help needed with car problem please
Discussion
Hi all - I'd appreciate any suggestions about my car - the local mechanic has tried a few things, but is now at a loss.
It's a 2016 Volvo V40 D2, owned from new and with 109k miles on it now.
In the last few months it started having split second hesitations - like taking your foot off the accelerator. Then power comes back to normal. Usually under light throttle and more likely at lower rpm than higher - like keeping constant speed on the motorway. 30mph in 3rd more likely to do it than 30mph in 2nd.
It also does this hesitation, like it's struggling to pull cleanly through the lower rev range, on getting going from standstill. Again, if I take off with lots of throttle, it's fine. It does this more in the few minutes after a cold start - holding a constant light throttle leads to the car jack-rabbiting. This has worsened in the last couple of weeks.
I've had the fuel filter replaced (just because it had never been done) and run through a few bottles of injector cleaner.
The car has thrown up the check engine light and gone onto reduced engine performance (this hasn't seemed much different to normal performance to me)
Initially the code reader picked up 'insufficient air flow through the GFR valve'. That was taken off and cleaned (it was filthy apparently, but to be expected given age/mileage) to see if we could get away without replacing the valve. That didn't help, so we replaced the valve. Still doing the same though.
The fault codes now are different - still to do with air flow though.
Also, it may or may not be connected but I'm getting 10% worse fuel economy compared to this time in previous years - and the commute and my driving style are unchanged.
I'm thinking about giving it to Volvo to fix - obviously more expensive, but this is very frustrating, I need it fixing and the local garage has admitted he's at a loss. He doesn't think it's an air sensor, as that would usually give it's own fault code. It *may* be the injectors (but he's said it 'could be lots of things'), but he would have to send them away for testing and even then as the fault is intermittent, it may not pick it up. And the injectors are £200 each, without fitting, so just replacing those if not needed would be wasteful. I'm also not *sure* that a Volvo technician would be any better than my local garage mechanic, as he's very experienced and has a good reputation.
Many thanks for any thoughts.
It's a 2016 Volvo V40 D2, owned from new and with 109k miles on it now.
In the last few months it started having split second hesitations - like taking your foot off the accelerator. Then power comes back to normal. Usually under light throttle and more likely at lower rpm than higher - like keeping constant speed on the motorway. 30mph in 3rd more likely to do it than 30mph in 2nd.
It also does this hesitation, like it's struggling to pull cleanly through the lower rev range, on getting going from standstill. Again, if I take off with lots of throttle, it's fine. It does this more in the few minutes after a cold start - holding a constant light throttle leads to the car jack-rabbiting. This has worsened in the last couple of weeks.
I've had the fuel filter replaced (just because it had never been done) and run through a few bottles of injector cleaner.
The car has thrown up the check engine light and gone onto reduced engine performance (this hasn't seemed much different to normal performance to me)
Initially the code reader picked up 'insufficient air flow through the GFR valve'. That was taken off and cleaned (it was filthy apparently, but to be expected given age/mileage) to see if we could get away without replacing the valve. That didn't help, so we replaced the valve. Still doing the same though.
The fault codes now are different - still to do with air flow though.
Also, it may or may not be connected but I'm getting 10% worse fuel economy compared to this time in previous years - and the commute and my driving style are unchanged.
I'm thinking about giving it to Volvo to fix - obviously more expensive, but this is very frustrating, I need it fixing and the local garage has admitted he's at a loss. He doesn't think it's an air sensor, as that would usually give it's own fault code. It *may* be the injectors (but he's said it 'could be lots of things'), but he would have to send them away for testing and even then as the fault is intermittent, it may not pick it up. And the injectors are £200 each, without fitting, so just replacing those if not needed would be wasteful. I'm also not *sure* that a Volvo technician would be any better than my local garage mechanic, as he's very experienced and has a good reputation.
Many thanks for any thoughts.
Just a guess but you say it happens at part throttle, is it at about the throttle setting you use most on your commute? try the throttle position sensor, they do wear and will most likely be worn where they spend most of their time. It may even show up as air flow, as the throttle will be open and sensor saying something else.
May I ask if it is worse when the engine is cold / just warming up?
