How Unreliable Are Diesel Cars?
Discussion
We all know that if you search hard enough, you will find horror stories for every car / engine / gearbox.
As a collective, how have we found owning modern diesel cars (euro 4-6)?
Do you think the benefits still outweigh the disadvantages for diesel given the amount of technology and the ever-changing legislation?
As a collective, how have we found owning modern diesel cars (euro 4-6)?
Do you think the benefits still outweigh the disadvantages for diesel given the amount of technology and the ever-changing legislation?
How did I find it with cars we've had in my household? 100% reliable as far as the diesel bits have went. That's with a '63 plate Civic 1.6 i-DTEC and a '13 plate Astra GTC 2.0 CDTi.
The Astra never missed a regen in all the time I had it. The Civic doesn't give any clues about when it is in regen but we've had it nearly eight years now. Both have proven more efficient and cheaper to run than a hybrid I had alongside the Civic.
As far as 'easy to own, easy to live with' cars go, both were great. I have more fun in my supercharged Cooper S but the tax, fuel and repair bills are obviously higher so...
The Astra never missed a regen in all the time I had it. The Civic doesn't give any clues about when it is in regen but we've had it nearly eight years now. Both have proven more efficient and cheaper to run than a hybrid I had alongside the Civic.
As far as 'easy to own, easy to live with' cars go, both were great. I have more fun in my supercharged Cooper S but the tax, fuel and repair bills are obviously higher so...
Got my first diesel 2 years ago after exclusively petrol.
It’s a 1.7crdi from Kia and now on 95k miles with partial service history.
No engine, dpf or transmission problem, really easy to live with.
It doesn’t get used for short journeys.
Averages 48mpg and that’s not hanging around with the lorries.
Euro 5.
It’s a 1.7crdi from Kia and now on 95k miles with partial service history.
No engine, dpf or transmission problem, really easy to live with.
It doesn’t get used for short journeys.
Averages 48mpg and that’s not hanging around with the lorries.
Euro 5.
Just got rid of wife's 8yr old Tiguan, EU6 with AdBlue.
She only did shopping and school run (not every day, we're grandparents) mileage in it, with a very occasional longer trip. Was on 43K when it was sold, and despite the horror stories you hear about such use, had no issues other than a random glow plug failure about a year ago, fixed under the VW "All In" cover pretty effortlessly.
It used to do its own thing on regens - could do a long trip over the weekend then go on the 3 miles school run in the morning and it would be doing a regen when we arrived. They never passive regen apparently. But never once had a dpf warning show.
I sold it because I couldn't renew the All In package anymore the VW warranty was looking expensive, and, perhaps oddly, I felt hanging on to it was temping fate - not just the diesel and AdBlue bits, but the engine has some kind of triple cooling system (does away with having an electric booster heater and it blew warm air in a few hundred yards, but you're still into the teens of miles before the engine oil temp is up to normal). The car was also DSG and 4Motion, so more stuff to go wrong.
She only did shopping and school run (not every day, we're grandparents) mileage in it, with a very occasional longer trip. Was on 43K when it was sold, and despite the horror stories you hear about such use, had no issues other than a random glow plug failure about a year ago, fixed under the VW "All In" cover pretty effortlessly.
It used to do its own thing on regens - could do a long trip over the weekend then go on the 3 miles school run in the morning and it would be doing a regen when we arrived. They never passive regen apparently. But never once had a dpf warning show.
I sold it because I couldn't renew the All In package anymore the VW warranty was looking expensive, and, perhaps oddly, I felt hanging on to it was temping fate - not just the diesel and AdBlue bits, but the engine has some kind of triple cooling system (does away with having an electric booster heater and it blew warm air in a few hundred yards, but you're still into the teens of miles before the engine oil temp is up to normal). The car was also DSG and 4Motion, so more stuff to go wrong.
Don Roque said:
...Both have proven more efficient and cheaper to run than a hybrid I had alongside the Civic.
...
Curious about this, as I have gone from a diesel to a hybrid (Prius Gen4) and find the Prius significantly cheaper to run (more mpg, cheaper fuel, lower service costs etc.) Which hybrid did you have?...
