Modern Diesels & Reliability
Discussion
With the mileage our household does, we would really benefit from a diesel.
Does anyone have anything nice to say about them?
Unfortunately we have been badly scarred by past ownership.
Several years ago (maybe ~2013) we had a couple of the earlier DPF-equipped diesels, ex dealer demos bought when a few months old, and despite making very few short/slow-speed journeys, they still blocked their DPFs and went into limp mode, always many miles from home.
On one occasion one of the cars *began* its DPF regen immediately after dropping off the A11 into Norwich city traffic after an hour-long run at 70-75mph from Cambridge.
The dealer fixing the blocked DPFs could see from the trip computer average speed (and dashcam footage leading up to limp mode) that they were not sitting in town traffic or making short journeys so they reset the software and regenerated them under warranty but the problem recurred every few months.
We lost confidence and sold the cars at a big loss before the 3yr warranty expired, moving to petrol which has been 100% trouble-free, albeit more costly to run.
Then I read on this forum about JLR's allegedly bodged DPF regen arrangement causing similar problems to what I experienced which causes me to hesitate even more.
But between the wife and I, we cover nearly 50k miles per year, mostly out of town. In theory a diesel would be perfect for us.
Do you have anything nice to say about a modern diesel? Particularly EU-6 ULEZ compliant ones although I'd have an EU-5 non-ULEZ one if necessary and use another (petrol) car for London.
Does any manufacturer stand out as having got the emissions equipment/software right?
Thanks,
R
Does anyone have anything nice to say about them?
Unfortunately we have been badly scarred by past ownership.
Several years ago (maybe ~2013) we had a couple of the earlier DPF-equipped diesels, ex dealer demos bought when a few months old, and despite making very few short/slow-speed journeys, they still blocked their DPFs and went into limp mode, always many miles from home.
On one occasion one of the cars *began* its DPF regen immediately after dropping off the A11 into Norwich city traffic after an hour-long run at 70-75mph from Cambridge.
The dealer fixing the blocked DPFs could see from the trip computer average speed (and dashcam footage leading up to limp mode) that they were not sitting in town traffic or making short journeys so they reset the software and regenerated them under warranty but the problem recurred every few months.
We lost confidence and sold the cars at a big loss before the 3yr warranty expired, moving to petrol which has been 100% trouble-free, albeit more costly to run.
Then I read on this forum about JLR's allegedly bodged DPF regen arrangement causing similar problems to what I experienced which causes me to hesitate even more.
But between the wife and I, we cover nearly 50k miles per year, mostly out of town. In theory a diesel would be perfect for us.
Do you have anything nice to say about a modern diesel? Particularly EU-6 ULEZ compliant ones although I'd have an EU-5 non-ULEZ one if necessary and use another (petrol) car for London.
Does any manufacturer stand out as having got the emissions equipment/software right?
Thanks,
R
The biggest issue with modern engines is the amount of additional complexity that goes into reducing emissions, and diesels are the hardest hit by it (especially large commercial engines).
BUT, if you're doing big miles and getting the engine up to temperature most journeys, there's no reason you shouldn't happily run a modern diesel engine into big mileages without issues.
The problem is, most people's usage cycles don't suit the technical limitations of the emissions garb and it harms reliability. Short journeys on cold engines simply don't suit modern diesels.
I suspect that maybe you and your wife drive very gently, and sometimes an Italian tune up is very beneficial.
BUT, if you're doing big miles and getting the engine up to temperature most journeys, there's no reason you shouldn't happily run a modern diesel engine into big mileages without issues.
The problem is, most people's usage cycles don't suit the technical limitations of the emissions garb and it harms reliability. Short journeys on cold engines simply don't suit modern diesels.
I suspect that maybe you and your wife drive very gently, and sometimes an Italian tune up is very beneficial.
