moaning noise after run

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
bill hughes
Posts: 229
Joined: 30 Jan 2013, 13:22
Location: West Sussex
My Cars: 1994 xantia 1.9 tdi sold on and still going strong 2ooo xantia 2.0hdi estate 1998 Renault megane 1.4
x 2

moaning noise after run

Post by bill hughes »

Hi I have a1994 xantia 1.9 td and sometimes it makes a strange moaning sound as I walk away from it after a run in it, I would appreciate any ideas as to what it might be, other than that and a rattle from the front offside on anything other than a snooker table surface its runs great, its gone through 3 mot's and nothing has shown up, many thanks
User avatar
myglaren
Forum Admin Team
Posts: 25366
Joined: 02 Mar 2008, 13:30
Location: Washington
My Cars: Mazda 6
Ooops.
Previously:
2009 Honda Civic :(
C5, C5, Xantia, BX, GS, Visa.
R4, R11TXE, R14, R30TX
x 4888

Re: moaning noise after run

Post by myglaren »

Try leaving the handbrake off and leave it in gear.
If that doesn't eliminate it I expect it will be one of the suspension struts a bit worn and vibrating as the car settles.
User avatar
CitroJim
A very naughty boy
Posts: 49531
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Re: moaning noise after run

Post by CitroJim »

Some Xantias make that noise pretty regularly after a run and it's nothing to worry about at all. As you say Steve, just the front settling...

High pressure hydraulics can make some funny old noises..

The rattle is more than likely the drop link and they can look and feel OK but still make a racket. Cheap ones from ebay tend to be quiet for several hundred microseconds after fitting before rattling again...

It could also be the lower swivel joint but if that's the cause of the rattle the MOT man will normally have sucked a few teeth and declared his unhappiness with it.
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
mendedit
Posts: 90
Joined: 27 Feb 2009, 20:12
Location: The Bores Inn
My Cars:

Re: moaning noise after run

Post by mendedit »

I used to hear the exact same thing after a shopping trip with my wife but
found I don't notice it two years on
The world is full of them and a lot are in
bill hughes
Posts: 229
Joined: 30 Jan 2013, 13:22
Location: West Sussex
My Cars: 1994 xantia 1.9 tdi sold on and still going strong 2ooo xantia 2.0hdi estate 1998 Renault megane 1.4
x 2

Re: moaning noise after run

Post by bill hughes »

thanks mendedit but my wife wont let me go shopping with her anymore, she says she hates to see a" groan " man cry when she's spending my money
User avatar
MTND
Posts: 122
Joined: 10 Aug 2010, 22:04
Location: Needingworth
My Cars: Xantia 1.9td sx early N reg 1995. owned 17 years!
Alfa Romeo 916 Spider 2005.
Ford Focus Titanium X 2017, Nearly done 300 miles

Re: moaning noise after run

Post by MTND »

CitroJim wrote:Some Xantias make that noise pretty regularly after a run
I think the funniest thing I remember was someone else's car in Lavenham which groaned when they left it and the couple walking past at the time jumped out of their skins! :-D
Gave an opportunity to talk about Citroen's to them 8-) :lol: :lol:

Mark
1995 Xantia 1.9 TD SX owned 17 years
Alfa Romeo 916 GTV Spider 2005
Ford Focus Titanium X 2017
User avatar
CitroJim
A very naughty boy
Posts: 49531
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Re: moaning noise after run

Post by CitroJim »

That made me :lol: a lot Mark :-D

Xac's does it quite regularly and it almost sounds rude...

A Xantia blowing a raspberry...
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
red_dwarfers
(Donor 2020)
Posts: 2504
Joined: 29 May 2008, 15:59
Location: Zomerzet UK
My Cars:
x 54

Re: moaning noise after run

Post by red_dwarfers »

Very funny :lol:

Mine groan sometimes, I put it down to a lack of lubrication on the front struts.
Kev

'19 C4 Cactus 130 Flair
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: moaning noise after run

Post by Mandrake »

A loud groan from the front suspension shortly after exiting the car is a common quirk with Xantia's. My previous Hydractive 2 Xantia would quite often do this with the groan lasting as much as 5 seconds, and my Dad's non Hydractive Xantia also did it occasionally although far less often.

It's caused by the front anti-sink valve closing just as the height corrector is open making a downwards correction to the height.

The anti-sink valves are not designed to close during an active flow (such as the height corrector lowering the car) and it sets up a parasitic oscillation in the anti-sink valve that causes one of the pipes that runs across the firewall from the anti-sink valve to oscillate and vibrate against its mounting, a bit like a poorly supported water pipe hammering - the pipe is where the noise actually comes from.

