Turbo Reliability - A ticking timebomb?
Discussion
Keep the oil changes frequent (so consider maybe not going to the full drain interval the manufacturer states depending on your driving situation e.g. town driving vs motorway driving; hours count just as much as miles). Give the car a moment of idling to ensure the oil has circulated when you fire it up (as in, get in, engine on, then do your seatbelt kind of time...not sitting idling for 5 minutes etc etc), and then just go half throttle / half revs for 5 minutes or so. I saw somewhere something about modern multigrade oils and their viscocity with temeprature. Even at 40 deg.C they are closing in on their optimum operating temperature viscosity (see https://wiki.anton-paar.com/en/engine-oil/). So it's really just the cold cold mornigns you need to be a bit more careful.
Wife has a 2005 120D. We keep the oil changes frequent (6000-8000 mile intervals instead of the 15,000 mile stated by BMW) and so far, at 122,000 miles, we are doing ok n the turbo (no oil consumption etc).
Wife has a 2005 120D. We keep the oil changes frequent (6000-8000 mile intervals instead of the 15,000 mile stated by BMW) and so far, at 122,000 miles, we are doing ok n the turbo (no oil consumption etc).
havoc said:
Wife has a Mk7 Golf GTi - quick google came up with this thread and quote for a Golf-R...bigger turbo but hardly low-volume...
https://www.vwroc.com/forums/topic/24893-golf-r-tu...
"Picked up the car with its new turbo and ancillary parts last night. Total parts came to £1874.55."
Even a used GTi part on eBay is up for £479.
So whilst I don't doubt you ref. an old TDi lump, for anything even mildly* interesting (and this IS PH, after all), you're definitely talking 4-figures as I said...
* Golf GTi is hardly the last word in PH'ness.
Again I disagree. To change a turbo on a Mk7 GTI is around 3 hours labour and £480 plus 3 hours labour is not 4 figures. https://www.vwroc.com/forums/topic/24893-golf-r-tu...
"Picked up the car with its new turbo and ancillary parts last night. Total parts came to £1874.55."
Even a used GTi part on eBay is up for £479.
So whilst I don't doubt you ref. an old TDi lump, for anything even mildly* interesting (and this IS PH, after all), you're definitely talking 4-figures as I said...
* Golf GTi is hardly the last word in PH'ness.
I've been in the modification scene for a long time and the costs are not that much for turbos etc.
For £1800 you can get a new hybrid unit to get well over 400hp for example.
The quoted price is for a new unit from VW with VW labour rates
xjay1337 said:
havoc said:
Even a used GTi part on eBay is up for £479.
Again I disagree. To change a turbo on a Mk7 GTI is around 3 hours labour and £480 plus 3 hours labour is not 4 figures. Moreover, there's a lot of people out there that don't WANT to go modding a car (as you seem happy to do), and DO want to fit OEM parts (on the basis that they're (a) designed for the car and (b) probably better built than the EuroCarParts special).
So for your average joe, changing the turbo on their hot-hatch IS a 4-figure bill...
My 26 year old Japanese turbocharged car is still on it's original turbo (Around 90,000 miles).
The engine was pulled apart last year to replace a load of weeping seals and gaskets. The turbo didn't need doing and is in great working order, only with the tiniest amount of play in the compressor wheel. It definitely wasn't enough to warrant any work on it.
Regular oil changes are key.
The engine was pulled apart last year to replace a load of weeping seals and gaskets. The turbo didn't need doing and is in great working order, only with the tiniest amount of play in the compressor wheel. It definitely wasn't enough to warrant any work on it.
Regular oil changes are key.
havoc said:
So for your average joe, changing the turbo on their hot-hatch IS a 4-figure bill...
That's a hot hatch though. And a stubborn PH joe who insists on OEM bits, not an average joe who doesn't care. I mean, if you want to get very specific to prove a point, then it's probably a 5-figure bill on a Ferrari F40. And 6-figures on a Veyron...But really, without picking on specific cars and weird owners, across a typical cross-section of modern vehicles, it's no worse than a clutch. On a Focus it'll be a few hundred quid, maybe 700. On a hot hatch, it'll be 4 figures. A turbo should last longer than a clutch, but I don't see similar concern about clutch replacement bills making cars unbuyable or uneconomic to service? So why pick on the turbo?
