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Model specific boards => Golf mk7 => Topic started by: Optimus prime on 02 August 2015, 17:46
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Guys,
Having a full copy of VCDS I have been monitoring my car's regens etc & logging the results. In a nut shell the results and regen conditions are below: These tests have been on normal diesels but I am now running on BP ultimate to see if any thing differs.
Car regens every 500 miles approx
During a regen the stop/start fails to operate
Car idle's at just over 1000 rpm instead of 800
Fans running after the car has been turned off is the sign of a very recent completed regen & is part of the cool down process. It does not happen during the regen as heat needs to be maintained for the process to complete.
Hope this helps
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The regens aren't mileage dependent they're triggered when the carbon mass reaches a certain limit. If the appropriate conditions aren't met during driving and the regen can't start or is shut off before it can complete there is another trigger level for the dpf warning light to come on telling you to go thrash the car so it can run a regeneration routine.
If the light is ignored the final trigger level will put on the engine management light and usually a flashing glow plug light along with limp mode meaning the dpf will need a forced regeneration.. then there is the "safety" carbon mass level at which point the car and/or diag tools will reject the forced regen due to risk of fire (although there is still a way to trick it in to working). It should never really get to that final stage though unless there is a fault somewhere else in the engine that is ignored... anything that messes with the airflow through the engine so throttle body, egr valve, intake runners and boost leaks are the usual culprits along with faulty pressure sensor or temp sensors in the dpf.
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The regens aren't mileage dependent they're triggered when the carbon mass reaches a certain limit. If the appropriate conditions aren't met during driving and the regen can't start or is shut off before it can complete there is another trigger level for the dpf warning light to come on telling you to go thrash the car so it can run a regeneration routine.
If the light is ignored the final trigger level will put on the engine management light and usually a flashing glow plug light along with limp mode meaning the dpf will need a forced regeneration.. then there is the "safety" carbon mass level at which point the car and/or diag tools will reject the forced regen due to risk of fire (although there is still a way to trick it in to working). It should never really get to that final stage though unless there is a fault somewhere else in the engine that is ignored... anything that messes with the airflow through the engine so throttle body, egr valve, intake runners and boost leaks are the usual culprits along with faulty pressure sensor or temp sensors in the dpf.
Hi,
Yes I am aware of all the criteria thank you, having driven diesels for over 15 yrs most with dam DPF's! The mileage I quoted was simply a guide as to how my car regens based on its use of only a 28 mile round trip everyday. The soot loading is the factor as you state but it will be interesting to see if by using a super fuel if the the regens take place at a higher mileage interval or indeed less frequent?
Also I plan to fit a DTUK box at some point and then do this research again as some have said that these boxes have also reduced the number of regens although I am a little sceptical on this as in my experience any typical form of engine mapping / enhancement tends to increase soot loading.
By the way "thrashing" is not required a steady 20 min run in sports mode (with a higher gear) with the rev's above 2000 rpm will do the trick, & just wait for the light to go out. Or use VCDS and start a standing/idle regen process & go and put the kettle on!
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Was merely pointing out that not everyone can base their regen frequency on your own particular daily drive, some people (who don't really need a diesel) will be doing far less miles and with low speed stop/start driving. I would be very surprised if you ever see your own dpf dash light come on.
I see little to no difference with these so-called super fuels when it comes to frequency of regens, they do seem to help the process complete a little faster though. Poorly refined remaps certainly lead to increased soot loads but those that burn clean tend not to have any negative effects. I've never played with the DTUK boxes but I know they are superior to the oldskool resistor boxes which just overfuel and lead to premature dpf failure.
Thrashing is subjective, holding a diesel for prolonged periods over 2000rpm is counter-intuitive to most. 50mph in 4th gear at steady load I find works best.. I would also advise against using the emergency forced regen unless absolutely necessary as it will shorten the life of the dpf, allowing the ash content to build up faster than normal.
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Was merely pointing out that not everyone can base their regen frequency on your own particular daily drive, some people (who don't really need a diesel) will be doing far less miles and with low speed stop/start driving. I would be very surprised if you ever see your own dpf dash light come on.
I see little to no difference with these so-called super fuels when it comes to frequency of regens, they do seem to help the process complete a little faster though. Poorly refined remaps certainly lead to increased soot loads but those that burn clean tend not to have any negative effects. I've never played with the DTUK boxes but I know they are superior to the oldskool resistor boxes which just overfuel and lead to premature dpf failure.
Thrashing is subjective, holding a diesel for prolonged periods over 2000rpm is counter-intuitive to most. 50mph in 4th gear at steady load I find works best.. I would also advise against using the emergency forced regen unless absolutely necessary as it will shorten the life of the dpf, allowing the ash content to build up faster than normal.
