Turbo Whoosh Noise on decelerating

[DSK]

Originally Posted by sdg1970

I've decided to replace the recirc valve diaphragm too, but I'm having trouble sourcing a new one for some reason. Is it Volvo only part?? Anyone got a link?? 🤔

DO NOT BUY AN IPD ONE! I replaced my OEM Volvo one at a reputable specialist thinking it may be at fault with an IPD one. When they took out the OEM one, it was fine but I asked them to fit the new IPD part now that its out. This split within a few days and IPD's customer service was absolutely disgusting!

I instead fitted a Forge Motorsport unit (bit cheaper than OEM volvo) and its a piston type so will not split.




https://www.forgemotorsport.co.uk/Re...duct--787.html - If you decide on this this, just call them to double check your car and part number)

[sdg1970]

I went Kinuwgawa in the end

[sdg1970]

Here's a quick question - could a split recirc valve diaphragm throw an 0172 code and cause poor idle as well as crap boost etc???

Edited to add: I decided to get the Forge Motorsport valve after all as it seems a no brainer on second thoughts. 🙄

[sdg1970]

Originally Posted by DSK

DO NOT BUY AN IPD ONE! I replaced my OEM Volvo one at a reputable specialist thinking it may be at fault with an IPD one. When they took out the OEM one, it was fine but I asked them to fit the new IPD part now that its out. This split within a few days and IPD's customer service was absolutely disgusting!

I instead fitted a Forge Motorsport unit (bit cheaper than OEM volvo) and its a piston type so will not split.




https://www.forgemotorsport.co.uk/Re...duct--787.html - If you decide on this this, just call them to double check your car and part number)

I fitted one of these, but not sure I fitted it correctly!?! Still got a whoosh and max 7psi. All very odd! Is there a specific way these are fitted? I currently have the vac pipe nipple facing skywards.

[sdg1970]

In conclusion this turned out to be a split throttle body hose, right where the branch comes off to the idle control valve. Massive great big split not visible topside! I replaced all hoses with a D088 kit and it now boosts to max 16psi (unless the dreaded 0172 code appears). I'm sure the Forge Motorsport Diverter valve is helping that figure along nicely...

[DSK]

Thanks for the update, glad you got it sorted.

Would you be able to share a picture of the new hose in place?

[sdg1970]

Originally Posted by DSK

Would you be able to share a picture of the new hose in place?

Is this ok??



I also cleared my 0172 & 0131 codes by fitting a Bosch Ho2s sensor (separate thread)

[byootox]

Originally Posted by sdg1970

Here's a quick question - could a split recirc valve diaphragm throw an 0172 code and cause poor idle as well as crap boost etc???

Edited to add: I decided to get the Forge Motorsport valve after all as it seems a no brainer on second thoughts. 🙄

A split recirc valve diaphragm wouldn't cause any idling issues, but it would cause "crap boost" as the pressure would be just getting recirculated the whole time not allowing the pressure to build up.
Your p0172 code means it's running too rich, the computer will have been trying to trim back the long term fuelling till it couldn't do it anymore then it brings the light on and the fault code appears.
MAFS are common culprit for this, they rarely completely fail but they do go out of calibration gradually.
When they go faulty they can report back too much air or too little, one way makes the car go rich, the other makes it go lean.
A sluggish switching o2 sensor can cause it as well amongst other things.
If you have access to a diag computer, to check live readings this would help a lot.

[sdg1970]

Originally Posted by byootox

A split recirc valve diaphragm wouldn't cause any idling issues, but it would cause "crap boost" as the pressure would be just getting recirculated the whole time not allowing the pressure to build up.
Your p0172 code means it's running too rich, the computer will have been trying to trim back the long term fuelling till it couldn't do it anymore then it brings the light on and the fault code appears.
MAFS are common culprit for this, they rarely completely fail but they do go out of calibration gradually.
When they go faulty they can report back too much air or too little, one way makes the car go rich, the other makes it go lean.
A sluggish switching o2 sensor can cause it as well amongst other things.
If you have access to a diag computer, to check live readings this would help a lot.

Hi Byootox - it's all sorted mate as per the other thread on Beru o2 Sensors. It was a mixture of the p0131 leading to the 0172, due to a bad o2 sensor and a dodgy ECT sensor. All sorted now and this boost/recirc problem was something else entirely...