Despite my employer not selling any diesels, I don't really have anything bad to say about modern diesels, I'm in and out of new cars every few months and like for like (e.g. 190PS Audi A4 petrol vs 190PS Audi A4 diesel) I'd always choose the diesel because I do a lot of miles and they are far more economical and effortless on a cruise. Admittedly these are always new cars and I don't run them for very long but I've never had any issues related to the diesel system, other than an injection pump on a 22 year old Passat, at 212k miles.
For short trips or city driving, I'd pick a petrol still, but for the mileage you're talking about, diesel makes perfect sense. Also I've had a Prius before at 90k miles, and if I was considering that class/segment of car, I would pick a hybrid over petrol/diesel all day long. Real world economy was good, and the car was impeccably reliable.
I know people who have had DPF or Turbo or injector or whatever issues on their cars, but other than the DPF the same applies to petrols...
Taxis are still predominantly diesels, with some hybrids thrown in, so the majority of diesels must be fit for purpose
If you drive into city centres much, obviously consider limitations of buying a pre-Eu6 diesel as they will start getting gradually banned from certain zones.
For short trips or city driving, I'd pick a petrol still, but for the mileage you're talking about, diesel makes perfect sense. Also I've had a Prius before at 90k miles, and if I was considering that class/segment of car, I would pick a hybrid over petrol/diesel all day long. Real world economy was good, and the car was impeccably reliable.
I know people who have had DPF or Turbo or injector or whatever issues on their cars, but other than the DPF the same applies to petrols...
Taxis are still predominantly diesels, with some hybrids thrown in, so the majority of diesels must be fit for purpose
If you drive into city centres much, obviously consider limitations of buying a pre-Eu6 diesel as they will start getting gradually banned from certain zones.
OP - what car was it you had all this trouble with?
Other than JLR everyone else seems to have sorted out the DPF issue 10+ years ago; my Volvo D5 did lots of motorway driving and had no issue and ex wifes 4 year old XC60 does mostly round town trips with very occasional motorway/DC driving and has had no issues at all. DPFs do need replacing at circa 10 years / 150K miles (your mileage may vary) but up until then should be trouble free. If you avoid JLR you really shouldn't have any problems.
Other than JLR everyone else seems to have sorted out the DPF issue 10+ years ago; my Volvo D5 did lots of motorway driving and had no issue and ex wifes 4 year old XC60 does mostly round town trips with very occasional motorway/DC driving and has had no issues at all. DPFs do need replacing at circa 10 years / 150K miles (your mileage may vary) but up until then should be trouble free. If you avoid JLR you really shouldn't have any problems.
Actually Im being unfair, as per the Jaguar TSB document doing the rounds I think the well known JLR problems are on the cars based on the ancient EUCD platform. Disco Sport, E-Pace, etc where there isn't the room for a close coupled DPF so it's under the floor of the car.
The cars that aren't made from 20 year old Ford leftovers are fine?
The cars that aren't made from 20 year old Ford leftovers are fine?
stickleback123 said:
The cars that aren't made from 20 year old Ford leftovers are fine?
But are they?JLR have their problems but I read about plenty of BMW diesels with timing chain failure or lunching their swirl flaps. A concern although not technically related to emissions equipment (or is it? - oil contamination from regens maybe affecting timing chain lubrication?)
And I read about VWs post-dieselgate having numerous problems after being mapped to comply with emissions which they previously cheated.
Edited by Ron99 on Friday 26th June 14:55
I have a modern ish diesel with plenty of miles on it. I wouldn't have another.
No DPF problems, but plenty of injector problems and things like DMFs are now standard service items.
They're built to get past legislation, not to run trouble free into the future. So is every car of course but the kuldges they've created were a lot less complex in previous generations.
No DPF problems, but plenty of injector problems and things like DMFs are now standard service items.
They're built to get past legislation, not to run trouble free into the future. So is every car of course but the kuldges they've created were a lot less complex in previous generations.