I think the balance of opinion in this thread is that turbos will last just fine. But even if you disagree with that (fair enough), then surely it's no worse than a clutch change? Or, if you want to argue that friction devices are consumable, turbos are not, then fine, is a turbo failure more common than an alternator failure? Or a head gasket? Or a water pump? I can think of cars where those items are just as expensive as a turbo.
Generally speaking, it'll be 100k miles plus before it needs doing, it'll cost 3 figures on a family hatchback, or 4 figures on a performance hatch... It's really not a big deal considering the lifetime of the part.
No average joe in an average hatch is going to insist that their 120k mile £5k commuter VAG has the turbo replaced with a genuine warranted part at a main dealer. It's disproportionate. The local garage will do it, with a pattern part or a recon unit with a 3 month warranty, and that'll be plenty good enough for another 80k miles, by which time 99.9% of vehicles are scrap.
Tartan - all very fair points...have learned stuff from this thread. I was just getting miffed at jag who took my '2nd hand part' cost and used that to justify HIS argument ref. replacement cost...seemed rather disingenuous.
I've had to replace clutches on my last 3 cars...in two cases <£1k, in the third >£2k. Something you expect on a 2nd-hand car as it closes on 100k. Turbos seem rather more variable in longevity, and at least as susceptible to prior-owner treatment...which makes it more of a risk, but that's just IMHO.
Although I would disagree on one point - I suspect most performance-car owners WON'T go for pattern-parts unless the car, as you say, is a £5k machine not worth spending the extra on. They'll go for OEM or for an upgrade (which will most of the time be more £).
I've had to replace clutches on my last 3 cars...in two cases <£1k, in the third >£2k. Something you expect on a 2nd-hand car as it closes on 100k. Turbos seem rather more variable in longevity, and at least as susceptible to prior-owner treatment...which makes it more of a risk, but that's just IMHO.
Although I would disagree on one point - I suspect most performance-car owners WON'T go for pattern-parts unless the car, as you say, is a £5k machine not worth spending the extra on. They'll go for OEM or for an upgrade (which will most of the time be more £).
havoc said:
xjay1337 said:
havoc said:
Even a used GTi part on eBay is up for £479.
Again I disagree. To change a turbo on a Mk7 GTI is around 3 hours labour and £480 plus 3 hours labour is not 4 figures. Moreover, there's a lot of people out there that don't WANT to go modding a car (as you seem happy to do), and DO want to fit OEM parts (on the basis that they're (a) designed for the car and (b) probably better built than the EuroCarParts special).
So for your average joe, changing the turbo on their hot-hatch IS a 4-figure bill...
If you insist on using NEW GENUINE parts then again keep an eye out.. ihi turbo as fitted to Mk6 GTI engine is around £750 if you know where to buy them but there is often no need when there are plenty of quality re manufactured places, that aren't Euro Car Parts, that specialise in making decent re manufactured/rebuilt turbos.
After all if you clean the housing, fit new genuine shaft, wheels, seals and bearings, is it not a new turbo anyway.......
I have nothing to gain by lying but implying that turbos are incredibly expensive things is not quite the case if you know where to look :-)
TartanPaint said:
No average joe in an average hatch is going to insist that their 120k mile £5k commuter VAG has the turbo replaced with a genuine warranted part at a main dealer. It's disproportionate. The local garage will do it, with a pattern part or a recon unit with a 3 month warranty, and that'll be plenty good enough for another 80k miles, by which time 99.9% of vehicles are scrap.
Exactly that.Most boggo turbos in the diesel or petrol modern cars, 320d , 2.0tfsietc need no special traetment besides oil changes. Some turbos have oil and coolant feeds so will last longer, you don't need a turbo timer unless you are running some modified monster, it is pretty pointless on moderm cars, the the hum drum ones are built to last.
xjay1337 said:
If you insist on using NEW GENUINE parts then again keep an eye out.. ihi turbo as fitted to Mk6 GTI engine is around £750 if you know where to buy them but there is often no need when there are plenty of quality re manufactured places, that aren't Euro Car Parts, that specialise in making decent re manufactured/rebuilt turbos.
