Turbo Reliability - A ticking timebomb?
Discussion
The_Open_Road said:
It seems that most new cars these days (petrol as well as diesel) have turbocharged engines.
How reliable are turbocharged engines?
Are we sitting on a ticking reliability timebomb of lots of turbo failures a few years from now?
Only if the oil is like treacle. If the oil is kept reasonably clean and at the correct level then they're fine. Old contaminated oil is a quick way to kill them, especially on diesels.How reliable are turbocharged engines?
Are we sitting on a ticking reliability timebomb of lots of turbo failures a few years from now?
I run a highly-modified Fiat Coupe turbo, running around 450bhp - its now a weekend toy, but it used to be a daily driver. My last turbo lasted for 150,000 miles, which included everything from the daily commute (100-mile round trip) to trackdays and airfield speed events - it certainly didn't have an easy life.
Modern turbos (especially roller-bearing units, rather than journal-bearing) will last for ages as long as the oil is good (and plentiful)
Modern turbos (especially roller-bearing units, rather than journal-bearing) will last for ages as long as the oil is good (and plentiful)
The_Open_Road said:
Are we sitting on a ticking reliability timebomb of lots of turbo failures a few years from now?
Turbos have been widely used since the 90's and they are relatively cheap to reconditionYou ought to look at the complexity of the wiring on cars from around 2005, direct injection, modern automatic gearboxes or Ford Ecoboost engines if you want something to worry about.
I've had two petrol and four diesel turbos with between 100,000 and 160,000 miles, all on original turbos (according to their service histories) and all still going strong.
A VW tech mate services a PD130 engined Golf on 310k, and still on its original turbo.
I'm sure you could kill one in 50k if you tried, but modern tolerances and engine oils are remarkably effective.
A VW tech mate services a PD130 engined Golf on 310k, and still on its original turbo.
I'm sure you could kill one in 50k if you tried, but modern tolerances and engine oils are remarkably effective.
Turbos themselves are fine nowadays as most if not all are water cooled, plus modern synthetic oils dont turn to burnt black crud when they are introduced to a turbos heat, especially when the engine is turned off.
The main issues on older turbo cars are really down to the boost pipes, vac pipes, diverter valves, pressure sensors getting old, plus anything else thats been roasted.
The main issues on older turbo cars are really down to the boost pipes, vac pipes, diverter valves, pressure sensors getting old, plus anything else thats been roasted.
I understand the OP's concerns, I am on my first turbo car and to start of with I wondered the same things, is it something else to worry about etc.. I soon came to the conclusion that a cambelt or clutch is much more likely to piss on your chips. Basically do what you reasonably can to maintain your car and it "should" be fairly reliable. Sadly it doesn't always work this way.
CaptainMorgan said:
I had an Octavia vRS at 180k on the original turbo, no issue. It's still going now, someone I know owns it. I do think that more reasonable oil changes are sensible on a turbo'd car though, 2 years/20k is too long imo.
Fine as an opinion, but where is their evidence of long-life oil being..well, not long life?I have a 54 plate B5.5 passat. 1.9tdi bought at 70k miles and now has 182k. Serviced every 10k, still on original dampers, clutch, battery, turbo, engine and box. The only things replaced apart from suspension bushes and joints ( which it eats) is the alternator and both front calipers. It does a broad mix of motorway, A and B roads and lanes. Uses about 1/2 a litre of oil between changes now. Its not the most inspiring car but it wont do the decent thing and die or throw a big enough bill to scrap it and it does what I need it to do .
Garrett turbocharger on the XC90 in the Euro 3 D5 engine (no DPF) had its original turbocharger up to 170k miles when we sold it. Was beginning to have actuator issues but that was due to excessive carbon buildup from too much city driving (2k miles in the city). Very impressive considering it is a 2.1 tonne SUV.
X5 runs a pair of sequential Twin turbos, made by BorgWarner, and they are a bit more complicated. Did have to change a boost pack, which is essentially a multitude of pipes involved in the turbos of the car, but that was due to smelly morning starts. Doesn't do it anymore. It is on 120k miles and sounds very healthy and both turbos pull very well.
More can go wrong with sequential turbocharger setups on cars. The sequential system has some trick actuators which cause the large turbo to open up at 2000 RPM, and so there is more complex workings overall regarding boost and lubrication. That is not to say it isn't reliable, just a bit more complex to deal with in repairing but nothing that requires the dealer to sort it out.
In the X5, the smaller turbo can go as that is the one that is used most of the time, unless you drive like a lunatic and are always at 3K RPM. This is mainly down to weight, effectively 2.2 tonnes of weight is loaded up onto this one turbocharger when the car moves off. Probably isn't the case in smaller cars such as the 335d.
Parallel turbos aren't as complicated, the exhaust manifold simply splits into two and each manifold has a small turbocharger. That is all. Twin Scroll turbochargers get the best of both worlds but is only one turbo. They are very reliable units.
X5 runs a pair of sequential Twin turbos, made by BorgWarner, and they are a bit more complicated. Did have to change a boost pack, which is essentially a multitude of pipes involved in the turbos of the car, but that was due to smelly morning starts. Doesn't do it anymore. It is on 120k miles and sounds very healthy and both turbos pull very well.
More can go wrong with sequential turbocharger setups on cars. The sequential system has some trick actuators which cause the large turbo to open up at 2000 RPM, and so there is more complex workings overall regarding boost and lubrication. That is not to say it isn't reliable, just a bit more complex to deal with in repairing but nothing that requires the dealer to sort it out.
In the X5, the smaller turbo can go as that is the one that is used most of the time, unless you drive like a lunatic and are always at 3K RPM. This is mainly down to weight, effectively 2.2 tonnes of weight is loaded up onto this one turbocharger when the car moves off. Probably isn't the case in smaller cars such as the 335d.
Parallel turbos aren't as complicated, the exhaust manifold simply splits into two and each manifold has a small turbocharger. That is all. Twin Scroll turbochargers get the best of both worlds but is only one turbo. They are very reliable units.
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