Ron99 said:
And I read about VWs post-dieselgate having numerous problems after being mapped to comply with emissions which they previously cheated.
I've got a MK6 Golf GT diesel with 103k on it now. Had the emissions fix back in about 2016. Only engine/exhaust trouble I've had was a throttle position sensor error, which was remedied by the garage cleaning out the throttle body (not an expensive fix).Edited by Ron99 on Friday 26th June 14:55
Might be a sales cliche, but I really do always run it on V-Power, as I'm sure it helps longevity of injectors.
Edited by Fusion777 on Saturday 27th June 11:29
Going off on a tangent... because PH... the fuel economy benefits of a diesel vs a petrol are significantly smaller these days. I drive a lot of different brands and models of car when travelling for work, and found the VAG range of Golf-sized cars with 4 cylinder petrol engines that can switch to 2-cylinder running are incredibly fuel efficient. Not quite as efficient but a notable mention are the Mercedes A-classes where it turns the engine off when coasting, and the Peugeot 308 with an 8-speed auto.
I've not encountered the "2-cylinder running" in bigger VAG cars though... either because it isn't available or because the conditions to switch to 2-cylinder are never reached. Also I had a big Citroen with the same engine as the 308 and it felt horribly underpowered due to the extra weight and the MPG reflected the need to work the engine harder.
Modern V8s can run on 4-cylinders so... that's an option too
I've not encountered the "2-cylinder running" in bigger VAG cars though... either because it isn't available or because the conditions to switch to 2-cylinder are never reached. Also I had a big Citroen with the same engine as the 308 and it felt horribly underpowered due to the extra weight and the MPG reflected the need to work the engine harder.
Modern V8s can run on 4-cylinders so... that's an option too
donkmeister said:
Going off on a tangent... because PH... the fuel economy benefits of a diesel vs a petrol are significantly smaller these days. I drive a lot of different brands and models of car when travelling for work, and found the VAG range of Golf-sized cars with 4 cylinder petrol engines that can switch to 2-cylinder running are incredibly fuel efficient. Not quite as efficient but a notable mention are the Mercedes A-classes where it turns the engine off when coasting, and the Peugeot 308 with an 8-speed auto.
I've not encountered the "2-cylinder running" in bigger VAG cars though... either because it isn't available or because the conditions to switch to 2-cylinder are never reached. Also I had a big Citroen with the same engine as the 308 and it felt horribly underpowered due to the extra weight and the MPG reflected the need to work the engine harder.
Modern V8s can run on 4-cylinders so... that's an option too
Unbiased and accurate mpg figures are hard to find. Some drivers claim unbelievably good figures for their car while other drivers claim unbelievably bad figures.I've not encountered the "2-cylinder running" in bigger VAG cars though... either because it isn't available or because the conditions to switch to 2-cylinder are never reached. Also I had a big Citroen with the same engine as the 308 and it felt horribly underpowered due to the extra weight and the MPG reflected the need to work the engine harder.
Modern V8s can run on 4-cylinders so... that's an option too
You mention VW so I looked up some typical mpg figures for manual-box Golfs gathered by an apparently Honest bloke called John.
Here are the mpg for engines of similar horsepower:
1.4 TSI 150: 46
1.5 TSI 150: 42
2.0 TDI 150: 53
So let's say about 20% difference. It used to be reckoned about 30% difference. Perhaps modern direct injection petrols have closed the gap by 10%.
With petrol engines now being turbocharged, direct injected, fitted with particle filters and prone to carbon deposits and pre-ignition, I'm not sure a TSI engine would be any more reliable than a TDI.
Ron99 said:
On one occasion one of the cars *began* its DPF regen immediately after dropping off the A11 into Norwich city traffic after an hour-long run at 70-75mph from Cambridge.