This exactly. The turbo will be made by a third party - IHI, Borg Warner, Garrett, Mitsubishi etc - so there's no need to go to the car's main dealer to get the exact same part as can be supplied by others for a much reduced cost if you really do insist on having a brand new turbo supplied. Unless you've abused the car then you'd have to be incredibly unlucky to be needing a new turbo before 100k miles, and how many people still take their car to the main dealer for anything at that sort of mileage?xjay1337 said:
After all if you clean the housing, fit new genuine shaft, wheels, seals and bearings, is it not a new turbo anyway......
Precisely. The housing shouldn't wear at all in normal use so there's no difference between a new housing and the used one. Clean the housing and replace the innards and you have, to all intents and purposes, a brand new turbo.havoc said:
Although I would disagree on one point - I suspect most performance-car owners WON'T go for pattern-parts unless the car, as you say, is a £5k machine not worth spending the extra on. They'll go for OEM or for an upgrade (which will most of the time be more £).
There's nothing wrong with pattern parts from the likes of Melett. They're a well respected company that make high quality components.Thesprucegoose said:
Most boggo turbos in the diesel or petrol modern cars, 320d , 2.0tfsietc need no special traetment besides oil changes. Some turbos have oil and coolant feeds so will last longer, you don't need a turbo timer unless you are running some modified monster, it is pretty pointless on moderm cars, the the hum drum ones are built to last.
While a watercooled turbo will generally manage heat a bit better, you still should be mindful of running it hard and then shutting the engine off shortly after - this causes the oil to "burn" onto the bearings etc, which shortens the lift of the turbo considerably. Just be sensible for the last 5 minutes of your drive and it'll be fine, and if for some reason that's not an option and you've just subjected it to a high load, just let it idle for a minute before shutting off, it'll be fine.Johnnytheboy said:
What are people's thoughts on the combination of turbos and stop-start technology?
I imagine that like everything else relating to stop/start the system would have been durability tested though x1000s of cycles in various conditions, and will include lock-outs that will disable the stop/start system if the engine is in a condition that would make it unwise to suddenly shut it down (high exhaust tempertures, or x-seconds since boost was measured at >y bar or something).But more generally I don't think it'd be a problem. Stop-start, by its nature, is used most in urban driving when exhaust temperatures and boost are generally low and you're certainly not going to be heat-soaking everything to the point of the turbine housing or manifolds glowing cheery cherry red. Neither are you going to have the system firing the engine up and going straight into high load/high boost situations. You're going to be slowing/coasting to a stop in traffic and pulling gently away from junctions or traffic lights.
Even in the case when you're pulling off a motorway into a services after 2 hours of high speed driving, it's not as if you're doing a Le Mans pit-stop. You coast down the slip road, faff around looking for a parking space, get into the parking space etc. Plenty of time for the turbo to slow and cool down before the stop/start comes into play.
Johnnytheboy said:
What are people's thoughts on the combination of turbos and stop-start technology?
On my car 335d. On the rare occasions I don’t switch the stop/start off (e.g. slow traffic in a town or city), the stop/start does not always operate. It indicates that is not operating by a stop/start wording in the instrument cluster with a cross through it. In those situations it computes to disable stop/start because conditions are not met; among those being (according to handbook):Outside temperature too low
High outside temperature and air con on
Interior not heated or cooled to desired temperature
Engine not yet at operating temperature
Sharp steering angle or steering operation
After reversing
Condensation when Air con is on
Vehicle battery is heavily discharged
At high altitudes
Bonnet is unlocked
Parking assistant is activated
Stop and go traffic (I am not clear about this)
Selector in N, M/S, or R
Use of fuel with high ethanol content (unlikely)
Some are safety related, some are related to high demands on ancillaries or to protect engine and thus including turbo.
havoc said:
So for your average joe, changing the turbo on their hot-hatch IS a 4-figure bill...
