D5 AWD- non-smooth manual transmission and delay in power at

[JonnyWatson74]

Hi can anyone help: I have a V70 D5 AWD that is on an 06 plate: my local garage cannot clear a 'high air pressure set too high to turbo' fault code. It's beyond them to fix- they agree with me that the transmission doesn't seem as smooth as expected - in first and second the turbo kicks in very suddenly and the car launches forward more urgently than other diesels I ve driven. There is also a lag at 1800 RPM - almost a stutter before the power kicks in. Previous owner was an older gentleman doing 3k miles a year. Is this a case of dirty injectors? (I ve put forte and redder through it with limited results on this issue) if so what advice, if any does anyone have to address these issues or shall I move the car on .. I know it's very expensive to replace injectors . Thanks all Jonathan

[red baron]

Probably not an overly helpful suggestion but have you tried giving the car a good flooring or driving hard (on a closed road )?

[skyship007]

Originally Posted by JonnyWatson74

Hi can anyone help: I have a V70 D5 AWD that is on an 06 plate: my local garage cannot clear a 'high air pressure set too high to turbo' fault code. It's beyond them to fix- they agree with me that the transmission doesn't seem as smooth as expected - in first and second the turbo kicks in very suddenly and the car launches forward more urgently than other diesels I ve driven. There is also a lag at 1800 RPM - almost a stutter before the power kicks in. Previous owner was an older gentleman doing 3k miles a year. Is this a case of dirty injectors? (I ve put forte and redder through it with limited results on this issue) if so what advice, if any does anyone have to address these issues or shall I move the car on .. I know it's very expensive to replace injectors . Thanks all Jonathan

Be real careful you don't get your wallet felt or your cards played out with the type of faults your engine might have!

Firstly you really must get the hidden fault codes checked by Volvo or some good good Indy that has the correct code reader. Don't pay them for that task unless they print out all the hidden fault codes.
Some of the codes might relate to systems of no real interest due to battery changes or minor issues like a duff glow plug, BUT you must find out if there are any turbo or any fuel injection codes before opening you wallet slightly AND you need to list the exact fault code number, as there are probably several relating to turbo boost.

Never replace injectors before making 100% sure they are not just gummed up. To prevent or clean up gummed up injectors, try using Liqui Moly Diesel Purge every time you replace the fuel filter (Just top it up with Purge). That easy method is a bit wasteful, but the excess direct feed cleaner poured into the filter that finishes up back in the tank does work well as a general diesel additive.
Using Purge is regarded by many German engineers as a standard serice item task. If you use top of the range diesel (Shell, BP or Aral only) then there might be no need to use a direct feed fuel additive.

It would be good if you posted the exact fault code list, as both a defective boost control valve (Easy job) and fuel pressure control valve can cause similar symptoms.

A blocked EGR or real dirty intake might not result in a sensible fault code, but they can cause a big lag when the go pedal is booted, the EGR in particular.

PS: Not sure if the add's you list are direct feed or intake cleaners. Using spray in intake cleaners is very dodgy in a diesel even at idle, although there are a few EGR's that can be cleaned using a specic type of cleaner (They have a long spray hose that positioned to allow the spray into the EGR). Forget what they call that type of cleaner.

Wild guess without fault codes, but it might be an Iffy boost control valve AND a dirty EGR.

I would be careful driving around just in case the turbo starts overboosting, as that can result in something going bang if you are not lucky!

[skyship007]

Originally Posted by red baron

Probably not an overly helpful suggestion but have you tried giving the car a good flooring or driving hard (on a closed road )?

I would not try that until you know what the fault is, as it might do some real damage or result in something nasty like a turbo runaway.

[Clan]

Originally Posted by JonnyWatson74

Hi can anyone help: I have a V70 D5 AWD that is on an 06 plate: my local garage cannot clear a 'high air pressure set too high to turbo' fault code. It's beyond them to fix- they agree with me that the transmission doesn't seem as smooth as expected - in first and second the turbo kicks in very suddenly and the car launches forward more urgently than other diesels I ve driven. There is also a lag at 1800 RPM - almost a stutter before the power kicks in. Previous owner was an older gentleman doing 3k miles a year. Is this a case of dirty injectors? (I ve put forte and redder through it with limited results on this issue) if so what advice, if any does anyone have to address these issues or shall I move the car on .. I know it's very expensive to replace injectors . Thanks all Jonathan

Boost pressure sensors is favourite at the moment , save yourself some money and get a dealer who knows what is what to sort it for you .

[JonnyWatson74]

Originally Posted by Clan

Boost pressure sensors is favourite at the moment , save yourself some money and get a dealer who knows what is what to sort it for you .

You were right- sort of: it was a boost pressure sensor. I also had the actuator refurbished but the car still isnt right. The pressure sensor came up after he engine service management light came on. I had to get it done and it has improved things Big the car still stutters. It has had a replacement EGR a valve before I had it so I suspect the car has always had problems. I ve had the EGR cleaned out when the actuator was done and the car just doesn’t feel right. I suspect it’s a Friday car. I never thought I d have all these issues with a Volvo - and the radio has stopped working! Thanks for advice

[JonnyWatson74]

Originally Posted by skyship007

I would not try that until you know what the fault is, as it might do some real damage or result in something nasty like a turbo runaway.

Just wanted to thank you for your advice - I ended up getting pressure sensor replaced and actuator re furbished but it’s still under or over boosting . I suspect it’s a Friday car - only done 132k but too troublesome.

Thanks again for your detailed advice

PS tried Archoil and Forte diesel
Cleaners made no difference to issue

[davebb]

Hi, as I said in your other post, I would put my money on it being the VNT is not moving correctly, He should have tested that when doing the actuator,
and if your car has a electronic actuator, that is what would have killed the actuator as it will be trying to move the turbo VNT that is stuck with carbon, this is the most common over/underboost as there is no turbo control,
you need to remove the turbo from the car and clean the vnt mechanism,
The so called mechanic taking your cash should know that,
He should have logged the boost then he would have seen it as clear as day,
your recon actuator could be dead now as well,
I would go and get your money back before he books a nice holiday,
Dave