C5 2010 1,6 THP aut. deceleration noise
Moderator: RichardW
C5 2010 1,6 THP aut. deceleration noise
Dears,
Hope you can assist me. As it is stated in the subject I have a 2010 C5 1,6 THP 155 aut.
When I am decelerating from let's say 60 kmh a strange like "blowing" sound comes from the engine. I can only hear it if the windows are down, from inside there is no noise. This sound/noise blowing-rattling sound and it is not the chain tensioner etc because it has been recently changed.
Any ideas what this sound/noise can be, anyone had same issues?
Thank you in advance
Regards,
Lorant
Hope you can assist me. As it is stated in the subject I have a 2010 C5 1,6 THP 155 aut.
When I am decelerating from let's say 60 kmh a strange like "blowing" sound comes from the engine. I can only hear it if the windows are down, from inside there is no noise. This sound/noise blowing-rattling sound and it is not the chain tensioner etc because it has been recently changed.
Any ideas what this sound/noise can be, anyone had same issues?
Thank you in advance
Regards,
Lorant
Last edited by mf.lorant on 29 Oct 2019, 19:22, edited 1 time in total.
- xantia_v6
- Forum Admin Team
- Posts: 9091
- Joined: 09 Nov 2005, 22:03
- Location: France or NewZealand
- Lexia Available: Yes
- My Cars: -
1997 Citroen Xantia V6 (France)
1999 Citroen XM V6 ES9 (France)
2011 Peugeot 308 CC THP 155 (NZ)
1975 Jaguar XJ-S pre-HE (NZ) - x 835
Re: C5 2010 1,6 THP aut. deceleration noise
How long does the noise last?
Does it stop if you gently accelerate?
Does it sound more like an air leak or a whistle or a rattle?
My first guess is that it is a rattling heat shield on the turbo or exhaust.
Does it stop if you gently accelerate?
Does it sound more like an air leak or a whistle or a rattle?
My first guess is that it is a rattling heat shield on the turbo or exhaust.
Re: C5 2010 1,6 THP aut. deceleration noise
Hi,
I can hear the sound when I'm decelerating from let's say 70-50kmh and the noise stops when the rev is lower. The noise is like an air leak sound, not rattling noise.
Do you happen to have a pic of the heat shields? Where should these rattling?
Thx
I can hear the sound when I'm decelerating from let's say 70-50kmh and the noise stops when the rev is lower. The noise is like an air leak sound, not rattling noise.
Do you happen to have a pic of the heat shields? Where should these rattling?
Thx
- xantia_v6
- Forum Admin Team
- Posts: 9091
- Joined: 09 Nov 2005, 22:03
- Location: France or NewZealand
- Lexia Available: Yes
- My Cars: -
1997 Citroen Xantia V6 (France)
1999 Citroen XM V6 ES9 (France)
2011 Peugeot 308 CC THP 155 (NZ)
1975 Jaguar XJ-S pre-HE (NZ) - x 835
Re: C5 2010 1,6 THP aut. deceleration noise
The heat shields around the turbo are immediately visible when you open the bonnet. There are also heat shields above the exhaust behind the engine, on our 308, one of these resonates a little, but only when the engine is cold.
I don't suppose you are noticing the sound to the turbo dump valve? You will hear this as a whooshing sound if you quickly release the accelerator. You can hear it with the car stationary if you have the car in gear with the brakes firmly applied then press the accelerator well down for a second and quickly release it.
The dump valve is much louder if any of the turbo air intake pipes or the crankcase breather pipe are disconnected.
I don't suppose you are noticing the sound to the turbo dump valve? You will hear this as a whooshing sound if you quickly release the accelerator. You can hear it with the car stationary if you have the car in gear with the brakes firmly applied then press the accelerator well down for a second and quickly release it.
The dump valve is much louder if any of the turbo air intake pipes or the crankcase breather pipe are disconnected.
Re: C5 2010 1,6 THP aut. deceleration noise
It is not the heat shields. I did a few testing and those are noiseless. It is an air sound appearing when you decelerate between 70-50 kmh. I just saw that I am repeating myself...
I think it wouldn't be me who is going to solve this, I take it to a mechanic. But still, ideas are highly appreciated
I think it wouldn't be me who is going to solve this, I take it to a mechanic. But still, ideas are highly appreciated
Re: C5 2010 1,6 THP aut. deceleration noise
I have attached a picture of the valve, is this the so called dump valve?
