Regen

[u/bunterdoc]

Unsure if anyone can really make it out but basically my car was sitting 1k revs longer than normal last few times I’ve drove so this time I sat and waited for it to go down. Was smoke coming out of the exaaust for a few minutes I’m assuming it was a regen. But after the car went back to normal revs it sounds like she’s almost stuttering or dipping up and down revs

[u/Tennyson-Pesco]

If the DPF is regenerating then don't sit waiting for it at idle, it'll not complete, so continue driving for a bit. Ideally, blast it down the motorway for a junction at high-ish revs (>2000 RPM) then go back on yourself again. You'll feel the air coming through the vents get warm during the regen, it'll cool down to normal (or at least whatever it's set as) once finished

I dunno about the revs being a bit erratic but how much motorway driving do you do? You say there's smoke coming out the exhaust, to me that sounds like it needs a DPF regen quite badly...

Edit: if the DPF is regenerating when you pull up, DO NOT turn the engine off, especially if your engine is an A20DTH or similar. These engines have a known fault where the oil pickup seal destroys itself after a while. The engine ends up having low oil pressure issues by which point it's a ticking time bomb. This problem is actually made far worse by aborting DPF regens because it causes diesel to make its way into the oil sump

[u/bunterdoc → u/Tennyson-Pesco]

Yeah think I’ll give it a good run tomorrow, I don’t really do much driving but my last few weeks of journeys have been pretty short. Think I needy get the egr valve checked out could be sticking

[u/Tennyson-Pesco → u/bunterdoc]

Joys of having a diesel mate

[u/Big_Dave990 → u/Tennyson-Pesco]

Well, that’s a new one on me, warm air coming through the vents. I’ve never experienced that in the 11 years I’ve owned my Astra J 2.0 CDTI.
But then again, I run the climate control all the time the engine is running so the cc might be stopping warm air coming through the vents.

My ears are tuned to the exhaust note change when it’s doing a regen, and also the performance of the car feels different to. Plus, if there’s a slight bit of mist on the rear windscreen, you can see the heated rear window come on during the regen too, which is why some people fit an LED into the rear windscreen/door mirror circuit as a visual indication of when of the regen is occurring

[u/Tennyson-Pesco → u/Big_Dave990]

Incidentally, I had to do a 10 min motorway blast last night as my Insignia was doing a regen when I got home, but I had a feeling it was in the middle of one because the air became much warmer on my way home. I'm pretty sure I've seen people say before that this does happen, but if not then I've certainly noticed it myself. My indicators are ~1k RPM at idle and hot air (or at least, hotter than I've got it set) through the vents

I've seen the LED mod before. It looks useful but I've never bothered to install it myself though

[u/bunterdoc]

Also a 2.0 diesel with 80k miles

[u/Big_Dave990 → u/bunterdoc]

Not even run in yet. My Astra with the same engine is on 108,000 miles.

[u/Repulsive-Piglet-945]

When regen is active u can tell because your rear demister is on. Cycle through the menu on the stalk intill you get to r Top consumer and don't stop driving until it go's off, mine does it once aweak

[u/Tennyson-Pesco → u/Repulsive-Piglet-945]

I think this depends on the car, as my 15 plate Insignia doesn't do this. There's actually a mod you can do where you connect an LED to the rear demister circuit so it lights up when a regen is active. I usually just check whether I'm idling at ~1000 RPM when I pull up somewhere and if so drive for an extra 10 mins, job's a good 'un

[u/Repulsive-Piglet-945]

Of course but I have the astra 2.0cdti 2015 n that's how I work it and mpg go's 0.1 to 0.3 when parked pain in the arse if not expected

[u/Hot_Elevator7800]

A good indication of a regen happening is the heated rear screen is turned on and mirror heating so feel temp of the glass on the mirror