Blown turbos question(s)

[TooT]

How does a turbo blow? what exactly happens inside the thing for it to pack in? and why do they blow is it something to do with too much pressure?

Is there any way of looking after a turbo? Apart idleing before and after a journey.

The reason is ive blown another turbo on my work van, 1st on lasted 95k before it gave in, but ive just killed the one on my 07 Sprinter which is only 8 days and 1400 miles old
Needless to say my boss is pissed.

[mbell666]

which is only 8 days and 1400 miles old
Needless to say my boss is pissed.

I don't think you broke it, thats what you call manufacturing fault!

95K isn't bad for a turbo, how low they last varies between cars and engines. Drove a skoda octavia 1.9tdi with gone turbo, that lasted about 110K, was a taxi thou so had lots of right foot and was running about 20 hours a day!

(This may be complete rubbish but i am sure niz or someone will come and correct me )

I think the shaft between the turbines runs on oil and the shaft spins very very very fast. So if you have crap oil, never change it, don't have any or the oils seals go badly then the shaft will not rotate correctly , overheats and kills the turbo, or the turbines can hit the housing.

Generally, to be nice to my turbo I:
- I let the car idle for a few seconds before turning off, to let the turbo spin down as much as possible before remove the oil supply.
- Keep the revs low when cold, try to avoid spinning the turbo up to much on thick cold oil.
- Change the oil frequently to avoid crap getting into the turbo oil feed.

[mjb]

- I let the car idle for a few seconds before turning off, to let the turbo spin down as much as possible before remove the oil supply.

As I understand it, it's not so much the spinning as it is getting rid of the heat. As you said, the turbo spins extremely fast (up to 150,000rpm!) when in use, so it gets ludicrously hot which is why oil is pumped to it instead of coolant. When you kill the engine, the oil stops pumping which means the whole turbo assembly is going to get ludicrously hot (as opposed to some bits ludicrously hot and some just very hot) and that change in temperature and associated cooling afterwards can cause things to seize.

Best thing is to drive the last few miles without causing the turbo to spool up, and leave it idling for a minute or two before killing the engine.

[Eric]

-
Best thing is to drive the last few miles without causing the turbo to spool up, and leave it idling for a minute or two before killing the engine.

One or the other should be ok you don't have to do both and usually 30 seconds or so the let the turbo cool at idle will do it rather than sitting there for ages.
You can get turbo timers for Jap cars and others I guess and they run the turbo for a time depending on how it's been running so you can get out of the car and leave the engine running that will turn off when it's cooled.
As far as I know legally in the UK they are a grey area because you aren't allowed to leave a car running unattended.

[diesel-dog]

Should I be expecting my turbo to call it a day before too long?
194,000 D8 TD, worked as a taxi, professionally driven

[mbell666]

generally the turbo's on pugs are quite good and last pretty well.

It wouldn't surprise me if it did fail at some point in the not to distant future, but there again it could last for years!

[niz406]

generally the turbo's on pugs are quite good and last pretty well.

Are they?? Damn.... I'm on my 5th Turbo... lol - But this is a petrol ! !

Ok so mine is a mixture of being sold something that was never fitted and my right foot! ! !

Typically its irregular oil changes, and poor driving conditions.... thrash cold and no idle cool down time.. On the Pug's the tub's are low pressure so its not down to the pressure, most problems can be attributed to Oil and Coking... Seals typically fail as a result of coking on these low pressure units.

What happens depends on the failure....

