Hi, for a few years now I got a bit of a problem with my car. As I dont do very long trips with my car as I use it to commute to work (15 miles one way), sometimes my DPF regen starts just before I arrive to work. Well obviously I cant just drive around so I have to switch the engine off during an active DPF regen. But what happens is that when I start the engine after a while, the active DPF regen carries on after a minute or so, while the engine is cold. This results in a shaky engine, nasty smell and quite a lot of white smoke while the engine is not up to the operational temperature. Is that possible that the active DPF regen won't stop until it actually finishes itself, even tho I switched the engine off inbetween? Went to 3 different garages, all told me that they can't see anything on the diagnostics and the one thing they told me to never interrupt the active DPF regen. But everything I read so far it said that when you switch the engine off durin a regen it will stop it and will start to do it all again at some point again, not carrying when it left of.  My engine is a 2010 1.6 Tdi. Thank you for any help I can get.

It wont stop until the % of soot in the DPF goes bellow a set level. It will keep regening until it is happy. Do you give it a good run after work when its on regen or just drive 15 miles and turn off. If so that wont help.

 

Shaky engine is normal for regen, mine does this when its on a hard regen, nasty smell is also normal but usually only when the cars really clogged up. A garage should be able to check the % of the DPF and see how clogged up it is but tbf it just sounds like it needs a good drive as 15 miles isnt good for that diesel. Especially if its not on a motorway. 

 

Give it a good 30+ drive at constant 70mph (easier at night) for around 30 motorway miles. Let it get up to temp and give it some. Drive it like you stole it, these cars like to be beat on every now and again to get the oil temp up.

 

 

Stopping the engine during a regen shouldn't cause a problem.  I do it frequently.  What is NOT right is that you are getting the shaking and white smoke on restart.  After an interruption my 65k mile old 1.6TDi doesn't restart the process until the engine is warm - after 4 or 5 miles,  I never get any smoke and the engine never shakes.

The signs I get when a regen is in progress are:

• tickover rises to 1000rpm
• oil temperature (maxidot) climbs very quickly to 10-20 degrees above where it is in normal running
• a change in engine note on gentle acceleration - sounds a little as though the exhaust is blowing across the top of a bottle
• the exhaust smells like the smell of burning aviation fuel you get around airports
• there is a smell of hot rubber, only noticeable if you get out of the car immediately after interrupting the regen. 
• very occasionally, the cooling fan runs on after the engine has stopped and key removed.

On 20/01/2020 at 17:57, JGrindel said:

It wont stop until the % of soot in the DPF goes bellow a set level. It will keep regening until it is happy. Do you give it a good run after work when its on regen or just drive 15 miles and turn off. If so that wont help.

 

Shaky engine is normal for regen, mine does this when its on a hard regen, nasty smell is also normal but usually only when the cars really clogged up. A garage should be able to check the % of the DPF and see how clogged up it is but tbf it just sounds like it needs a good drive as 15 miles isnt good for that diesel. Especially if its not on a motorway. 

 

Give it a good 30+ drive at constant 70mph (easier at night) for around 30 motorway miles. Let it get up to temp and give it some. Drive it like you stole it, these cars like to be beat on every now and again to get the oil temp up.

 

 

Or use a lower gear, to avoid points and fines...diesel engines are always more happy under load and run cleaner at higher revs.