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Car broke down on motorway the other day. its a 2011 golf 2.0 tdi cr 140. its a great car and does over 60mpg on decent runs which suits me.
The AA guy came and said the ego valve had gone. He'd done 5 that day on other cars. he blanked the thing off with a selection of plates he had with him and the fault light on the dash came on but the car drove ok.
Took it to my local mechanic chap. He said his mate offers an egr delete service. I took him up on this and great, no ego, no light and better fuel economy.
A month later the dpf light comes on. My wife didn't understand and just came home and then used the car again later as I was away.
I tried to get the car to do a drive by regen but the light wouldn't go off and then the coil light and "warning" go to a garage message came up and it went into limp mode.
Took it to my mech guy and he took it out of limp mode and did a forced dpf regen on his snap on diagnostic computer. It said the process had gone ok and the dpf was regenerated but the original dpf light on the dash hasn't gone off.
Any ideas?
Does the warning light need to be reset like the service indicator? Make sure you do longer trips in the car. Without the egr the engine will be cold for longer after start up.
How many times was it used after the dpf light came on?
And for what sort of journeys?
Was it affected by the VW emissions recall (and did you have it done?)
Blanking the EGR can in certain cases increase soot load as well, as the combustion/injection/air-fuel parameters may get out of whack. (Don't know enough about the VW software to be 100%)
It may also be as simple as that the DPF light can only be dealer reset (as above). Or may need some combination of button presses etc, or a diagnostics tool.
He used a snap on diagnostic tool and reset the limp mode lights but the dpi one didn't go out. could it be that it can only be reset with vw diag tool?
it was affected by the recall but on advice I didn't have it done.
It was used for mainly journeys less than 10 miles for a month or so with the odd good blowout in between times.
Mostly 10 miles?
That might get expensive if the DPF wasn't cleaned out first.
Might be time for a VW indie rather than a man with a diagnostic tool.
I think the 10 mile trips is your issue. To get the engine to regen on a long trip you need around 2-2.5k rpm uninterrupted for 10 mins before the cycle starts, then about 20 mins driving at 2-2.5K rpm. Does it have the right oil? You could be getting too much ash build up, short trips with oil getting past the control rings by would make this worse.
What mileage does it have on it?
100K miles
Regardless of the health of the DPF, given the new MOT rules you won't be going anywhere with a blanked EGR if it's found
Former owner of 60 plate Golf estate 2.0tdi here. Get rid, walk away. In a few years time the gearbox will fail anyway!
Our old one turned up with egr failure and refurbished box, so requiring another 1000-1500 spend to fix it (it was "fixed" car) and I reckon the dpf will die soon.
I think the 10 mile trips is your issue. To get the engine to regen on a long trip you need around 2-2.5k rpm uninterrupted for 10 mins before the cycle starts, then about 20 mins driving at 2-2.5K rpm.
What kind of speed are you doing to achieve that? My 3 series would be doing 80mph+ at 2000rpm.
I have the same engine in my T5. I was talking to my mate who is a bit of an expert on these sorts of things (He fixes all the problem cars the main dealers can't) about possibly blanking out the EGR on mine as it is a known problem. His immediately said it was a no-go unless the DPF is also removed as the 2 bits are so intrinsically linked on this engine that you cannot remove 1 without the other. And since the new MOT coming in may make DPF removal very expensive if found, he advised against it VERY strongly. For what it is worth he is always moaning about "the man down the road with a generic fault reader" trying to fix stuff. He is paying £1000s a year for access to VW diagnostic software (and the same again for other manufacturers) and is forever off on training weekends with Bosch and the like to keep abreast of the technology. Find yourself someone like him to sort your car out. I promise you it will work out cheaper in the long run.
What kind of speed are you doing to achieve that? My 3 series would be doing 80mph+ at 2000rpm.
Change down a gear?
I think the 10 mile trips is your issue.
Almost definitely.
To get the engine to regen on a long trip you need around 2-2.5k rpm uninterrupted for 10 mins before the cycle starts, then about 20 mins driving at 2-2.5K rpm.