Yes I agree I could probably do without a diesel but the torque is just great :smiley: I have noticed an increase of 4 mpg over my normal journey using bp ultimate but shell nitro + was no different over normal fuel. It will be interesting to see if the regens are a little less frequent or more spaced out on ultimate, traditionally I would go for a decent obd remap from Emaps as he has done all my cars in the past and can do the mk7 but I still have over 2 yrs warranty left & as you we all know sometimes " if you play you pay" espically if your unlucky enough to have a large engine or gearbox claim.
Yes the emergency dpf regen process is exactly that if really necessary I would program the regen while driving process instead. However as these cars give you some indication via the dash light it is much easier to sort out unlike BMW diesels where the dpf light is an indication all to late !
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I wouldn't worry about the dpf and just drive the car. I've never had any light or problems with the dpf and I do 3 miles to work and 3 miles back 5 days a week. Mine seems to regen every 800 miles or so no matter what the driving conditions are (it started doing one after I'd driven to the Isle of Skye). These new diesel engines are nothing like the old ones so stop worrying about the dpf.
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I wouldn't worry about the dpf and just drive the car. I've never had any light or problems with the dpf and I do 3 miles to work and 3 miles back 5 days a week. Mine seems to regen every 800 miles or so no matter what the driving conditions are (it started doing one after I'd driven to the Isle of Skye).
Not worrying I know enough about them, just passing on my little knowledge to those that may not. People need to be aware because up until the MK7 when they moved the dpf closer to the engine things were not so good. Prevention is better than cure.
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Totally agree but I doubt you'll even need to do anything with this dpf on your mk7.
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I did read somewhere that a low fuel level can also inhibit the regen cycle?
Not sure if that's what the Golf logic works like though?
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Totally agree but I doubt you'll even need to do anything with this dpf on your mk7.
No I think you right having spent many years fighting and fixing DPF's issue's on BMW's it would be nice to have a break :smiley: BMW software (DIS) is so unfriendly & clunky to use, VCDS is a breeze compared
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I did read somewhere that a low fuel level can also inhibit the regen cycle?
Not sure if that's what the Golf logic works like though?
Yes correct you must have at least 1/4 of a tank it forms part of the regen criteria like a lot of cars
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We just need more English data files in vcds now :grin:
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BTW, I think understanding the system logic behind the regen cycle is useful information - I've had oil burners for years, but never really truly understood how exactly this works.
That the "mad fan" is a post-burn symptom is interesting for example.
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Yes correct you must have at least 1/4 of a tank it forms part of the regen criteria like a lot of cars
I never knew that. Some folk only ever put £10 to £15 in of fuel at a time. They will be causing all sorts of problems.
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Had a look with VCP on oil ash level today.... at 75k miles I am at 26.8g. DPF limit being 80g, which means that it should last for another 150k miles. :shocked:
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Had a look with VCP on oil ash level today.... at 75k miles I am at 26.8g. DPF limit being 80g, which means that it should last for another 150k miles. :shocked:
Yep looked after I would say that's possible. Bmw used to say check @120k but they phased it out when the LCI cars came out with a combined cat & dpf fitted closer to the the engine bay. I did read about a 3ltr Bm doing 225K on the original dpf and that was on a 2007 car. Technology has moved on a lot since then as well.
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Nah you can abuse it :D As long as you only drive long distances you're OK ;)
What really seems to kill them off is short journeys.
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Nah you can abuse it :D As long as you only drive long distances you're OK ;)
What really seems to kill them off is short journeys.
What really kills them is people's ignorance to the warning lights :whistle:
My A3 PD170 had the DPF in for 50k, nearly 20K of which was mapped miles and for the first 18 months did a round trip of 8 miles per day with the occasional blast in between. I never once saw the DPF light or even had the car doing an active regen (revs never increased when sat stationary)
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Regen criteria is similar for most derv cars & the MK7 is no different. See below these factors what are typically looked for by the ECU before it starts the process:
1. Over 1/4 tank of fuel
2. ECT over 70C
3. Speed about 40 mph
Obviously the process will only start if the soot loading requires it to. If monitored by VCDS you can expect to see the temps before and after the DPF hit 600C+ during a full dpf regen.