Last edited by mf.lorant on 02 Sep 2018, 22:26, edited 3 times in total.
- xantia_v6
- Forum Admin Team
- Posts: 9091
- Joined: 09 Nov 2005, 22:03
- Location: France or NewZealand
- Lexia Available: Yes
- My Cars: -
1997 Citroen Xantia V6 (France)
1999 Citroen XM V6 ES9 (France)
2011 Peugeot 308 CC THP 155 (NZ)
1975 Jaguar XJ-S pre-HE (NZ) - x 835
Re: C5 2010 1,6 THP aut. deceleration noise
Yes I think that is the dump valve, it opens a passage allowing air from the high pressure side of the turbo back to the inlet of the turbo. Its purpose is to stop the pressure at the turbo outlet getting too high when the throttle is suddenly closed (as happens during gear change with manual transmission). Without the dump valve, the turbo could stall, causing turbo-lag when the throttle is opened again.
Re: C5 2010 1,6 THP aut. deceleration noise
Do you know any other places where air can leak when you decelerate?
Thx
Thx
Re: C5 2010 1,6 THP aut. deceleration noise
Hí,
I have changed the dump valve. It still has the same noise/sound.
The noise seems to come from the front lower left of the car.
Any other ideas?
Thanks, regards
Ps.: I really hope that this sound is not related to the automatic Aisin transmission...I am actually planning to go to a garage having a gearbox oil change
I have changed the dump valve. It still has the same noise/sound.
The noise seems to come from the front lower left of the car.
Any other ideas?
Thanks, regards
Ps.: I really hope that this sound is not related to the automatic Aisin transmission...I am actually planning to go to a garage having a gearbox oil change
Re: C5 2010 1,6 THP aut. deceleration noise
Anyone? No one
- xantia_v6
- Forum Admin Team
- Posts: 9091
- Joined: 09 Nov 2005, 22:03
- Location: France or NewZealand
- Lexia Available: Yes
- My Cars: -
1997 Citroen Xantia V6 (France)
1999 Citroen XM V6 ES9 (France)
2011 Peugeot 308 CC THP 155 (NZ)
1975 Jaguar XJ-S pre-HE (NZ) - x 835
Re: C5 2010 1,6 THP aut. deceleration noise
You need to give some more information.
You said that you would take it to a mechanic. Did you get a diagnosis?
Can you hear the noise with the vehicle stationary when giving the engine wide throttle in gear with the brakes on?
You said that you would take it to a mechanic. Did you get a diagnosis?
Can you hear the noise with the vehicle stationary when giving the engine wide throttle in gear with the brakes on?
Re: C5 2010 1,6 THP aut. deceleration noise
Hi,
I've been to the mechanic, but they did not hear the noise. They tested it in different conditions but nothing, that's what they say.
I tried with the car stationary and wide throttle in gear, but no sound.
So now I am puzzled...
I've been to the mechanic, but they did not hear the noise. They tested it in different conditions but nothing, that's what they say.
I tried with the car stationary and wide throttle in gear, but no sound.
So now I am puzzled...
-
- Donor 2023
- Posts: 13745
- Joined: 01 Apr 2012, 09:47
- Location: Reading
- My Cars: C5 Mk2 VTX+ estate.
- x 3008
Re: C5 2010 1,6 THP aut. deceleration noise
An automotive poltergeist with an audio fetish?
James
ex BX 1.9
ex Xantia 2.0HDi SX
ex Xantia 2.0HDi LX
Ex C5 2.0HDi VTR
Ex C5 2.0HDi VTR
C5 2.2HDi VTX+
Yes, I am paranoid, but am I paranoid ENOUGH?
Out amongst the stars, looking for a world of my own!
ex BX 1.9
ex Xantia 2.0HDi SX
ex Xantia 2.0HDi LX
Ex C5 2.0HDi VTR
Ex C5 2.0HDi VTR
C5 2.2HDi VTX+
Yes, I am paranoid, but am I paranoid ENOUGH?
Out amongst the stars, looking for a world of my own!
Re: C5 2010 1,6 THP aut. deceleration noise
Maybe...
Is there a valve in the automatic transmission which can provide this valve sound when decelerating?
Re: C5 2010 1,6 THP aut. deceleration noise
Again, here is a video of the sound:
I really hope you can hear it, search for a valve sound
I really hope you can hear it, search for a valve sound
Last edited by myglaren on 29 Sep 2018, 15:15, edited 1 time in total.
Reason: YouTube tags
Reason: YouTube tags