Don Roque said:
How did I find it with cars we've had in my household? 100% reliable as far as the diesel bits have went. That's with a '63 plate Civic 1.6 i-DTEC and a '13 plate Astra GTC 2.0 CDTi.
The Astra never missed a regen in all the time I had it. The Civic doesn't give any clues about when it is in regen but we've had it nearly eight years now. Both have proven more efficient and cheaper to run than a hybrid I had alongside the Civic.
As far as 'easy to own, easy to live with' cars go, both were great. I have more fun in my supercharged Cooper S but the tax, fuel and repair bills are obviously higher so...
Thats interesting. I can always tell when my car is doing a DPF regen, higher RPM, cooling fans on, feels massively underpowered and easy to stall when pulling away.The Astra never missed a regen in all the time I had it. The Civic doesn't give any clues about when it is in regen but we've had it nearly eight years now. Both have proven more efficient and cheaper to run than a hybrid I had alongside the Civic.
As far as 'easy to own, easy to live with' cars go, both were great. I have more fun in my supercharged Cooper S but the tax, fuel and repair bills are obviously higher so...
I'm currently running a VW 2.0 turbo DSG diesel (Euro 6 with AdBlue). (Having not had a diesel since 2006).
Done 15,000 miles.
It seems fuss-free from the maintenance angle. Took a while to work out how to find the AdBlue range, but now I know it's £12 every 1,500 miles. No other engine-related issues.
But the driveability is rubbish, frankly. I'd rather have a non-turbo petrol, because they behave as you'd expect.
This diesel has such inconsistent power delivery, sometimes nothing when you want some (you press the gas and count to 4) and sometimes an instant thrust that has the front wheels squealing.
Done 15,000 miles.
It seems fuss-free from the maintenance angle. Took a while to work out how to find the AdBlue range, but now I know it's £12 every 1,500 miles. No other engine-related issues.
But the driveability is rubbish, frankly. I'd rather have a non-turbo petrol, because they behave as you'd expect.
This diesel has such inconsistent power delivery, sometimes nothing when you want some (you press the gas and count to 4) and sometimes an instant thrust that has the front wheels squealing.
LJF_97 said:
Thats interesting. I can always tell when my car is doing a DPF regen, higher RPM, cooling fans on, feels massively underpowered and easy to stall when pulling away.
You could tell in the Tiguan if stopped as tickover would be 950RPM instead of 800, and stop/start didn't work (although we normally always turned that of anyway). Couldn't hear the fan unless you stopped and got out of the car. Didn't appear to be any different while driving.M4cruiser said:
Took a while to work out how to find the AdBlue range, but now I know it's £12 every 1,500 miles. No other engine-related issues.
As an aside, it always puzzled me that people made such a big deal of the RX-8’s oil consumption - £6 every 2000 miles! If you could afford the petrol, you weren’t going to break the bank on oil. Reliable.
2004 Golf 2.0 GT tdi 140, bought at 30k miles driven to 120k miles, a few bits and pieces on top of regular servicing but nothing horrendous.
2012 Skoda 1.6 tdi 105, bought at 3k miles driven to 110k miles, as above for costs but needed an Italian tune up every 3 months when the dpf light came on.
2018 Mercedes Vito, bought at 5k miles currently has 50k miles, drinks more ad blue than it should but it’s been faultless.
Also had a couple of VW Transporters and a Golf GTD as company vehicles in this time, one Transporter needed a new dpf but it was done under warranty the other Transporter and Golf were faultless. I don’t have the full details on the mileages on these.
I cover a lot of miles and make sure they get some revs every now and again the blow the rubbish out of them so probably the the perfect use case.
2004 Golf 2.0 GT tdi 140, bought at 30k miles driven to 120k miles, a few bits and pieces on top of regular servicing but nothing horrendous.
2012 Skoda 1.6 tdi 105, bought at 3k miles driven to 110k miles, as above for costs but needed an Italian tune up every 3 months when the dpf light came on.
2018 Mercedes Vito, bought at 5k miles currently has 50k miles, drinks more ad blue than it should but it’s been faultless.
