This is probably a really stoopid post

ive heard the phrase " the turbo blew/went in my car"

I presume this just means that the the turbo part of the car has totally broken or essentially " blown up " : ) and the car cannot be driven until turbo part is replaced ?

I presume this can happen in both Turbo Diesels AND Turbo Petrols ?

Or does it mainly just affect Diesel cars with Turbo ?

What causes a turbo to blow ?

Lots of questions, I know

As I said, probably a stoopid post.................................

It is (or at least was) more common on petrol turbo cars, although a recent number of dervs have had issues with turbo's doing this too.

If it's properly blown, then there is a good chance of damage to the engine, the exhaust and other components.

In the dervs, the turbos tend to stick more than self destruct, although they can let go too.

any more comments ?

Like lots of car problems, if it isn't happening to you don't worry about it. Our 2.0 TDI has done getting on for 143,000 miles and has had no turbo problems.

We've also got a Mazda Bongo MPV Jap import and if you went by all the forum discussions on coolant problems, you'd never drive it! We've had ours for over two years and it's fifteen years old and hasn't had any mechanical problems.

You can't drive a car with a blown turbo, they require oil from the engine to lubricate and cool them. If the turbo has failed, chances are an oil seal has gone too, this will allow oil to leak from the bearing assembly into either the hot exhaust turbine or the intake compressor. Either way this isn't good for the engine at all. As soon as a turbo goes the engine should be shut down immediately.

Turbocharger reliability is a lottery to an extent. Some cars can be thrashed from cold all their life and the blower lasts over 150k. Other cars can be handled with the greatest of care and go pop after 30,000 miles or less. Pot luck in some cases.

As a whole, turbos are much more reliable these days and you shouldn't worry about something that might never happen. People mostly seek out car forums when there is a problem with their car, this skews things a little in terms of perceived reliability.

The biggest killers of a turbo are poor oil change intervals, thrashing from cold and turning off the engine immediately after a hard drive. The turbo and oil need adequate time to warm up and cool down properly. Failure to observe these rules will undoubtedly shorten its lifespan.

As already mentioned, newer Variable Nozzle (or Geometry) Turbos (VNT or VGT) can suffer from jamming up due to soot from the diesel engine, this can cause the turbo to behave incorrectly as it relies on the intake guide vanes to be in position 'x' at exactly the right time. The vanes are used to control boost pressure and turbo speed, a jammed VNT can cause overboost and/or overspeed. The former will usually result in an engine safe mode to protect itself, the latter can result in the turbo destroying itself due to excess centrifugal force acting on the turbine and compressor. The lack of wastegate means all boost pressure control is governed by the vanes.

A turbocharger will spin up to 150,000 rpm under full load. Some are even higher than this. I think the turbo on the new 1.0 litre Ford engine spins over 200,000rpm.

Quite often, people hear a turbo 'whine' or whistle when under load, this is usually normal when a turbo is operating correctly, only occasionally is this a sign of impending doom.

It helps to understand the principles of a turbocharger. Some more reading here if interested:

http://auto.howstuff...s.com/turbo.htm

http://en.wikipedia....ki/Turbocharger

http://www.turbobyga...bygarrett/basic

http://www.holset.co...ger%20Works.php

^^^^^dstev2000, thanks for the excellent reply

^^^^^dstev2000, thanks for the excellent reply

+1, great explanation dstev2000.

So based on the answers, sounds like if one maintains their car properly, the turbo " should " be ok ; )

I think certain small allowances have to be made for turbocharged vehicles with regards to warm up, cool down etc. along with regular and correct oil changes. These things will help prolong the life of the turbo.

A turbo shaft spins at nearly 300,000 rpm, works in temperatures of over 1,000 degrees c, varies speed by 250,000 rpm in under a second and cooled by only a few drops of oil......

As dstev2000 says above oil quality is THE most important thing dictating a turbos life span...but people forget a bad driver does too.

A blow off valve, wastgate and variable vanes are all there to control turbo boost...but also to prevent turbo stall and overspeeding.

If you overtorque a turbo shaft (thinner in diameter than a biro) then the shaft tries to twist in its axis, this allows the compressor wheel to impact the housing it runs inside.

The bearing in the majority of stock turbos is essentially two piston rings around the shaft that sit in the centre gallery of the housing, its not designed to take load.

Overtorquing of the turbo happens when you drop say 6 to 2, dump the clutch and put the engine rpm high in the red.....the turbo reacts to this aggressive action and tries to twist in the housing.......when you over rev an engine or do the same action as described above on downchange you can overspeed the turbo (seen turbo rpm of nearly 500,000 rpm), the oil in the turbo at this point can "burn" off the shaft and cause heat spots etc.

The turbo has to be thought of as a diamond ring on a miners hand, very delicate PRECISE pieces of engineering working in the harshest conditions in your engine bay....treat them badly at your peril!

police cars blow the turbos a lot because the vehicle is driven hard and then switched off straight after with no time to 'cool' I understand that condensation forms in the turbo which kills it (I'm not too techy as u can tell..) sensible driving or letting the cool tick over for 1-2 minutes after fast driving should be enough- most manuals recommend such.

also, the vehicles in question were Vectra's, the Octy's don't have the same problem...

Some great techical advice so thanks to those who have taken the time to post.

My simple tip is to check your oil level regularly and top up - As explained above the oil coats the turbo and if your oil is low...

got new turbo on octy 1.9 diesel after old one failed. New oil added to flush out any contaminate. Regular oil service due in about 2k km. can I take it I can now postpone oil service due to new oil being put in with the replacement turbo?

My tip on a diesel is to thrash it now and again to keep everything clear and prevent the vanes clogging with carbon and diesel deposits. This is why you see turbos on low mileage cars go, because they have been driven so gently they just gum up causing uneven centrifugal force on the bearings.

Also use proper diesel with cleaning agents and not supermarket fuel.

The difference in performance between a turbo and a non-turbo small diesel engines is night and day.

Those of us who've driven the old naturally aspirated diesel cars will never forget the heart-stopping moments when you've tried to 'zip' into a spare space in the traffic, like say joining at a roundabout, floored the damned thing and nothing, absolutley nothing, happens!

Of course, a turbo diesel is going to be less reliable than exactly the same engine without one. That's only natural - there's yet one more thing to go wrong.

BUT without turbos, I believe that small diesel cars just wouldn't sell.

Given that modem oil has a consistent viscosity over a range of temperatures, why should you bit thrash the engine when cold? At the end is the production line, every car plant I have been in they get hammered as part of the last inspection. I could understand it from a thermal expansion point of view, but modern engines are machined sufficiently well to not be affected by this any more