I had a sticking EGR valve, caused that slight juddering when on a slight throttle and low revs, slightly worse economy.
(Mine failed properly after a 2 hour motorway cruise, gave it an Italian tune up, all cleared)
I vote see about getting the EGR and all associated pipework cleaned, either by replacing, or by one of the many other methods.
I had a sticking EGR valve, caused that slight juddering when on a slight throttle and low revs, slightly worse economy.
(Mine failed properly after a 2 hour motorway cruise, gave it an Italian tune up, all cleared)
I vote see about getting the EGR and all associated pipework cleaned, either by replacing, or by one of the many other methods.
thank you both - i did think about the TPS, but wasn't sure it could cause the airflow problem codes (or change fuel economy) but will ask about this at Volvo next wk (it's in for some recall work on the manifold).
it is worse when cold or just warming up. i tried the Italian tune up myself, but it didn't help
- and the EGR valve was replaced with a new one, after the cleaning out of the original one didn't help. that was a £600 part and only available from Volvo (they told my mechanic they sell loads of them). i will have a look at how to clear out the pipework myself, if i can - thank you
it is worse when cold or just warming up. i tried the Italian tune up myself, but it didn't help
- and the EGR valve was replaced with a new one, after the cleaning out of the original one didn't help. that was a £600 part and only available from Volvo (they told my mechanic they sell loads of them). i will have a look at how to clear out the pipework myself, if i can - thank youI would try and find a proper diagnostic technician. ie people who genuinely are good, experienced and capable of finding faults on modern cars....but they are rare. Very rare.
Main dealers should be up there, but more often than not they're at the lower end of abilities', and the highest end of prices.
Main dealers should be up there, but more often than not they're at the lower end of abilities', and the highest end of prices.
stevieturbo said:
I would try and find a proper diagnostic technician. ie people who genuinely are good, experienced and capable of finding faults on modern cars....but they are rare. Very rare.
Main dealers should be up there, but more often than not they're at the lower end of abilities', and the highest end of prices.
Cheers mate and yes, I’d love to find one, but struggling. It all seems to be moving towards plug it in and replace bits and hope. And I agree with you 100% about main dealers. The prices they charge does not guarantee better ability. Main dealers should be up there, but more often than not they're at the lower end of abilities', and the highest end of prices.
just a closure - and thank you for suggestions. i ended up taking it to the main dealer, as it had recall work that needed doing - i mentioned the issue and they took off and cleaned the pipes going to the EGR unit - and it was fine. they didn't charge me for it either.
i was pleased it was done, but more than a little cheesed off with the local garage - who noted initially the EGV valve was clogged up - so they cleaned that and it was fine for a short while. then a similar read code was thrown up - to do with airflow, but not specifically with the EGR valve. they couldn't ID the problem other than suggesting replacing the EGR unit - at £600 for the part itself. i then told them it was still doing it and the owner didn't know what it could be. went over things like the TPS, as mentioned above - he didn't think it was that, or injectors failing etc.
it was fine until recently when it started doing it very mildly again - so i took it back to the dealer (MOT needed and some further recall work) and they found the pipe was pretty clogged, couldn't clean it, although they tried. so put a new pipe on. £120 - and it's fine. now it's a 6.5 yr old car with 114 miles on it - i've had it from new and do 90 miles a day, 4 days a week, mostly on motorways - so how is it clogging up? they couldn't answer that yesterday
i just hope it doesn't keep happening.
i was pleased it was done, but more than a little cheesed off with the local garage - who noted initially the EGV valve was clogged up - so they cleaned that and it was fine for a short while. then a similar read code was thrown up - to do with airflow, but not specifically with the EGR valve. they couldn't ID the problem other than suggesting replacing the EGR unit - at £600 for the part itself. i then told them it was still doing it and the owner didn't know what it could be. went over things like the TPS, as mentioned above - he didn't think it was that, or injectors failing etc.
it was fine until recently when it started doing it very mildly again - so i took it back to the dealer (MOT needed and some further recall work) and they found the pipe was pretty clogged, couldn't clean it, although they tried. so put a new pipe on. £120 - and it's fine. now it's a 6.5 yr old car with 114 miles on it - i've had it from new and do 90 miles a day, 4 days a week, mostly on motorways - so how is it clogging up? they couldn't answer that yesterday
i just hope it doesn't keep happening. SpydieNut said:
i've had it from new and do 90 miles a day, 4 days a week, mostly on motorways - so how is it clogging up? they couldn't answer that yesterday i just hope it doesn't keep happening.