Typically it is very short journey's (without a long run once a month) and the fact that the ECT never reaches above 70C that causes issues. Also the lack of knowledge regarding the dash light :rolleyes:
This is just a rough guide but for those that only do 2 miles a day and always run on less than 1/4 tank of fuel I would consider other options or a little more house keeping with regards to the way you use / drive your car
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Another trigger is the pre-turbo temps need to be above 700C to activate a regen :nerd:
Good luck doing that in 4th at 40mph as per the handbook :whistle:
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Another trigger is the pre-turbo temps need to be above 700C to activate a regen :nerd:
Good luck doing that in 4th at 40mph as per the handbook :whistle:
Your forgetting that the car will double inject to raise the temp (hence the poor mpg) & most turbo's run above 500C normally so the extra temp will not be difficult to get to if you run the car in manual sport mode & keep the rpm above 2K.
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Another trigger is the pre-turbo temps need to be above 700C to activate a regen :nerd:
Good luck doing that in 4th at 40mph as per the handbook :whistle:
Your forgetting that the car will double inject to raise the temp (hence the poor mpg) & most turbo's run above 500C normally so the extra temp will not be difficult to get to if you run the car in manual sport mode & keep the rpm above 2K.
Hence why I said 'good luck doing it in 4th'. Sat at 40mph the car generally runs at 300C unless going up a hill
The car simply doesn't reach those temps at that speed; much better to run the car in 3rd gear at 50mph
I've done a few forced regens for people over the years..... :smiley:
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Another trigger is the pre-turbo temps need to be above 700C to activate a regen :nerd:
Good luck doing that in 4th at 40mph as per the handbook :whistle:
Your forgetting that the car will double inject to raise the temp (hence the poor mpg) & most turbo's run above 500C normally so the extra temp will not be difficult to get to if you run the car in manual sport mode & keep the rpm above 2K.
Hence why I said 'good luck doing it in 4th'. Sat at 40mph the car generally runs at 300C unless going up a hill
The car simply doesn't reach those temps at that speed; much better to run the car in 3rd gear at 50mph
I've done a few forced regens for people over the years..... :smiley:
Yes me to and to be honest I would take 40mph as the min speed required. I usually do it on a motorway @ a steady 60 mph for about 20 mins as I find this works best. With my laptop plugged in you can monitor all that is required
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An interesting thread for sure.
Like McMaddy, my weekly routine is relatively small journeys (10 miles to work and 12 miles back - (different route on the way back before you ask)). My route home is usually Motorway for about 8 or 9 miles @ 65-75mph.
Whilst I've never had the DPF light come on the dash in nearly 2 years of ownership, I do experience quite a few regens (stop start turned off, engine revs raised), at least once every couple of weeks or so (so about 200-300 miles), so no where near the 800 miles McMaddy is getting between his regens ?
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An interesting thread for sure.
Like McMaddy, my weekly routine is relatively small journeys (10 miles to work and 12 miles back - (different route on the way back before you ask)). My route home is usually Motorway for about 8 or 9 miles @ 65-75mph.
Whilst I've never had the DPF light come on the dash in nearly 2 years of ownership, I do experience quite a few regens (stop start turned off, engine revs raised), at least once every couple of weeks or so (so about 200-300 miles), so no where near the 800 miles McMaddy is getting between his regens ?
Lets face it monitoring dpf regens with accurate figures is child's play if you have vcds. Just select 507 measuring block and convert the figure that is in metre's into miles and deduct from your speedo. This will give you almost the exact mileage when your last regen was completed. Use this as a base point and recheck 507 after a few weeks easy. I think Mcmaddy's figures maybe off slightly and without doing the above it is difficult to be accurate. We have to remember that fuel quality plays a major part and I don't mean the cheapest. My local indy VW tech swears by BP ultimate for our engines with regards to fewer regens due to less soot production so I am currently testing with a full tank just to see. In theory with a cleaner burn you get less soot so this should work out but we will have to wait and see, if it does I am more than happy to spend an extra £5 per full tank fill up for the results especially as my trip to work is only 14 miles each way and as we no regens hurt your mpg.
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I only ever use esso or shell and occasionally give it done shell v power when the price is low. I also use millers diesel power plus every fill up so maybe that is helping with regens too.
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I only ever use esso or shell and occasionally give it done shell v power when the price is low. I also use millers diesel power plus every fill up so maybe that is helping with regens too.
Millers increase's the cetane by 4 which makes it the same as bp ultimate from a burn point but unsure if it increases the clean level to the same quality? Used it in my 535d but never noticed any difference other than the smell of the stuff in the boot :rolleyes: Will see how the ultimate works out then perhaps try normal derv + millers.
@ Mcmaddy are you regens measured via vcds or just the feeling of the car with noted mileage? With your driving distance I can't believe the regens are every 800 miles or is that when it happened? As driving 3 miles each way 5 days a week you won't even meet the ECT criteria for the regen process let along a full regen.
