[blippybay]

I've recently bought a late 2015 Mazda 6 2.2d Skyactiv. The car has 79k miles on with good service history. At 60k it had a new Turbo and at 64k it had a full carbon clean at the main dealers

So far I've done about 600 miles in it, a mix of motorway (a couple of long trips, 120 miles each way) and town driving.

Today I assume it did a regen, istop to not ready and halo around the engine symbol not lit. However during the regen the car ran very badly, really down on power (wouldn't accelerate over 70mph) and was like it was misfiring, you could feel the engine stuttering under any real load, partial throttle with no load it was OK, and revved fine stationary. After 15 mins of driving, the istop went back to ready and the halo reappeared around the engine symbol car seemed to run fine again.

Is this normal when regenerating the DPF, or is it a sign of another issue? I've had Diesel VW and Audis before this, of a similar age and newer, I'd never even notice they were doing regens. And if it is normal, I'm not sure I can stand it doing this every few hundred miles, it was awful to drive for those 15mins or so.

 

[blippybay]

Little update, it started doing it again today, same thing, under heavy acceleration (joining a motorway) the car was stuttering, like it was misfiring slightly. It definitely wasn't regenerating this time.

I noticed if I turn the car off and leave it a few minutes, then restart it, the stuttering goes away.

The car is on 79k, at 60k it had a new Turbo, and at 64k it's had a Full carbon clean by Mazda.

 

[Benedict]

Your correct, there is no change to the car during a regen, unles you look at instantanous fuel consumption and it drops to 30mpg.
Stuttering I would tend to look at fuel quality. Water in fuel, fuel filter may require changing.
If you remove your battery you will see the fuel filter and at the bottom there is a drain valve (white nylon), attach a pièce of tube to it and run some fuèl into a clean jam jar say about half full. Let it stand a few hours to see if it separates.

You may not know when the fuel filter was changed, but check the invoices, see if a fuel filter was ever fitted.
Could be a bit of dodgy fuel, considering all this rain we have had. Have yòu driven through any water and an electrical connection has got splashed.
Never heard of that problem in 8 years on Mazda 6 forums.
Presumably your fuel tank is above 1/4 full and you are not running on fumes. Not put petrol in by any chance, it will still run as long as there isn't too much.
I am just pulĺng at straws.
If all eĺse fails you need to take it in, but let the forum know what was the cause.

 

[blippybay]

Your correct, there is no change to the car during a regen, unles you look at instantanous fuel consumption and it drops to 30mpg.



Stuttering I would tend to look at fuel quality. Water in fuel, fuel filter may require changing.



If you remove your battery you will see the fuel filter and at the bottom there is a drain valve (white nylon), attach a pièce of tube to it and run some fuèl into a clean jam jar say about half full. Let it stand a few hours to see if it separates.



You may not know when the fuel filter was changed, but check the invoices, see if a fuel filter was ever fitted.



Could be a bit of dodgy fuel, considering all this rain we have had. Have yòu driven through any water and an electrical connection has got splashed.



Never heard of that problem in 8 years on Mazda 6 forums.



Presumably your fuel tank is above 1/4 full and you are not running on fumes. Not put petrol in by any chance, it will still run as long as there isn't too much.



I am just pulĺng at straws.



If all eĺse fails you need to take it in, but let the forum know what was the cause.

Thanks. I fitted a new fuel filter, didn't help. Generally it can be driven and as long as the cars moving it's OK. As soon as it sits in traffic any length of time, the car is juddering and stuttering badly, it struggles to idle and is undriveable. Park it for a while runs perfectly again until the next time.

The Main Dealer thinks it needs new injectors.

 

[Benedict]

New injectors are going to cost you £3-4k, so the 'Dealer thinks' needs to be a bit more positive. It either does or doesn't and he needs to base his guesswork on fact and physical proof and tests.
Before forking out that sort of money the injectors could be removed and taken to a fuel injection specialists and put on one of the new machines to test Common rail injectors to prove if they are faulty and I would if I was you witness the testing.
You could call round to a Bosch agent and ask if he can test this type of injector as you need a special rig for these.
If you live anywhere near Reading there is a place there south of the M4.

Peter Strong Diesel Fuel Injection
Ì have spoken to him but never gone round.
Or if you are in the North there is Feathers .