V50 2.0D jolting at constant speed

Rolymoley · Jul 28th, 2015, 20:54

Volvo V50 2.0 Diesel
i have an intermittent fault where the car will judder and jolt enough that i notice it but cant be seen through the rev counter. it only happens during a constant throttle position roughly 1/4 , 1/3 of the way down. no throttle and full throttle are fine, it is just when i am trying to maintain a constant speed. the jolting is worse in 2nd and 3rd gears usually. there has also been a drop in power after the jolting in some cases.

some trips the car is perfect and some i dont want to drive it at all. it is a really annoying fault and i want it fixed.
the car has been to a local garage 3 times. 1st the only fault code was related to the turbo boost pipes so i replaced them with genuine volvo pipes. 2nd was a cracked flexi pipe on the exhaust which got replaced. 3rd was an air temperature sensor in the throttle housing which got replaced. the car was ok for a couple of days but the fault came back.

i took the car to a main dealer where they found DPF fault codes (which was my first thought to the cause) so they topped the fluid and forced a regeneration. the car was ook for a couple of days but the fault came back. the car went back and more DPF codes were found so they replaced it and the old one was blocked. but still the fault is there.

I am running out of ideas and money and want to know what else i can try to save me some money. all i have to try that might work is the fuel filter.
any help is apreciated!!
Ross

V50D · Aug 6th, 2016, 20:09

If it was a fuel filter (fuel starvation) wouldn't in also manifest its self at increased throttle?

As you know from our discussions I also have the same or at least similar issue, and forum searches do indicate other so as well.

Interesting you metion throttle position, for my it is more a specific rev bad. 1500 to about 2200rpm. But it is noticeable if you cruise in this rev band (ie just keep constant throttle). Like you, if I push through it by accelerating you can quite quickly get past it. I just don't want to cruise everywhere a 3k revs!

I wonder if theses cars have some sort of throttle position sensor?

Today I cleaned the intake into the throttle body and it was quite filthy inside. I also put a can of diesel EGR cleaner through the whole engine (via the air intake). I'm sure it has helped but not cured the problem. I'm thinking there may be an air leak... I know for sure I'm getting exhaust gas escaping at the back of the engine, and a low turbo pressure warning. Whether they are related is another matter!

5cilinder · Aug 12th, 2016, 05:33

Extra or less air dont have much impact on diesel combustion because it burns already under large air excess (particulary at part load)
The jolting will be a result in fuel output variation

Try a few second hand gaspedals , i experienced a lot of different throttle reactions no one was the same!
I was able to test a few at the breakers to pick the best one

lez · May 26th, 2017, 10:43

Hi,

Did you managed to resolve the issue?

Jul 28th, 2015, 20:54	#1
Rolymoley Volvo V50 2.0D 2005 Last Online: Aug 4th, 2016 17:21 Join Date: Jul 2015 Location: shropshire	V50 2.0D jolting at constant speed Volvo V50 2.0 Diesel i have an intermittent fault where the car will judder and jolt enough that i notice it but cant be seen through the rev counter. it only happens during a constant throttle position roughly 1/4 , 1/3 of the way down. no throttle and full throttle are fine, it is just when i am trying to maintain a constant speed. the jolting is worse in 2nd and 3rd gears usually. there has also been a drop in power after the jolting in some cases. some trips the car is perfect and some i dont want to drive it at all. it is a really annoying fault and i want it fixed. the car has been to a local garage 3 times. 1st the only fault code was related to the turbo boost pipes so i replaced them with genuine volvo pipes. 2nd was a cracked flexi pipe on the exhaust which got replaced. 3rd was an air temperature sensor in the throttle housing which got replaced. the car was ok for a couple of days but the fault came back. i took the car to a main dealer where they found DPF fault codes (which was my first thought to the cause) so they topped the fluid and forced a regeneration. the car was ook for a couple of days but the fault came back. the car went back and more DPF codes were found so they replaced it and the old one was blocked. but still the fault is there. I am running out of ideas and money and want to know what else i can try to save me some money. all i have to try that might work is the fuel filter. any help is apreciated!! Ross

Aug 12th, 2016, 05:33	#3
5cilinder Premier Member Last Online: Yesterday 21:40 Join Date: Oct 2011 Location: Groningen	Extra or less air dont have much impact on diesel combustion because it burns already under large air excess (particulary at part load) The jolting will be a result in fuel output variation Try a few second hand gaspedals , i experienced a lot of different throttle reactions no one was the same! I was able to test a few at the breakers to pick the best one Last edited by 5cilinder; Aug 12th, 2016 at 06:19.

Aug 6th, 2016, 20:09	#2
V50D Junior Member Last Online: Aug 21st, 2016 22:13 Join Date: Jul 2016 Location: Ely	If it was a fuel filter (fuel starvation) wouldn't in also manifest its self at increased throttle? As you know from our discussions I also have the same or at least similar issue, and forum searches do indicate other so as well. Interesting you metion throttle position, for my it is more a specific rev bad. 1500 to about 2200rpm. But it is noticeable if you cruise in this rev band (ie just keep constant throttle). Like you, if I push through it by accelerating you can quite quickly get past it. I just don't want to cruise everywhere a 3k revs! I wonder if theses cars have some sort of throttle position sensor? Today I cleaned the intake into the throttle body and it was quite filthy inside. I also put a can of diesel EGR cleaner through the whole engine (via the air intake). I'm sure it has helped but not cured the problem. I'm thinking there may be an air leak... I know for sure I'm getting exhaust gas escaping at the back of the engine, and a low turbo pressure warning. Whether they are related is another matter!

May 26th, 2017, 10:43	#4
lez New Member Last Online: May 25th, 2018 16:33 Join Date: Mar 2017 Location: Portsmouth	Hi, Did you managed to resolve the issue?

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