Wife has had an EU6 Tiguan for coming up to 5yrs and it did a dpf regen on the school run the day after a fast weekend blast over the M62 and back. Some guys on the one of the VW forums monitored the dpf temp on a Golf and they don't get anywhere near the temps required for passive regen in normal UK use. This idea of taking them for a blast in nonsense - you just can't get enough load on the engine to heat the dpf up. The VW EA288 engine is programmed to do an active regen after 465 miles anyway if it hasn't done one earlier.Touching a massive a massive piece of wood, our Tiguan does 4 mile school runs, trips to shops etc. It seems to regen about every 300 miles and we're forever turning it off mid-regen (some people say they can tell, we can't until we get out of the car and the fan is roaring). Only non-standard thing is the car is always run on V-Power.
The car does terrify me though - the emissions system with multiple cooling systems (which does make the heater warm up amazingly quickly), EGRs, Ad-Blue etc is ferociously complicated.
I have probably mentioned this once or twice but my 2011 E220 has done 316k miles with no significant issues of any sort, and continues to plod on.
Over that mileage I have averaged 45 ish mpg and can still easily get mid 50's on a longer runs. It was initially used as a chauffeur vehicle doing 90k plus miles for 3 years, where the overall average was nearer 50mpg.
The last 5 years it has been "retired" and has averaged under 8k miles a year, so it has covered both extremes without issue or complaint.
but my 2011 E220 has done 316k miles with no significant issues of any sort, and continues to plod on.Over that mileage I have averaged 45 ish mpg and can still easily get mid 50's on a longer runs. It was initially used as a chauffeur vehicle doing 90k plus miles for 3 years, where the overall average was nearer 50mpg.
The last 5 years it has been "retired" and has averaged under 8k miles a year, so it has covered both extremes without issue or complaint.
I posted this a couple of months ago...
My BMW X1 20d auto had a recall to look at the EGR valve and cooler at just TWO years old and approx 15,000 miles and was told by the tech at the time they had been problems with the diesels but mine had checked out OK.
Discussed it with the tech and he came across all vague and evasive when I challenged him on what was the problem and outcomes. It turns out he had updated the software in line with BMW recommendations and all was to be OK. This meant no new parts for my car, as had been done to some other cars. EGR and cooler.
He could not give me any explanation as to what the software changes and how it would affect my car. Mmmm! I mentioned the VW software updates pertaining to diesels and how it had affected the running detrimentally, and he was confident I would not have future problems. I did challenge him if I was to have future problems and should my car now get some new parts particularly the cooler and EGR valve. He said it was not necessary.
I was not convinced with his vague description of what the fix actual did and always have had doubts as to the longevity of the "fix" from that moment on.
Fast forwarding nearly two years and the X1 started stuttering under acceleration, took it in, interrogated the smart key and it came up with EGR valve fault straight away! new EGR valve required. Sales advisor said we can do that straight away as we have a healthy stock of those because common instance! Aaaargh!
The thing is, my car was now 4 years old and outside the 3 year warranty! Luckily I had taken out extended warranty and this covered part of the cost and it was obviously a pricey fix. A new EGR valve was fitted but it still suffers from a slight hesitation under acceleration that was not originally there.
Consequently I have lost all faith in the car, and in diesels in general because of the complicated emission controls that do seem problematic.
I've had a few diesels in the past, with and without dpf's and have never had any problems whatsoever, and these being much "lesser" Marques too.
So in conclusion, I think it is a false economy buying a Diesel engine model as IF you ever have problems with the emission controls equipment it will easily wipe out any benefit of greater mpg.
My BMW X1 20d auto had a recall to look at the EGR valve and cooler at just TWO years old and approx 15,000 miles and was told by the tech at the time they had been problems with the diesels but mine had checked out OK.
Discussed it with the tech and he came across all vague and evasive when I challenged him on what was the problem and outcomes. It turns out he had updated the software in line with BMW recommendations and all was to be OK. This meant no new parts for my car, as had been done to some other cars. EGR and cooler.
