V40 T4 4K rpm stutter

Hey all! Great to be talking again! My '02 V40 T4 is requesting your assistance. I know my lambda censor is giving problems, the engine light stays on, but apparently only because the heater on the censor in malfunctioning. Thing is: My car started stuttering about a month ago, but only under extreme acceleration, in third/fourth gear, but you won't feel it it fifth, it is to light a stutter! The whole BIG issue started on Firday, when I was late for a meeting. I drove the car untill it didn't register ANY fuel in the tank, then I could only fill up with 93 unleaded, so I just put about 5 litres in, just to get to another station with 95. When I left with the 93 in my car, all hell broke loose whenever I try to accelerate hard. It stutters as if the timing is out by far!!!! As soon as I lift my foot a centimetre, it's fine, then will go all the way to 5500rpm! I saw a sequence with the stutters starting at just about after 4k rpm, and as far as I know, this is where the vvt cam starts playing?! Anyway, the fuel econo is wonderfull, as I can only drive like grandma, but the car begs a fix, so do I ;) Could this be fuel starfation or the censor? Is it possible the lower budget sparkplugs is starting to come into play, as it's NGK? (hey, it rhimes :)) Thanx for the response, as I can feel it comming :)

In addition to the above invest in a set of genuine Volvo spark plugs, you will see a difference.

Just take it back and see what codes are showing. As for the fuel you will prbably find your octane rating is the same as the US where 95Mon is equal to our 98Ron. Same as your 93 is equal to our 95.

Same issue! 

Hey Telstar I think I have exactly the same issue with my 1999 S40 1.9 T4 Auto. I get a lurching/juddering at about 3500-4000rpm which seems to correct itself when I ease off the throttle a bit. It's deffinately getting worse though as now I have really bad acceleration even in sports mode and have had to drive around in economy mode instead :( Please keep the thread updated as I'd love to know if you get it fixed and what the solution is!

Hi Huskie69, Will do. I am on my way to the Volvo garage, will keep you posted. Funny thing is, as soon as I think it's gone, it happens again!!!

Telstar After I had the spark plugs changed, everything's fine (except for the fuel consumption which I won't go into here!). Perfect acceleration, no loss of power and she goes all the way to 6.5k revs in sports mode before changing gear :D I've yet to try higher octane fuel (I think our premium here is sold by Tesco at 98) as I've read in other forums that higher octane fuel won't make any difference - and it's a lot more expensive here too!