend to need over and above normal aspirated ?

I remember when I went for my test drive, the 320d took off. It felt like I was in a super car in comparison to my 320i. The only thing which put me off slightly was the gearbox. It felt clunky while changing. Not smooth. Perhaps it was just the car I was in.

All the talk about a tractor sound and I couldn't hear any while I was in the car. Perhaps outside the car, but inside I couldn't hear anything that lead me to believe that there was a tractor sound.

I'm asking these questions because I've heard from many people that turbo diesels don't last nearly as long as normally aspirated engines, all things being equal and the turbo's are the first to go. Are the turbo's expensive to replace ?

I'm thinking of changing to a diesel in my next car hence the questions. Finally, is the resale value a lot worse in a diesel, assuming everything is functional correctly ?

Help on this would be appreciated.

 

[P1000]

Swirl flaps can destroy your engine. Injectors cost R2k5-R5k and can fail. What gearbox is it, auto? What year car, some had more trouble than others.

Diesel resale seems to be going for a dip.

 

[netercol]

I'm asking these questions because I've heard from many people that turbo diesels don't last nearly as long as normally aspirated engines, all things being equal and the turbo's are the first to go.

its a common misconception that turbo diesel engines are weak, in fact they are built to withstand 17:1 minimum compression ratio's and compression ignition, so in fact they are prolly twice as strong as the average petrol engine. i know a e46 320d that travels between messina and pta 2-3 times a week, and last time i saw it , had 900k on the engine. obviously several turbo's and various other components replaced, but the short block still going strong..

like p1000 said, turbo's and injectors prolly the weakest links..

 

[Olorin]

Well if I start with a E90 2005 320d. I just would like to get an idea of what kind of components would need to be replaced, beyond that of a naturally aspirated car. The turbos need to be replaced every few years, have no idea if its extremely expensive or manageable. Then the fuel injectors, but do these things go after a few years or can they fail without notice ?

P1000 mentioned that the swirl flaps can destroy the engine. Have no idea what those are or if they can be taken off or what one does to prevent failure with those. Before I took delivery of my car I was contemplating getting the 320d but I was put off because people told me that the engine wouldn't last as long and that failures are far more common with turbo diesels vs normally aspirated, all things being equal.

 

[moranor@axis]

dude did you not just get your car?

swirl flaps = metal things that fall off and go into your engine = bad
there is a retrofit you can do to fix this problem as far as i know on the e46 not sure if they fixed this problem with the e90

i wont ever get a diesel for only two reasons:
when you put you foot flat the smoke
and they dont sound good at low revs (even if i cant hear it in the car others do) before the turbo starts to whine

other than that they awesome

 

[Olorin]

Yes, I've got my car, but that won't stop me from wanting better things. So basically you are saying that the diesel is not awesome as you have more negative points than positive. : ) You mention smoke. How bad could it be ?

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Another thing. Is it true that with a turbo diesel you need to idle for a minute before turning off ? And idling for a minute before take off ? That would be a little annoying, if it were true.

 

[moranor@axis]

i just could not live with those two points

letting it idle before turning it off i think has to do with letting the turbo cool down...
i would imagine that if you were not gunning it before you stop it should be ok to just turn it off

the same with starting you should really let the turbo warm up before you start driving...

im not sure how much difference it makes but its probably worth doing...

 

[P1000]

Only if you want your turbo to last...

 

[netercol]

So basically you are saying that the diesel is not awesome as you have more negative points than positive.

dont know about that eh, ask those that have them, they all love them...

 

[Olorin]

I think one of the contributing factors towards my decision in not getting the diesel is that diesel fuel in this country is apparently very poor quality and according to many people is one of the reasons why the engines don't last as long. Is there any truth in this ? Is diesel fuel terrible in S.A ? What kind of impact would it have on our engines ?

 

[P1000]

I think one of the contributing factors towards my decision in not getting the diesel is that diesel fuel in this country is apparently very poor quality and according to many people is one of the reasons why the engines don't last as long. Is there any truth in this ? Is diesel fuel terrible in S.A ? What kind of impact would it have on our engines ?

Diesel engines last much longer than petrol, due to lower RPM mostly. Only thing that kills them is swirl flaps. Turbos blow (pun intended), and injectors fail (these may be affected by fuel).

 

[Olorin]

Are the turbo's expensive to replace ? Obviously this is all assuming the motor plan has fallen away. I'm talking specifically E90's here.

 

[P1000]

For the part only it would be around R9k (at the garrett importers), labour can be anything. Bmw will ask ~20k for the part.

 

[BMW M]

I've had a 2003 330d, the best Diesel you can buy in my humble opinion... until I bought my 2007 320d, this car is a pleasure to drive, fuel consumption is outstandind (12.8 - 17.9km/lt). Sounds like a diesel yes, but I will take on a e46 325i any day and will trump it 9/10 times.

You can see from my signature that all my cars had 'highish' mileage, and the only one that ever gave me 'serious' problems and left me stranded was the e46 325i when the gearbox packed up (R15000 to repair). I know the e46 320d's had issues up until around 2002/2003 hence I bought the 330d and stayed clear of any potential problems. But as far as what my research have shown, by the time the e90's came along turbo failure due to swirl flap failure was virtually nill.

A diesel is like any other car, if you look after it, it will return the favour. I've given mine stick on the highways many a time, when driven hard, I let her idle for a few sec's just to wind the turbo down. Mine is still under motorplan, and its something I insist on they check everytime she goes in for a service - which they do, seeing as I have a very good relationship with my Dealership. You get addicted to the torque from the diesels, you would have to buy a bigger petrol engine for the same torque output. Haviing a diesel purring along at 4200rpm @ 230km/h is something to experience... imp:

Just my 2c worth.

 

[netercol]

I think one of the contributing factors towards my decision in not getting the diesel is that diesel fuel in this country is apparently very poor quality and according to many people is one of the reasons why the engines don't last as long. Is there any truth in this ? Is diesel fuel terrible in S.A ? What kind of impact would it have on our engines ?

another myth, bmw and other manufacturers would never sell their sophisticated diesel engines here under motorplan if they thought the fuel quality will give them big repair bills..

 

[moranor@axis]

I took on an e90 320d the other day and whiped it silly but i do envy the torque thats why i feel the need for boost

 

[Olorin]

How could your 323i beat a 320d ? Isn't that technically impossible ? Well I suppose if you cheated....

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From what some have told me, a 320d has a similar pull low in the rev range compared to a 330i. Is that true ? I also know that the torque curve is very lob-sided, favoring low down and then dying out up top. But it's not like most people drive at 200 km per hour. For me, I like to accelerate in the 60-100 range and occasionally hit 160 km, but I've never ventured north of that figure.

 

[///MOS1TED]

Wanna try my DIESEL instead

:wave:

 

[P1000]

At the reef, the turbo does give quite an advantage...

 

[///MOS1TED]

So you saying a the coast , the NAs will be at a better advantage to the Turbos.

As far as I know all cars NA and Turbo both gain power at the coast.