He could not give me any explanation as to what the software changes and how it would affect my car. Mmmm! I mentioned the VW software updates pertaining to diesels and how it had affected the running detrimentally, and he was confident I would not have future problems. I did challenge him if I was to have future problems and should my car now get some new parts particularly the cooler and EGR valve. He said it was not necessary.
I was not convinced with his vague description of what the fix actual did and always have had doubts as to the longevity of the "fix" from that moment on.
Fast forwarding nearly two years and the X1 started stuttering under acceleration, took it in, interrogated the smart key and it came up with EGR valve fault straight away! new EGR valve required. Sales advisor said we can do that straight away as we have a healthy stock of those because common instance! Aaaargh!
The thing is, my car was now 4 years old and outside the 3 year warranty! Luckily I had taken out extended warranty and this covered part of the cost and it was obviously a pricey fix. A new EGR valve was fitted but it still suffers from a slight hesitation under acceleration that was not originally there.
Consequently I have lost all faith in the car, and in diesels in general because of the complicated emission controls that do seem problematic.
I've had a few diesels in the past, with and without dpf's and have never had any problems whatsoever, and these being much "lesser" Marques too.
So in conclusion, I think it is a false economy buying a Diesel engine model as IF you ever have problems with the emission controls equipment it will easily wipe out any benefit of greater mpg.
Sheepshanks said:
Touching a massive a massive piece of wood, our Tiguan does 4 mile school runs, trips to shops etc. It seems to regen about every 300 miles and we're forever turning it off mid-regen (some people say they can tell, we can't until we get out of the car and the fan is roaring).
On my Scirocco you can tell it's in the middle of a regen as the idle speed is a couple of hundred rpm higher while it's occuring.As has been mentioned it is generally the additional emissions stuff that breaks on diesels, the core engine tends to be pretty solid.
For basic diesel engines the PSA 1.6 and the Renault 1.5 don't have too many bells and whistles bar the obligatory DPF. Not over engineered and easy enough to work on.
Used a 1.5 DCI for best part of 40K with mixed driving and a 1.6 PSA for 60K, couldn't honestly tell you I was ever aware of either doing a regen.
Had a VW 1.6 CR in a golf and that was unreal under the bonnet in comparison, horrid thing to work on but a nice refined engine for a dag dag.
For basic diesel engines the PSA 1.6 and the Renault 1.5 don't have too many bells and whistles bar the obligatory DPF. Not over engineered and easy enough to work on.
Used a 1.5 DCI for best part of 40K with mixed driving and a 1.6 PSA for 60K, couldn't honestly tell you I was ever aware of either doing a regen.
Had a VW 1.6 CR in a golf and that was unreal under the bonnet in comparison, horrid thing to work on but a nice refined engine for a dag dag.
I do 22k miles a year in my 2018 520d touring. It’s magnificent- it wafts about you can’t hear engine inside. It has been faultless.
I took it to south of France where it near as dammit did 1000 miles on a tank of diesel with 4 people on board and luggage.
Drives beautifully, has all performance you need from daily driver- it’s just ace. Would recommend!
I took it to south of France where it near as dammit did 1000 miles on a tank of diesel with 4 people on board and luggage.
Drives beautifully, has all performance you need from daily driver- it’s just ace. Would recommend!
cuprabob said:
On my Scirocco you can tell it's in the middle of a regen as the idle speed is a couple of hundred rpm higher while it's occuring.
It seems to idle anywhere between 800 and 1000 rpm anyway, so can't tell from that. I've seen all sorts of things - people say the exhaust note changes, hangs on to gears longer (it's a DSG) etc but I really can't tell and, although it's wife's car, I drive it quite a bit. At home it's parked against the garage door with a wall to the right yet you still can't hear the noise from the cooling fan until you open the door - and it's pretty loud.The one definite thing is stop/start is disabled, but we turn that off anyway as it's over-eager to shut the engine off.
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