How much does the smaller turbo engine save the average joe over its lifetime versus having a larger NA engine and does that outweigh even the worst replacement costs?My car has about 300hp and at the time it was made would likely have needed a V8 of around 4 litres to provide the same kind of power across the rev range that the turbo provides. With the turbo 4 pot it averages 29mpg day to day with minimal motorway work, whereas the V8 would likely be approximately 20mpg (taking the Jag XK8 from the PH real world mpg wiki as an example). Over an expected turbo life of 150k miles, that's a saving of over £14k in fuel at today's prices.
Thesprucegoose said:
SonicShadow said:
While a watercooled turbo will generally manage heat a bit better, you still should be mindful of running it hard and then shutting the engine off shortly after - this causes the oil to "burn" onto the bearings etc, `
burn onto bearings, sounds like b
ks, thermal shock is the issue.people talk about turbos like they are running a 90's skyline, the vast majority driving 'hard' their 320d will be just fine. https://www.fuelsandlubes.com/fli-article/toyota-s...
"For gasoline engines, deposit formation begins at temperatures above 180C. Spikes to this temperature and higher can happen when the following sequence occurs: a high load engine operation followed by engine shut down after short idling. When that happens, heat from the exhaust system flows back into the turbocharger turbine, shaft, and bearing, which can lead to coking."
jagnet said:
How much does the smaller turbo engine save the average joe over its lifetime versus having a larger NA engine and does that outweigh even the worst replacement costs?
My car has about 300hp and at the time it was made would likely have needed a V8 of around 4 litres to provide the same kind of power across the rev range that the turbo provides. With the turbo 4 pot it averages 29mpg day to day with minimal motorway work, whereas the V8 would likely be approximately 20mpg (taking the Jag XK8 from the PH real world mpg wiki as an example). Over an expected turbo life of 150k miles, that's a saving of over £14k in fuel at today's prices.
OK, off topic, but to address this...My car has about 300hp and at the time it was made would likely have needed a V8 of around 4 litres to provide the same kind of power across the rev range that the turbo provides. With the turbo 4 pot it averages 29mpg day to day with minimal motorway work, whereas the V8 would likely be approximately 20mpg (taking the Jag XK8 from the PH real world mpg wiki as an example). Over an expected turbo life of 150k miles, that's a saving of over £14k in fuel at today's prices.
BMW were making very smooth and flexible +/- 270bhp n/a engines for a number of years - straight-6, 3.0 litres, >30mpg real-world - N52 started at 231bhp in +/- 2000 and ended at 268bhp in 2007 (when the DI N53 took over). As compared to a Saab with 250bhp as standard. So little real benefit vs your car then.*
(Also, XK8 is a very cute example - old-school torque converter auto, with a big, lazy, untuned V8 - hardly representative of what an n/a engine can do)
A LOT (not all) of the so-called 'economy benefits' of turbos are down to the old NEDC measurement regime (and to a lesser degree the new one - WLTC?), which favour engines that develop a lot of their torque low-down in the rev range. THAT is what's driven the change-over to turbos from n/a, to a large degree.
As an example:-
http://www.fuelly.com/car/bmw/328i/2012
This engine replaced the N53 330i in the BMW line-up (and is less powerful), yet only delivers 24-28 (US) mpg (so ~29-34 UK mpg) real-world for an average owner. N53 owners were regularly getting mid-30s mpg average. Where's the benefit from turbo-downsizing?
Moreover, you're forgetting the compromises of a turbo'd engine - throttle response and sound. Only really relevant on a performance car, granted, but a lot of people would still prefer the sharper response and nicer sound of n/a...
* I have direct experience of another comparison - JDM-spec (higher power, 236bhp) 2008 Civic Type R vs both a 2007 Mk5 Golf GTi (197bhp) and a 2017 Mk7 Golf GTi (217bhp).
Civic returns 30-32mpg combined, 33-35 on a long-run depending on cruising speed.
Mk5 returned 32-33mpg combined, 33-36mpg on a typical run (where economy was more dependent on cruising speed - my view is it was thirstier at WOT)
Mk7 is actually little different to the Mk5, despite the claims. Presumably because it's been mapped for more torque in order to game the NEDC better.
And before you claim 'torque deficit', the shorter-gearing of the Civic means that wheel-torque is virtually identical (within 10%) to the (contemporary) Mk5, albeit lower than the Mk7.
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