1) Foreign Object - Compressor Wheel / Turbine Wheel can shatter and the debris can take out the cover and/or core
2) Coking - Bearings weld to the core and the shaft making it impossible to rotate
3) Seals blow - Exhaust and Compressor housings fill with oil and result in blue smoke
4) Oil contamination - Scoring to the shaft and bearings
5) Oil Starvation - blockage in feed pipe can cause bearings to run dry and 'burn in' the core, results in blue coloring of the shaft in places and eats into the core.
6) Thrust bearing / Plate wear due to excessive boost pressure's can result in 'in/out' shaft play
6) Worn bearings due to excessive boost pressure's and oil conditions can result in 'typical left/right' shaft play

Anything else you would like to know

[TooT]

that sounds like a voice of experience

The first time i had one go was senario 3 above. Clouds and clouds of blue smoke, quite spectacular it was

Dont know what happened last week. Van comes back on monday. Merc had to ship a new turbo from Germany. None in the uk because its so new, I must be the first

[niz406]

that sounds like a voice of experience

My First one died because of Number 2 wasn't my fault honest the turbo had already done 90k miles !
My Second one died because it didn't have a 360 degree thrust bearing fitted as it was suppose to and I ran higer boost and it caused 4 / 6 / 6 ?? Ops that'll be a 7 then!
My Third One had 360 bearings and the Turbine std oil seal failed.... smoke every where
My Fourth one don't know yet until its off the car... but Seals have gone!

My new one........ well that won't go not whilst I own it lol

I change oil / filter every 3k miles so it will never be oil related lol

[diesel-dog]

Hell, now the paranoia has set in!!

How easy or costly is replacement? Brand new or scrappy?

I want to prepare myself for the probable inevitibility of a big smokey death!!

Just because you're paranoid, doesn't mean they're not after you!

[jameslxdt]

diesel turbos have a very easy life as they run quite low boost, the 406 1.9 uses about 14psi, and also they operate at a MUCH lower temperature than the petrol counterparts, you will know when it fails as you will get plumes of blue and black smoke, literally LOADS, and a massive loss of power, my old diesel 406 was on 182,000 miles and the turbo was fine, ive still got it if yours ever dies, so dont be so paranoid

[diesel-dog]

Thanks for putting my mind at rest, thanks for the offer too, I will give you a shout if I start to fill Cornwall with smoke

[Welly]

My collegue has got a Twin Turbo Mitsubishi and had developed his own safety system for the Turbo's.

Upon engine shut down an electric oil pump sends oil (filtered from the sump through a separate 5-10 micron filter) directly to the turbo's and through the oil drains back to the sump. It's all adjustable and he has it running for 10 mins on a count-down timer.

The oil pump is also used for pre-start oil priming.

When the engine is running this oil system is by-passed using non-return valves and the turbo's are fed from the engine's oil pump.

The water side had a separate radiator and pressure cap for the turbo's and an electric water pump, the water never goes above 50 deg C typically, and if it does the immersion sensor switches 2 small fans fitted to the radiator (basically a big oil cooler).

I think these Turbo's should last well

[niz406]

My collegue has got a Twin Turbo Mitsubishi and had developed his own safety system for the Turbo's.

Upon engine shut down an electric oil pump sends oil (filtered from the sump through a separate 5-10 micron filter) directly to the turbo's and through the oil drains back to the sump. It's all adjustable and he has it running for 10 mins on a count-down timer.

The oil pump is also used for pre-start oil priming.

When the engine is running this oil system is by-passed using non-return valves and the turbo's are fed from the engine's oil pump.

The water side had a separate radiator and pressure cap for the turbo's and an electric water pump, the water never goes above 50 deg C typically, and if it does the immersion sensor switches 2 small fans fitted to the radiator (basically a big oil cooler).

I think these Turbo's should last well

Now thats a bit overkill he must thrash the pants off it lol

I did consider fitting an oil cooler / filter circuit to the 406 turbo, because of the turbo's location... but then decided against it, as it really was a bit OTT for stock levels lol!

[jameslxdt]

i agree with niz on this, an electric oil pump could never deliver oil at a higher enough pressure to have much effect, at idle your typical oil pressure will be arround maybe 2 bar, if there was a pump that could deliver a fluid as dense as oil at 2 bar then i would like to see it, your far better off with a turbo timer in reality