Engine stutter D4 AWD 2016 manual

[Kieranwhite9]

Help! My Xc60 occasionally has a stutter under normal driving. Generally in high gear and not under load. Revs are between 2- 4000rpm. Speed is 30 - 40 mph although it has done it at higher speed. Volvo can't find a fault. They've checked everything, apparently. It never does it under acceleration, but when the accelerator is lightly pressed under normal driving conditions/speed, it will lose power/ stutter as if it's starved of fuel or something. It's intermittent and is one of those faults which doesn't always happen. I could drive for two or three days without any problems. Today it did a massive stutter/jolt before it carried on as normal. I was doing 35mph in 4th gear when it happened. It's driving me crazy and I know Volvo will just plug it in, not find a fault. Test drive it and it will be fine and give it back without any fault being found. It has had the ecu recall and all updates have been carried out. Can anyone give me any ideas as what might cause a loss of power/stutter/jolt for half a second on an intermittent basis? My wife drove it to Devon and at 70mph in 6th gear it was doing it lots but coming back it was fine! Thanks for your help.

[wilbydoughboy]

It also reads to me like some form of fuel delivery problem. Keep a note of the fuel level when you notice the stutter start, it could be happening when the fuel gets to a certain level. I had a very similar problem with a Suzuki van and it was when the fuel got to a certain level. I had to find the problem for the dealer before they could repair it, I think it was the sender in the fuel tank playing up. Often there are people on this forum who can give some clues.

[Kieranwhite9]

Thanks. I hope so! I will keep an eye on the fuel level when these stutters happen. It's got to be something to do with the fuel delivery though, not being a mechanic I wouldn't have a clue. Because they couldn't replicate the fault, as far as Volvo were concerned there was nothing wrong!?

[xzzz9097]

I experienced the very same problem on my D4 AWD MY2015 (should be the same engine, I also had manual transmission like you) past summer and I know how frustrating it can be, especially in the city traffic with the car bouncing around at every restart. In my case dealer changed the Lambda sensor as it was really dirty. But probably the most effective thing I did on my own was resetting ECU driving style data: it's very simple, just turn on the dash by pressing the start button without clutch (therefore the engine stays off), then press full throttle for 30 seconds. Then I've done some weeks of spirited driving (changing gear a bit later, pressing throttle a bit more) to "imprint" the ECU. In about a month stutters were gone and, after a year, everything is good. My theory is that, since I'm very "light-footed", the ECU adopted an excessively lean fuel mix that made the engine stutter on certain occasions, and resetting it helped a lot.
Hope it'll be the same for you!
By the way, in the same period I had the infamous rising oil issue (yes, on a MY2015, so it's not really solved), it was just going up like crazy every week. What about yours? You can check it from the dash, too. I think it was related to driving style as well, since it went away with the stutters after I started driving a bit harder.

[wimorrison]

Do you get any message to say that the ECU has been reset or are you assuming it has reset?

[Agouti]

Lambda sensor in a diesel? Never heard of that before.

If it was a fuel delivery issue you would expect it to be a bigger problem under heavy load, not light throttle. Some speculation as I don't know how the new ones work:

A problematic throttle position sensor could do it if it had a rough spot.

It could be turbo related, surging just as it starts to make positive boost. I believe the new D4 is still single turbo so no sequential switchover malarkey.

It might only be doing it during an active DPF regeneration cycle, when it is turning on or off the exhaust diesel injection based on exhaust gas temps (directly related to throttle). Check your mpg, especially coasting at idle in a gear that holds the RPM up a bit. If it is regenerating you won't be able to get near infinite MPG when coasting.

Something in the system that adds throttle when the air conditioning compressor cycles on? Wasit warm outside when it last did it?

[Kieranwhite9]

xzzz9097, i will definately give that a go. Iv'e never heard of being able to do that. Hopefully it will cure the stutter.

Agouti, Funnily enough, i think it does do it when the weather is hotter outside and the aircon is on? I will keep that in mind when it next happens.

BTW, my averahe MPG is 34MPG? That is pretty bad is it not??

Thanks for all your advice. I will let you know how this develops.

[wimorrison]

I think you will find it was the 'spirited driving' that improved the issue rather than the claimed 'ECU reset', but I guess as it doesn't cost anything other than 30s of your time then nothing will be lost trying it.

[Fursty Ferret]

Change the turbo vacuum hose as discussed elsewhere on this forum.

[xzzz9097]

Originally Posted by Kieranwhite9

xzzz9097, i will definately give that a go. Iv'e never heard of being able to do that. Hopefully it will cure the stutter.

Agouti, Funnily enough, i think it does do it when the weather is hotter outside and the aircon is on? I will keep that in mind when it next happens.

BTW, my averahe MPG is 34MPG? That is pretty bad is it not??

Thanks for all your advice. I will let you know how this develops.

I can confirm it was worse with hot weather (I experienced it between 1k and 2k rpm with light throttle), that prompts me to think it's the same problem.

Regarding my supposed mechanical fix, I also thought there were no Lambda sensors in Diesel engines, but apparently there are several O2 sensors on the exhaust chain (pre and post DPF) that the ECU uses to adjust combustion parameters. They said one of them was dirty and replaced it, though the problem did not solve immediately so I'm not sure that was the root cause.

Around september I tried ECU reset and changed my driving style and after about two week the stutter was gone. Maybe that was also because of colder weather? Fact is the car did not stutter ever since, even this summer with 30+ °C. I'm averaging 42mpg mostly on 55mph b-roads, but I do very few city driving.

Anyway, there were no other mechanical damages. I strongly suggest you checking the oil level though, as I had it really high in that period and it can cause severe issues to the engine (it is diluted with diesel).