Um. no. That's a piss poor passive regen. It's all about load, not engine speed. Even a 2011 MY car shouldn't need that level of abuse to regen. Unless it's broken.
Equally, driving everywhere at 1000-1200 rpm "to save fuel" won't do it much good either. You don't need to be pushing that hard. 20 miles at reasonable motorway speeds should be enough i.e. not stuck in traffic. Unless the DPF is properly full, as there comes a point when even a forced regen doesn't work properly. Which if it's been filled to the point of a warning light and then driven badly for a month, it's probably either gone past already, or was very close to it.
His immediately said it was a no-go unless the DPF is also removed as the 2 bits are so intrinsically linked on this engine that you cannot remove 1 without the other.
Sounds like VWs software hasn't got the ability to deal with the changes to the "system" caused by egr blanking then. Which is good in one way.
What kind of speed are you doing to achieve that? My 3 series would be doing 80mph+ at 2000rpm.
Change down a gear?
That isn't normal driving though is it.
ghostlymachines post makes sense though.
To get the engine to regen on a long trip you need around 2-2.5k rpm uninterrupted for 10 mins before the cycle starts, then about 20 mins driving at 2-2.5K rpm.
Um. no. That’s a piss poor passive regen. It’s all about load, not engine speed. Even a 2011 MY car shouldn’t need that level of abuse to regen. Unless it’s broken.
10 minutes at motor way speeds to get the engine up to operating temp which is required for regen.
2000rpm is approx 70 in 5th in a mk 5 golf , I don't imagine a mk 6-7 is much different. Put the car in 5th and drive closer to 2500rpm to allow having to slow for other cars and prevent the regen stopping. To get the car to regen exhaust temps need to be high and uninterrupted. This is an easier way of doing regen that ensure loading and keep EGT high when you don't know what they are.
Does that not fit with what you said Ghostlymachine?
This is probably happening as we agree with short trips interrupting the active regen.
Sensor, I reckon. I had one of these go, it stopped the regent mode from triggering, having replaced an EGR and DPF.
Every couple of weeks I take the car out for a blast down the motorway, keeping it above 2750rpm and the boost gauge high. That seems to work quite well.
Not really. Once the engine/filter is up to temp it should quite happily burn off soot at 1500rpm with sufficient load (not very much). Coasting down a (long) hill, or stopping in traffic might cause issues.
I know the last group i benchmarked (few years ago, Euro 5 cars IIRC) mostly needed to be out of "regen conditions" for something like 5 minutes before the DPF cooled enough for it to give up, and that included a Passat with pretty much the same engine.
2000-2500 won't hurt. But it's not needed.
Good point with sensors, can't remember who it was, but they put one of the sensors on the bottom of the exhaust run and condensation mixed with exhaust "products" used to run down the inside of the pipe and pool on and around the tip of the sensor........ sensors used to be swapped at service as part of the warranty.... about €200 a pop at the time.
The DSG cars will hold a gear down when it's needed for a regen. My Passat estate (2012) will happily regen at around 1800-2000 revs on the motorway. You know when it's doing it if you have the range screen showing. When the range starts dropping 5mile intervals every mile or so it's having a clear out. The throttle response and exhaust note change just a touch as well.
Anecdotally I have heard that the older cars (early dpf models) are not as 'intelligent' on the regen so can require a bit more deliberate hammering.
Don't forget there are two types of regen - I'm talking about a passive regen where you run the engine at higher rpm to get the egt up to the 600+ degrees C needed to burn off the soot in the DPF. This is needed if your journeys are too short for the active regen to work.
The dpf will regen at lower rpm during active regen because it injects extra fuel to act as a catalyst to burn off the soot and raise the temps to the 400 C needed in that scenario.