Forgot to mention the Mk7 does not passive regen
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I can do short journeys for a fortnight and then go out for a good drive on a weekend. It just seems the fans are blaring away at approximately 800 miles ish, can be less miles but strange it always happens at the end of a decent drive out.
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I think you may not notice all regens. :tongue:
Even I don't get 800 miles between them and on average my journeys are around 100 miles - one way.
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Possibly. Could just be coincidence that it looks like 800 miles between when in fact it's done some in between.
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Possibly. Could just be coincidence that it looks like 800 miles between when in fact it's done some in between.
I think your find its because you only hit the criteria then I bet if you run vcds you would find that your soot loading was quite high due to the short trips and the long run ticks all the boxes for a regen. So it kind of gives the impression of a regen every 800 but that is not the case.
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This helps
https://www.youtube.com/watch?v=Iuf9a3P3brY
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There should be a light on the dash that tells you when its doing its regen.
I don't know how many times I've come home, parked on the drive and the fans have been going full pelt for at least 15minutes after me switching off.
I'd much rather just give it a blast on a nearby dual carriageway if I knew it was doing the regen when I was driving home.
That video was pants. Tells you nothing.
This ones not bad https://www.youtube.com/watch?v=aMKpo74P6SE
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There should be a light on the dash that tells you when its doing its regen.
I don't know how many times I've come home, parked on the drive and the fans have been going full pelt for at least 15minutes after me switching off.
I'd much rather just give it a blast on a nearby dual carriageway if I knew it was doing the regen when I was driving home.
Sorry your wrong the lamp only lights as a warning to say that your soot loading has reached a specific level and you therefore need to follow the instructions in the manual to clear it. If the car has been regenerating correctly on its own then this light should never appear.
Also a blast will not clear a blocked dpf nor will it speed up the regen process & it is not needed on the MK7 as they will regen perfectly when stationary once the process has started, hence the option in vcds to do a stationary emergency /service regen
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There should be a light on the dash that tells you when its doing its regen.
I don't know how many times I've come home, parked on the drive and the fans have been going full pelt for at least 15minutes after me switching off.
I'd much rather just give it a blast on a nearby dual carriageway if I knew it was doing the regen when I was driving home.
Sorry your wrong the lamp only lights as a warning to say that your soot loading has reached a specific level and you therefore need to follow the instructions in the manual to clear it. If the car has been regenerating correctly on its own then this light should never appear.
Also a blast will not clear a blocked dpf nor will it speed up the regen process & it is not needed on the MK7 as they will regen perfectly when stationary once the process has started, hence the option in vcds to do a stationary emergency /service regen
What do yo mean I'm wrong?? I never said there was a light. I said there should be a light to tell you its currently doing a regen as that would be much more beneficial.
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There should be a light on the dash that tells you when its doing its regen.
I don't know how many times I've come home, parked on the drive and the fans have been going full pelt for at least 15minutes after me switching off.
I'd much rather just give it a blast on a nearby dual carriageway if I knew it was doing the regen when I was driving home.
Sorry your wrong the lamp only lights as a warning to say that your soot loading has reached a specific level and you therefore need to follow the instructions in the manual to clear it. If the car has been regenerating correctly on its own then this light should never appear.
Also a blast will not clear a blocked dpf nor will it speed up the regen process & it is not needed on the MK7 as they will regen perfectly when stationary once the process has started, hence the option in vcds to do a stationary emergency /service regen
What do yo mean I'm wrong?? I never said there was a light. I said there should be a light to tell you its currently doing a regen as that would be much more beneficial.
Sorry reading on iphone I read it as "you should" already have a light not that it would be a good idea. My error :rolleyes:
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Sorry reading on iphone I read it as "you should" already have a light not that it would be a good idea. My error :rolleyes:
No bother. After reading it again myself I could see where you are coming from. :laugh:
It would definitely suit me better to be notified it was happening. I've had my neighbour come to the door before saying I've left my car running because of it!!
I even know someone who phoned Audi to say their car was faulty because all fans were blaring as they parked up and attempted to walk away :grin:
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I don't believe that the fans blaring at the end of a long journey is an indication of an active DPF regen going on in a MK7 Golf with a TDI engine. The DPF is right next to the exhaust manifold now rather than way down the exhaust system, so that it warms up quicker and can be effective from shorter journeys.
The DPF needs to cool down at the end of a long journey, and this is the reason the fans are blaring.
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The DPF needs to cool down at the end of a long journey, and this is the reason the fans are blaring.
Cheers.