Emissions control bulls i just hope it doesn't keep happening. 
t, it's just what happens ingesting and recirculating dirty stuffstevieturbo said:
Emissions control bullst, it's just what happens ingesting and recirculating dirty stuff
yup - so i can look forward to doing the same in a few years (hopefully another 6+). can see why some people get the EGR deleted t, it's just what happens ingesting and recirculating dirty stuff
Tony1963 said:
Good to hear it’s sorted.
What fuel do you feed it?
just normal supermarket diesel. would adding in the 'DPF/injector/system cleaner' additives now and again help?What fuel do you feed it?
It's what diesels do. It's what you signed up to when you were tempted by that 50+ mpg. And not helped by running it on the cheapest derv available, either.
And even on your 90 motorway miles per day you're nowhere near what the AA once calculated as the 'break-even' point for running a diesel over a petrol; it was 28,000 miles pa back then (when there was a fuel cost differential), Lord knows how much more it is now... 35,000? By 'break-even' they meant setting your fuel cost savings against extra repair costs, the sort of costs you've just experienced (but which could have been so much more... injectors, turbo, DPF, even DMF... all curses of the modern diesel). And they all rob your wallet eventually. Which is why I dissuade anyone who'll listen from buying one of the filthy things, they're the devil's own work.
Very very few people actually need a diesel in their life. But if you're stuck with one, at least stack the odds in your favour by running it on decent quality fuel (all the time), which will have helpful additives in it.
And even on your 90 motorway miles per day you're nowhere near what the AA once calculated as the 'break-even' point for running a diesel over a petrol; it was 28,000 miles pa back then (when there was a fuel cost differential), Lord knows how much more it is now... 35,000? By 'break-even' they meant setting your fuel cost savings against extra repair costs, the sort of costs you've just experienced (but which could have been so much more... injectors, turbo, DPF, even DMF... all curses of the modern diesel). And they all rob your wallet eventually. Which is why I dissuade anyone who'll listen from buying one of the filthy things, they're the devil's own work.
Very very few people actually need a diesel in their life. But if you're stuck with one, at least stack the odds in your favour by running it on decent quality fuel (all the time), which will have helpful additives in it.
Edited by TwinKam on Friday 9th December 15:59
thank you and yes, fair points. when fuels were about the same price i was very happy doing about 18-20k/yr. no road tax. hopefully diesel will come back towards the price of petrol at some point, but i'm not holding my breath. and it's still doing 57-60mpg average. but then those savings over a modern petrol doing 35-40mpg are easily wiped out by running costs like the ones i've just paid - stuck with it for now though (not just because new cars have such long wait times) so will look at the super diesel option
doing about 18-20k/yr. no road tax. hopefully diesel will come back towards the price of petrol at some point, but i'm not holding my breath. and it's still doing 57-60mpg average. but then those savings over a modern petrol doing 35-40mpg are easily wiped out by running costs like the ones i've just paid - stuck with it for now though (not just because new cars have such long wait times) so will look at the super diesel optionA possible option to help slow down the clogging of the egr valve would be to add a catch can to the crankcase breather pipe.
It won’t stop the exhaust gases but will help reduce the oily vapours that get fed back in to the intake system and ultimately end up mixing with them. It’s those vapours that act like glue, especially when the engine is cold and cause the deposits to build up.
If you fit one, try get one with a fill level tube on the side and monitor it after install so you can judge how often it will need emptying based on your usage.
It won’t stop the exhaust gases but will help reduce the oily vapours that get fed back in to the intake system and ultimately end up mixing with them. It’s those vapours that act like glue, especially when the engine is cold and cause the deposits to build up.
If you fit one, try get one with a fill level tube on the side and monitor it after install so you can judge how often it will need emptying based on your usage.