If you keep stopping during active regen you will end up with fuel in your sump. If I remember rightly the hand book said you need to do 25 miles a day for a dpf equipped car. My wife does 26 miles in total. 2 x 13 is not enough in normal UK commuting conditions. When the light comes on and I take it on my 40 mile duel carriage way commute, there is too much speed variation (traffic, roundabouts etc) to regen. So I do what I said and that works, less than 2k rpm or more than 2.5k rpm and the light stays on.
anyone know a good vw independent mechanic near Southampton?
I use the guy who arranged the work as I've been using him for yrs since he started doing my vw van as he's a van specialist. Usual jobs are brake pads, services, nuts and bolts stuff that I guess hasn't changed much over the years. he's been really good and helpful but I think this issue was a job too far.
I'm pretty certain that blanking/ deleting the egr on these cars without deleting the dpf has caused the issue.
Apart from this episode it has been a great car. We've had it 3 yrs and its been very economical and cheap to run (until now...), and it looks nice as its a sport line and its great to drive. We were looking to move it on over the next couple of months typically...
I’m pretty certain that blanking/ deleting the egr on these cars without deleting the dpf has caused the issue.
Would't it produce less soot with the egr deleted?
Advice on the EGR valve is not to remove it unless you've also removed the DPF. Removing the EGR increases the amount of soot produced which clogs the DPF, probably to the point where it won't regen so you'll need to remove the DPF as well, and get the software on the ECU changed.
Removing any part of the emissions system is illegal and an MOT failure.
My advice is to get the car fixed properly ASAP so that all the emissions stuff is working as it should. The EGR fix won't be cheap, add the cost of a new DPF and it'll cost more to fix than the car's worth.
Don’t forget there are two types of regen
Yeah, i know all about the different types of regen. Well, the 4 or 5 types they had when i last worked on emissions development.
Would’t it produce less soot with the egr deleted?
Depends on how smart the engine software is, and how well it adjusts the fueling/boost and suchlike to account for the lack of exhaust products in the cylinder. TBH as the EGR is a part of the legally required aftertreatment system there is no incentive for manufacturers to make the software that adaptive. Just make sure there are diagnostics for the EGR (and DPF!!) so it flags up a fault and then either goes into a safe mode or limp home.
I know some manufacturers did have the flexibility to completely delete or close off the EGR with no ill effects, but that was a few years ago. I've moved on three or four times since then. And the emissions regs have changed more than once.
Theres two types of particle being collected by the DPF - Soot (mostly) and Ash (in small amounts)
If the DPF isn't clearing after regens it might be ash rather than soot thats clogging it up. Over time those small amounts of ash collect in the filter and unlike the soot that won't burn off in a regen and eventually there will be too much of it - depending on the make and model 100,000 may well be the expected service life of the filter in that respect. I've just replaced the DPF on my sprinter at 220k but Mercedes reckon on having to replace it every 100k.
If you've ever had the wrong oil (either at a service or as a top up) that can introduce a lot of ash into the DPF too
I was expecting the bill to be pretty eye watering but theres a decent / competitive after-market for DPFs now that lots of models are getting old and rather than the £800 or more for the OEM my replacement was less than £200
That isn’t normal driving though is it.
No but if you are going to "abuse" the car then doing this once in a while will save you more than the lost fuel.
In all likelihood it may even end up saving fuel ...
The EGR fix won’t be cheap
I was pleasantly surprised .... something like £300 (on a BMW E90 3L) at the indy.
OK, £300 is £300 but I'd expected a lot more.
My PD TDI produced no soot out the back when the egr stuck closed, but as soon as it was fixed there was a black/ grey cloud under full load acceleration again. It looks quite surreal at night with head lights refracting through it.
There's always likely to be a light haze under full load, at least in a non-DPF car, I think. Usually visible through the following car's headlights like you say.
New Mot emissions test coming later this month. 20 May.
If Visible smoke, missing DPF etc then it is a major fail.
The rumour is that a major fail means the car can not driven . Must be repaired at mot garage that failed the car. Or scrapped.
anyone know a good vw independent mechanic near Southampton?
I know one on the IoW...
I would have recommended one in Eastleigh, but I've since heard some horror stories.