Apparently there was a Citroen modification note that changed the mounting for the pipe to prevent its vibration from making an audible noise. (Probably just an extra rubber grommet clamp at the right place along the pipe to better support it and damp the oscillation)

Because the noise only happens if the anti-sink valve is closing at the instant the height corrector is lowering the car it usually won't happen if the accumulator sphere is in good condition - as long as the pressure at the pressure regulator is maintained well above the suspension pressure until after you have got out of the car and the car has corrected its height down then the noise won't happen.

So if your accumulator sphere is good and there is no unusual pressure loss in the hydraulic system it generally won't happen unless you sit in the car a long time before getting out.

In the case of my Hydractive 2 Xantia I had a leaky front electrovalve which drained the accumulator pressure quickly after the engine was turned off which is why it often groaned. After I replaced that electrovalve the groan went from frequent to very rare.
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
User avatar
CitroJim
A very naughty boy
Posts: 49531
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Re: moaning noise after run

Post by CitroJim »

If the Hydractive electrovalve is really leaky then it'll be much less a groaning noise and more like the noise of a flushing toilet....
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: moaning noise after run

Post by Mandrake »

It's not the electrovalve that makes the noise Jim, (well, a leaking electrovalve does make a very faint hissing noise of its own that's easily missed) it just helps bring about the conditions that are needed for the groan to occur - which is a rapid loss of system pressure after the engine is turned off.

As I said, unless you sit in the car 10-15 minutes or more before getting out, the noise should not occur as there will still be plenty of system pressure to keep the anti-sink valve firmly open. If the pressure drop causes the system pressure to be marginal (near equal to suspension pressure) by the time you get out of the car and it is adjusting itself down, the groan can occur. The noise comes from a pipe running along the firewall.

If the car is non hydractive its almost certainly a flat accumulator sphere as there isn't much else that would cause a rapid loss of system pressure. If its Hydractive 2 it can still happen even with a good accumulator sphere if there is a leaky electrovalve.

Of course any fault that causes the system pressure to leak away quickly after the engine is turned off can potentially cause this groaning noise to occur.

A pressure gauge tee-d into the pressure regulator output on the OP's car I'm sure would show the system pressure dropping quickly after the engine is turned off. Thats how I diagnosed mine. I had a perfectly good accumulator sphere but the pressure was dropping in half in only about a minute due to the leaking electrovalve. When I replaced the electrovalve the rapid pressure drop disappeared, and so did the groan.

By the way my V6 has not made this groaning noise even once, but it has a good accumulator sphere and has very low leakage in the hydraulic system. I've timed well in excess of 5 minutes with the engine off before the hydractive soft mode reverts to hard mode (tested by bouncing the front suspension with engine off and a door open waiting for it to firm up) which is excellent.
Last edited by Mandrake on 04 Feb 2013, 07:32, edited 1 time in total.
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
citronut
Posts: 10937
Joined: 29 Apr 2005, 00:46
Location: United Kingdom east sussex
My Cars:
x 92

Re: moaning noise after run

Post by citronut »

bill hughes wrote:thanks mendedit but my wife wont let me go shopping with her anymore, she says she hates to see a" groan " man cry when she's spending my money
so it only used to do it when with the other half :shock: :-D :wink: ,
maybe the mod's can put this in the useful fix/sticky section :roll: :wink:
Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years
Rhothgar
Donor 2023
Posts: 1758
Joined: 22 Nov 2004, 00:21
Location: Nottingham - UK
My Cars: 2013 Peugeot 3008 Allure 1.6HDi - FD63 FWA VF3**************[VIN obfuscated, can be read by forum staff]
1995 Citroen Xantia 1.9TD S1 - M728 GDL VF7**************[VIN obfuscated, can be read by forum staff]
1996 Citroen Xantia 1.9TD SX S1 - N707 MGP (Currrently laid up)
2000 Citroen Xantia 2.0 HDi S2 - X435 JGJ VF7**************[VIN obfuscated, can be read by forum staff] (Clutch died Dec 2017 - Resurrected Easter Sunday 2021)
1997 Citroen ZX SX TD - P788 AJL
1959 Landrover Defender S2 - Two owners from new
1968 Triumph Vitesse Convertible 2.0
1980 Ford Escort RS2000 Customer - 2nd Owner
1988 Saab 900 T16S - A 1980's exercise in understated Hooliganism...
Oh! and two Harley Davidsons - A 1990 Sportster and a 2003 Fatboy 100th Anniversary (the only vehicle I have owned from new)
x 78

Re: moaning noise after run

Post by Rhothgar »

Mine yawns like Bagpuss!
Post Reply