Glad you got it sorted, don't be too hard on the local guy as it sounds like a bit of an obscure fault with the pipes being blocked instead of the valve itself.
Chances are the guys in the dealer knew exactly where to look as they'd went through the painstaking process of finding the fault originally at some point on that particular model.
Chances are the guys in the dealer knew exactly where to look as they'd went through the painstaking process of finding the fault originally at some point on that particular model.
TwinKam said:
It's what diesels do. It's what you signed up to when you were tempted by that 50+ mpg. And not helped by running it on the cheapest derv available, either.
And even on your 90 motorway miles per day you're nowhere near what the AA once calculated as the 'break-even' point for running a diesel over a petrol; it was 28,000 miles pa back then (when there was a fuel cost differential), Lord knows how much more it is now... 35,000? By 'break-even' they meant setting your fuel cost savings against extra repair costs, the sort of costs you've just experienced (but which could have been so much more... injectors, turbo, DPF, even DMF... all curses of the modern diesel). And they all rob your wallet eventually. Which is why I dissuade anyone who'll listen from buying one of the filthy things, they're the devil's own work.
Very very few people actually need a diesel in their life. But if you're stuck with one, at least stack the odds in your favour by running it on decent quality fuel (all the time), which will have helpful additives in it.
Let's face it, modern diesels with great low rpm torque are great for daily driving and knocking about, and of course towing. And most do use a lot less fuel than an equivalent petrol ( although in current times there is also a much larger disparity between petrol and diesel prices )And even on your 90 motorway miles per day you're nowhere near what the AA once calculated as the 'break-even' point for running a diesel over a petrol; it was 28,000 miles pa back then (when there was a fuel cost differential), Lord knows how much more it is now... 35,000? By 'break-even' they meant setting your fuel cost savings against extra repair costs, the sort of costs you've just experienced (but which could have been so much more... injectors, turbo, DPF, even DMF... all curses of the modern diesel). And they all rob your wallet eventually. Which is why I dissuade anyone who'll listen from buying one of the filthy things, they're the devil's own work.
Very very few people actually need a diesel in their life. But if you're stuck with one, at least stack the odds in your favour by running it on decent quality fuel (all the time), which will have helpful additives in it.
Edited by TwinKam on Friday 9th December 15:59
You simply don't get petrols with an easy 3-400lbft of torque, without them being pretty large engines and relatively thirsty by comparison
But all the emissions bulls
t is very much a curse as you say. But don't forget, modern petrols ,are now seeing DPF's too....so time will tell how much of a disaster they are too.Seems morons in governments are forcing this s
t onto vehicles to make them more unreliable for some reason, and manufacturers are pandering to themstevieturbo said:
SpydieNut said:
i've had it from new and do 90 miles a day, 4 days a week, mostly on motorways - so how is it clogging up? they couldn't answer that yesterday i just hope it doesn't keep happening.
Emissions control bulls i just hope it doesn't keep happening. t, it's just what happens ingesting and recirculating dirty stuffstevieturbo said:
Let's face it, modern diesels with great low rpm torque are great for daily driving and knocking about, and of course towing. And most do use a lot less fuel than an equivalent petrol ( although in current times there is also a much larger disparity between petrol and diesel prices )
You simply don't get petrols with an easy 3-400lbft of torque, without them being pretty large engines and relatively thirsty by comparison
But all the emissions bullst is very much a curse as you say. But don't forget, modern petrols ,are now seeing DPF's too....so time will tell how much of a disaster they are too.
Seems morons in governments are forcing this st onto vehicles to make them more unreliable for some reason, and manufacturers are pandering to them
Particulate filters on petrols should be fine. The particles they produce are a lot smaller than diesel and by design they run a lot hotter making passive regeneration much easier to achieve.You simply don't get petrols with an easy 3-400lbft of torque, without them being pretty large engines and relatively thirsty by comparison
But all the emissions bulls
t is very much a curse as you say. But don't forget, modern petrols ,are now seeing DPF's too....so time will tell how much of a disaster they are too.Seems morons in governments are forcing this s
t onto vehicles to make them more unreliable for some reason, and manufacturers are pandering to themGassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff