V70 D5 manual loss of power.
 

Morning folks.
I can’t see it as a sticky so thought I’d ask although I’m sure it’s been asked before.
I have a 2006 D5 manual estate with 90k on the clock, owned for 8 months. Since I’ve had it I occasionally get a repeat ‘engine system service required’ message. It comes on if I give it hard acceleration or perform something like a motorway overtake. The power drops, not dramatically but enough that you have to change your driving style accordingly. The light remains for about 4 subsequent journeys before going out and power feels restored, until driven hard again.
I have learned to drive Roy d the issue as I drive at very quiet times of the day so do t need the power. It’s bloody annoying though and needs fixing.
The car returns excellent t mpg, does 80+ miles a day to work at motorway speed, doesn’t smoke at all, ever, it’s insanely good other than the fault.
I had the codes read (I wasn’t told the code) and was recommended by the mechanic, a friend of a friend to replace the air flow sensor. No difference made. I have replaced the top thick rubber hose from the top of the intercooler which helped a little but it still persists.
It feels like it is being starved of air or similar.
Any suggestions before I start having to Chuck money at it? It’s an old car and not economical to throw loads of cash at it, but it is a bloody good car other than this fault.
Thanks in advance.

Yours is a euro 4 engine, so it’ll have swirl flaps.

Maybe the connecting arm that operates the flaps has fallen off.

have a little read of this

disclaimer Im not a D5 expert at all I just remember seeing the thread recently

I'd look at boost or vacuum leaks. The additional pressure or vacuum when you floor it could be pulling in or forcing open a small split in a pipe which only happens under high engine demand. If yours is a Euro 4 I'd take a good look at the orange seals on the resonator pipe which have a tendency to 'blow open' and re-seat themselves.

HTH

John

I get this on my petrol if I forgot to reconnect the MAF or run the engine without the airbox on (when checking auto box dipstick)

so I would say yes, air leak or MAF

Suspect is often the rubber pipe on the turbo, it goes soft and squishy with age. When affected it can collapse under hard acceleration starving the engine of air and triggering the engine service message.
My experience was on a eu3 engine, not sure if the eu4 had the same squishy pipe, but it’s a quick check down the back of the engine.

Before you do anything else change the fuel filter.

I've had these symptoms twice before and both times it was due to a clogged fuel filter. 24k and 27k between changes in my case. I service my car every 9k but always forget about the fuel filter - not any more!

Both times I had the same symptoms and afterwards had a fully functioning car again, all for £10-15 and half an hour of my time.

BTW I have VIDA (and its invaluable), but it showed all sorts of fault codes (different each time) when the filter change cured all and whilst the fault codes were logged, the limp home went immediately and the car was back to normal.

Hope that helps.

If you fancy a trip to Shrewsbury, I’ll be happy to run a scan on Vida for you.

I had similar symptoms with my S60 when the swirl flap mechanism broke.