Also had a couple of VW Transporters and a Golf GTD as company vehicles in this time, one Transporter needed a new dpf but it was done under warranty the other Transporter and Golf were faultless. I don’t have the full details on the mileages on these.
I cover a lot of miles and make sure they get some revs every now and again the blow the rubbish out of them so probably the the perfect use case.
The OH has an early 2005 BMW 120d which she's owned for at least 14 years, now with 100k miles on it. 100% reliable, except for a corroded reluctor ring causing the traction control to cut the engine power until it was turned off.
A close friend of mine bought a BMW 318d (F30) with 50k miles on it and ran it to 120k miles. Only issue was a new starter motor required at about 115k miles.
A close friend of mine bought a BMW 318d (F30) with 50k miles on it and ran it to 120k miles. Only issue was a new starter motor required at about 115k miles.
M4cruiser said:
I'm currently running a VW 2.0 turbo DSG diesel (Euro 6 with AdBlue). (Having not had a diesel since 2006).
Done 15,000 miles.
It seems fuss-free from the maintenance angle. Took a while to work out how to find the AdBlue range, but now I know it's £12 every 1,500 miles. No other engine-related issues.
But the driveability is rubbish, frankly. I'd rather have a non-turbo petrol, because they behave as you'd expect.
This diesel has such inconsistent power delivery, sometimes nothing when you want some (you press the gas and count to 4) and sometimes an instant thrust that has the front wheels squealing.
Which model have you got? I know the DSG / TDi combinations do vary but our DSG Tiguan never gave a moment's concern over its driveability. although it's not exactly a car you'd want to drive on the ragged edge. It was pretty effortless, really, and I liked that it felt almost locomotive-like in its torque.Done 15,000 miles.
It seems fuss-free from the maintenance angle. Took a while to work out how to find the AdBlue range, but now I know it's £12 every 1,500 miles. No other engine-related issues.
But the driveability is rubbish, frankly. I'd rather have a non-turbo petrol, because they behave as you'd expect.
This diesel has such inconsistent power delivery, sometimes nothing when you want some (you press the gas and count to 4) and sometimes an instant thrust that has the front wheels squealing.
Your AdBlue consumption sounds way higher than ours, although I suppose it depends what you're paying for it - I know it's leapt up in price. Ours used a litre every 500 miles. The dealer did want to do an update last time it went in that they were very vague about other than "it's related to the Adblue system" - I refused it, it's worked for 7yrs so messing around with it now doesn't seem smart.
I've been driving diesels since 2007. All have been serviced properly and all have done a reasonable mileage with a mixture of short and long journeys. I've never had a single problem (apart from an alternator, so not diesel related)
Cats include: Mondeo, Seat Leon, Honda Accord, VW Passat, Toyota avensis, Skoda superb, insignia, astra, ford c-max and BMW 218... I used to swap company cats a lot.
The unreliability comes from when people do too many short journeys without letting the car fully warm up. Diesel cars are meant to do higher mileages.
Cats include: Mondeo, Seat Leon, Honda Accord, VW Passat, Toyota avensis, Skoda superb, insignia, astra, ford c-max and BMW 218... I used to swap company cats a lot.
The unreliability comes from when people do too many short journeys without letting the car fully warm up. Diesel cars are meant to do higher mileages.
Worst engine experience I have had is from a 5 year old VW euro 6 2.0 tdi. Great engine apart from the issues caused by the emissions bolt ons…. Dpf can’t regen itself in winter which leads to a whole load of hassle and other problems due to oil dilution - a £10 carista dongle had to be used a couple of times a month in winter to force a regen that the engine can’t manage to do on its own. Also the adblue tank sensor got stuck due to crystals in the tank - only realised when I toped up and it wouldnt register as having a full tank of adblue - meaning I had something like 200 miles to get it fixed before the van would no longer start.
Thankfully between buying a carista to manage regens and a fair amount of forte adblue/fuel/oil treatments you can manage the problems but that seems very backwards…. I was sceptical when my mechanic suggested the additives but fortunately I trust him as I know he’s very good…. Think I’d have been up s
t creek if I’d been relying on out of warranty main dealer fixes.
Maybe not much development went into the small euro 6 diesel engines as the manufacturer plan was to make do with them for a few years as they knew buyers would be forced away from diesels?
Thankfully between buying a carista to manage regens and a fair amount of forte adblue/fuel/oil treatments you can manage the problems but that seems very backwards…. I was sceptical when my mechanic suggested the additives but fortunately I trust him as I know he’s very good…. Think I’d have been up s
t creek if I’d been relying on out of warranty main dealer fixes.Maybe not much development went into the small euro 6 diesel engines as the manufacturer plan was to make do with them for a few years as they knew buyers would be forced away from diesels?
From a garage point of view, diesels are reliable, the emissions control systems are not. most common cars that cause issues for us are VW, they also seem to drink far more adblue than other manufactures.
E6 engines seem to clog up the intake manifolds more than E5, however the biggest issue seems to be adblue itself, again the worst seem to be VW group although more Audi than VW, Skoda and Seat. Ford have issues with some of the diesels wanting regular oil changes and software updates. We have seen a couple of issues with the Toyota proace and adblue, typically your looking at somewhere between £1000 and £2500 to repair an adblue system - its usually the pump that fails which comes complete with the tank. You can sometimes limit adblue faults by only buying adblue when you need it, don't store it as apparently it has a use by date and also don't buy it from a petrol station where they keep it out in the daylight as it turns it to water
E6 engines seem to clog up the intake manifolds more than E5, however the biggest issue seems to be adblue itself, again the worst seem to be VW group although more Audi than VW, Skoda and Seat. Ford have issues with some of the diesels wanting regular oil changes and software updates. We have seen a couple of issues with the Toyota proace and adblue, typically your looking at somewhere between £1000 and £2500 to repair an adblue system - its usually the pump that fails which comes complete with the tank. You can sometimes limit adblue faults by only buying adblue when you need it, don't store it as apparently it has a use by date and also don't buy it from a petrol station where they keep it out in the daylight as it turns it to water
stevemcs said:
You can sometimes limit adblue faults by only buying adblue when you need it, don't store it as apparently it has a use by date and also don't buy it from a petrol station where they keep it out in the daylight as it turns it to water
That’s what I was told by the guy who put me onto all the forte treatments…. Pretty much treat it like buying milk?I’m definitely not chancing another break down and will always chuck in one of the adblue additives (sounds as ridiculous as it is!) as well now.
I read some cars (I recall JLR particularly) can be fussy on AdBlue so I only used "VW" AdBlue from TPS in case I ever had a fault and they blamed the fluid used. Maybe 18mths ago TPS coudln't get it so switched to Redex AdBlue from Costco. I just dropped 5 litres in now and again which would last us about 6 mths - apparently if you fill it right up it can mess up the ultrasonic level sensor.
I also ran the car on Shell V-Power for most the time we had it - supposedly it keeps everything cleaner and car regens less. Then then price, even just using a tank a month, became unbearable so switched to Cosco's Premium diesel. By chance a glow plug failed on the first tank of Costco fuel. Anyway, couldn't tell really tell any difference between either fuel but possibly the engine was slightly smoother and less clattery with the Costco stuff. MPG was exactly the same.
I also ran the car on Shell V-Power for most the time we had it - supposedly it keeps everything cleaner and car regens less. Then then price, even just using a tank a month, became unbearable so switched to Cosco's Premium diesel. By chance a glow plug failed on the first tank of Costco fuel. Anyway, couldn't tell really tell any difference between either fuel but possibly the engine was slightly smoother and less clattery with the Costco stuff. MPG was exactly the same.
JLR we only use genuine but they are pretty good using it, probably 15k out of 10 litres. We did have someone ignore the no start message the other week and that had to be recovered in and messed about with.
Vauxhall and VW like glow plugs, randomly number 2 glowplug seems to be the most common to fail on VW's then number 4
Vauxhall and VW like glow plugs, randomly number 2 glowplug seems to be the most common to fail on VW's then number 4
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