Other XC90 Problem: - Hissing sound on acceleration + Loss of power (Please Help!)

MichaelJode · Aug 15th, 2023, 15:39

This is my first ever post on this website, so please bear with me.....
I have a 2011 XC90 R-Design D5 Engine (with the electronic type Wastegate Actuator).
A couple of days ago, suddenly (and without warning) the engine lost all power on acceleration. It is still possible to build up speed gradually by feathering the pedal, but if you try to accelerate suddenly, its completely unresponsive.
I also noticed that there is a 'Hissing' sound that increases progressively as the revs increase, and then releases, much like the sound of a 'Dump Valve' on a modified petrol turbo, only this sound is much quieter.
The wastegate actuator and lever arm all appear to be operating smoothly, and there are no visible signs of sooty 'gas leakage' in the area surrounding the turbo (although...I haven't attempted to remove the heat shield from the exhaust manifold yet). The hissing sound is really difficult to pinpoint, but is almost certainly coming from the area around the top of the CAT/manifold or turbo. Has anyone else experienced this problem and/or know what the fault maybe?
BTW...in the process of fault-tracing, I've stripped and thoroughly cleaned my heavily-clogged EGR and associated hoses/chambers, and removed the corrugated steel pipe (from beneath the vacuum pump) to check that is not fractured in any way.

DickyB V70R · Aug 15th, 2023, 16:59

My money is on a Boost Leak on the Resinater Pipe to the Turbo...

There are 2 Orange Rubber Seals on it that can and do split over time.
Quite a common problem.

MichaelJode · Aug 16th, 2023, 00:59

Thanks very much for the quick reply. I won't know for sure until I strip it down tomorrow, but I've got a very good feeling that you're spot-on with your diagnosis, it would certainly explain the noise I'm hearing.
I appreciate you taking the time to reply!

Cloth Ears · Aug 16th, 2023, 12:06

Not Volvo, but on my old Audi I had a leaky pipe from the intercooler which was audible. It caused a turbo overspeed, I suspect, which killed the turbo soon after, so might be worth checking those too.

DickyB V70R · Aug 26th, 2023, 09:34

Quote:

Originally Posted by MichaelJode

Thanks very much for the quick reply. I won't know for sure until I strip it down tomorrow, but I've got a very good feeling that you're spot-on with your diagnosis, it would certainly explain the noise I'm hearing.
I appreciate you taking the time to reply!

How did you get on with this Michael...? Hope you got it sorted.

Aug 15th, 2023, 15:39	#1
MichaelJode New Member Last Online: Aug 16th, 2023 00:59 Join Date: Aug 2020 Location: Corringham	Hissing sound on acceleration + Loss of power (Please Help!) This is my first ever post on this website, so please bear with me..... I have a 2011 XC90 R-Design D5 Engine (with the electronic type Wastegate Actuator). A couple of days ago, suddenly (and without warning) the engine lost all power on acceleration. It is still possible to build up speed gradually by feathering the pedal, but if you try to accelerate suddenly, its completely unresponsive. I also noticed that there is a 'Hissing' sound that increases progressively as the revs increase, and then releases, much like the sound of a 'Dump Valve' on a modified petrol turbo, only this sound is much quieter. The wastegate actuator and lever arm all appear to be operating smoothly, and there are no visible signs of sooty 'gas leakage' in the area surrounding the turbo (although...I haven't attempted to remove the heat shield from the exhaust manifold yet). The hissing sound is really difficult to pinpoint, but is almost certainly coming from the area around the top of the CAT/manifold or turbo. Has anyone else experienced this problem and/or know what the fault maybe? BTW...in the process of fault-tracing, I've stripped and thoroughly cleaned my heavily-clogged EGR and associated hoses/chambers, and removed the corrugated steel pipe (from beneath the vacuum pump) to check that is not fractured in any way.

Aug 15th, 2023, 16:59	#2
DickyB V70R Senior Member Last Online: Yesterday 12:03 Join Date: May 2006 Location: Suffolk	My money is on a Boost Leak on the Resinater Pipe to the Turbo... There are 2 Orange Rubber Seals on it that can and do split over time. Quite a common problem. __________________ Saffy V70R Auto...Gone But Not Forgotten. Now got...Silver P2 04-05 V70 D5 (Facelift). 09 XC90 R-Design (the Barge).

Aug 16th, 2023, 00:59	#3
MichaelJode New Member Last Online: Aug 16th, 2023 00:59 Join Date: Aug 2020 Location: Corringham	Thanks very much for the quick reply. I won't know for sure until I strip it down tomorrow, but I've got a very good feeling that you're spot-on with your diagnosis, it would certainly explain the noise I'm hearing. I appreciate you taking the time to reply!

Aug 16th, 2023, 12:06	#4
Cloth Ears Member Last Online: Apr 25th, 2024 14:35 Join Date: Aug 2021 Location: Manchester	Not Volvo, but on my old Audi I had a leaky pipe from the intercooler which was audible. It caused a turbo overspeed, I suspect, which killed the turbo soon after, so might be worth checking those too.

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