Help Please Audi A4 B8.5 2.0 TDI - Regen interrupted?

[777GE90]

I've had my B8.5 for a couple months now and it's my first diesel car, yesterday I jumped out of the car only to be smacked in the face with a whoosh of hot air and I noticed the vehicle fan was still on even though the engine was off, I had only driven around 5 miles (doing shopping run) so I was surprised the engine was so hot.

Then it dawned on me, the car was attempting a regen, so I got the shopping in the house and quickly jumped back in the car and blasted off to the motorway, kept it between 2000 to 3000 rpm for about 15 miles, bought it back, parked up and got out, no heat anymore and the fan went off as soon as I turned off the engine. So I'm not sure if the regeneration happened / resumed and finished on the motorway or whether it just stopped and interrupted as soon as I shut the engine the first time?

Can anyone shed any light as I am keen to avoid a blocked DPF, it's just unfortunate timing for it to choose regeneration when I'm doing the weekly shopping . Did I do the right thing to take it on the motorway or was that unnecessary?

 

[Mario]

To be honest I wouldn't worry about it too much, as long as the car gets regular runs where it can do a regen it's not going to get blocked because you turned it off in the middle of 1 or 2, it will just re-start the regen process next time it gets a chance. Obviously if you keep doing really short journeys and not allowing it to regen that's where you will end up with issues, but I wouldn't worry about it happening on the odd occasion.

Just enjoy the car and forget about it. DPF's are not as fragile as the media would have you believe, and the Audi ones are some of the better ones that don't block as easily as the ones you see in Nissans, etc.

 

[777GE90]

To be honest I wouldn't worry about it too much, as long as the car gets regular runs where it can do a regen it's not going to get blocked because you turned it off in the middle of 1 or 2, it will just re-start the regen process next time it gets a chance. Obviously if you keep doing really short journeys and not allowing it to regen that's where you will end up with issues, but I wouldn't worry about it happening on the odd occasion.

Just enjoy the car and forget about it. DPF's are not as fragile as the media would have you believe, and the Audi ones are some of the better ones that don't block as easily as the ones you see in Nissans, etc.

Hm ok, but how do I know when it will try again? How long will it need? Is there a way I can force it to try again when I'm driving longer distances?

 

[IRONy_MAN]

Hey no need to worry I ve stopped the car two times in a middle of regen obviously in emergency situations so I ve had no choice and the car went (even after one hour )straight into regen so no probs in here I ve seen silly opinions like if you stop it straight away you get problems but as long as happens just one in a wile should be fine. Adi

 

[Mario]

1. how do I know when it will try again?
2. How long will it need?
3. Is there a way I can force it to try again when I'm driving longer distances?

1. You don't know when it will try again, the car has 2 forms of regen....Passive and Active. Passive occurs with normal driving, the car does nothing and the natural heat of the engines exhaust gasses keep the DPF clean. Active occurs when the Passive regen is not enough, so the cars ECU adds more fuel and adjust the timing to ensure that a lot more heat is generated on the exhaust stroke to help clean the DPF.

You have ZERO control over these, there is nothing you can do to manipulate them.

2. Regen takes 15 - 30 minutes, but I would NEVER drive past my destination or take an extra long route just to let the car finish a regen, it can always complete the regen later on.

Think about it this way. Imagine the DPF is 50% blocked and the car starts an Active regen and then you turn it off when it gets down to 30%, you have still cleared 20% of the soot and it can continue the job next time you drive it.

3. Nope, you cannot control the Active regens without VCDS or a Dealer tool to do a forced regen which should ONLY be done if you have DPF problems. The only influence you have is how you drive it, keeping in a low gear with high revs will help clean up the DPF, but then you lose your MPG, so why did you even bother buying a diesel?

I do 10 miles to work and back each day with 80% of that being 30mph town roads and the other 20% is only 40 MPH & 50 MPH single & dual carriage ways. Yet the only time I have had the DPF light on is when the EGR valve broke. Since replacing the EGR the DPF light has never come back, that was last April.

Just drive the car and enjoy it. Don't over think this whole DPF regen thing.

 

[777GE90]

1. You don't know when it will try again, the car has 2 forms of regen....Passive and Active. Passive occurs with normal driving, the car does nothing and the natural heat of the engines exhaust gasses keep the DPF clean. Active occurs when the Passive regen is not enough, so the cars ECU adds more fuel and adjust the timing to ensure that a lot more heat is generated on the exhaust stroke to help clean the DPF.

You have ZERO control over these, there is nothing you can do to manipulate them.

2. Regen takes 15 - 30 minutes, but I would NEVER drive past my destination or take an extra long route just to let the car finish a regen, it can always complete the regen later on.

Think about it this way. Imagine the DPF is 50% blocked and the car starts an Active regen and then you turn it off when it gets down to 30%, you have still cleared 20% of the soot and it can continue the job next time you drive it.

3. Nope, you cannot control the Active regens without VCDS or a Dealer tool to do a forced regen which should ONLY be done if you have DPF problems. The only influence you have is how you drive it, keeping in a low gear with high revs will help clean up the DPF, but then you lose your MPG, so why did you even bother buying a diesel?

I do 10 miles to work and back each day with 80% of that being 30mph town roads and the other 20% is only 40 MPH & 50 MPH single & dual carriage ways. Yet the only time I have had the DPF light on is when the EGR valve broke. Since replacing the EGR the DPF light has never come back, that was last April.

Just drive the car and enjoy it. Don't over think this whole DPF regen thing.

Thanks that clears up a lot. I actually used to do 500 miles a week in my old Polo, now that I've upgraded to the A4 my circumstances have changed and now I do more like 50 miles a week and will probably remain that way for this year anyway. I didn't buy diesel for MPG to be honest, I didn't really care about that. I only bought Diesel as I'm only 23 and if I got a TFSI A4 my insurance would charge me an arm and a leg (due to the extra BHP) so I was forced to buy the diesel. I was well aware of DPF issues before I made the purchase and usually do extra trips on the motorway's and stick in lower gears to give it extra heat time but was just curious on the best way to take care of it considering I ain't constantly driving it long distance anymore.