Xantia V6 4HP20 driving modes not working?

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

Moderator: RichardW

User avatar
xantia_v6
Forum Admin Team
Posts: 9052
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 825

Re: Xantia V6 4HP20 driving modes not working?

Post by xantia_v6 »

I don't think any of my V6s, Xantia or XM have had the wobbly warm start issue. The XM idle speed does occasionally creep up a couple of hundred RPM, but I think that is the result of having to ride the clutch a little while parallel parking on a slope (oh for a handbrake).

The screen fogging on a warm start can be just condensate from the A/C, switch off the A/C for a day and see if it goes away.
Stempy
Posts: 1626
Joined: 26 Feb 2004, 23:21
Location: Cloud Cuckooland
My Cars: C5 V6 Mk1 assainated by wife
Renault Kangoo 1.6 auto, tarted up and remapped
Still missing the Xantia V6
Not missing the AX
Contact:

Re: Xantia V6 4HP20 driving modes not working?

Post by Stempy »

C5's do it too...

Starts ok, but wobbly idle until it settles in.
CitroJim wrote:
Mandrake wrote:I'd say difficult hot starts followed by a wobbly idle for 5-10 seconds are quite common on this engine although not necessarily "normal". (Did they do it when new I wonder ?)
I don't know Simon but all the V6s I've owned have done it to a lesser or greater extent. That's four and counting :-D
It infuriates me to be wrong when I know I'm right

Lexia ponce

http://perception.dyndns.biz/~avengineering/index.htm
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: Xantia V6 4HP20 driving modes not working?

Post by Mandrake »

xantia_v6 wrote:I don't think any of my V6s, Xantia or XM have had the wobbly warm start issue. The XM idle speed does occasionally creep up a couple of hundred RPM, but I think that is the result of having to ride the clutch a little while parallel parking on a slope (oh for a handbrake).
If it happens while you're parallel parking that's probably normal - the power steering pressure switch raises the engine idle speed by about 200 rpm when you turn the steering under load...

As for the wobbly idle - I think most injection petrol engines suffer to a greater or lesser degree from vapour lock in the rail when left to sit with a hot engine for a while - it's very difficult to eliminate completely, only minimise. In fact many cars have had service bulletins and modifications after the factory to try to combat excessive vapour lock, such as fitting heat shields around certain injectors...

Preventing rail pressure leakage while the car stands minimises the effects but I believe that at least on this engine design that any difficulty starting due to vapour lock then triggers an idle speed oscillation that is actually due to a poorly functioning ICV.

You can see in my video that after the initial start and idle surge that it drops back to a speed that is slightly too low but then quickly and precisely adjusts the speed without overshoot and then holds steady.

On old V6 the idle speed would drop below normal, surge well above normal, drop well below normal, surge above normal etc... My hunch is that is due to a "lumpy" ICV that doesn't turn smoothly in response to the signal from the ECU. (Worn or dry pivot bearings) By the time the ICV does come free and start to turn it then moves too far so the ECU keeps over correcting in both directions.

When I cleaned out the seized ICV in new V6 with carb cleaner I then sprayed lots of spray grease into both ends inside the ICV in the hope of getting some grease into the bearings. Something I didn't do when I cleaned the ICV in old V6 where I just flushed it out with carb clean and left it dry.

I don't know whether the grease went into the bearings and if so whether it helped, (maybe the bearings are just less worn due to the much lower mileage) but I do know that the idle speed control is very precise and smooth on new V6...
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
DSFan
Posts: 6
Joined: 03 Sep 2014, 18:15
Location: Finland
My Cars:

Re: Xantia V6 4HP20 driving modes not working?

Post by DSFan »

Hello again.

I havent had the time to dive in to this problem with buttons.
But other day when it was wet, i step in to a car and saw this.
Image
Would propably easily cause the failure by water getting in to connections?
What do you think? The water seems to come thru antenna...
Suppose this panel is easy to remove just with a this screwdriver?
Citroen DS 23 ie BVH 73 (Project that goes on forever)
Xantia V6 Automatic 97 Exclusive
User avatar
CitroJim
A very naughty boy
Posts: 49526
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: Xantia V6 4HP20 driving modes not working?

Post by CitroJim »

Ahh yes, the switch assembly is not just switches but quite a complex little electronic circuit so dampness from a leaky roof could well cause it some upset.. It may have already started to corrode the printed circuit board.

The switch assembly is removed by clipping out the whole panel around the gear selector lever from the centre console moulding. Use a small blade to prise up one edge of the panel and it'll quite readily pop out.. The selector switch assembly can then be popped out of the panel from below.

Maybe drying the switch assembly very well and then cleaning any corrosion using Isopropyl Alcohol (IPA) or other gentle electronics solvent may restore it to working order...

Do repair that leak too!
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
DHallworth
Donor 2023
Posts: 2382
Joined: 20 Nov 2005, 17:05
Location: Glasgow
My Cars:
x 119

Re: Xantia V6 4HP20 driving modes not working?

Post by DHallworth »

We had this fault on our old silver V6 Xantia when we first got it and I found that the plug had just come loose on the bottom of the panel. Plugging it back in cured the fault. I'm sure I managed to get the switch up on it's own without taking the whole surround up but I might be wrong.

If you do decide to replace it, I might still have the one from the V6 that I stripped for parts earlier this year.

David.
'98 Xantia Activa V6 :-D
'00 XM V6 Exclusive
'09 C5 2.7 HDi Exclusive
‘10 C5 3.0 HDi Exclusive
'12 C6 3.0 HDi Exclusive
'15 C4 BlueHDi Feel
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: Xantia V6 4HP20 driving modes not working?

Post by Mandrake »

If the V6 you stripped for parts was a S2 David unfortunately it won't be compatible with a S1. :( The circuitry for the sport/snow control unit is very different between S1 and S2.
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
Post Reply