Citroen C6 2.2 HDI - Suspension

[joaocfernandes]

Hello everyone,

I need some tips, because I am starting to get a little lost with my C6.

So I bought my C6 3 years ago.

When I bought it ride was bouncy like a boat, heights were incorrect. I replaced the two front corner spheres ride improved dramatically, amazing on the motorway . Local roads are very aggressive but car would absorve as it could. Not the same as DS/CX.

Beginning of this year I started noticing some issues with the struts, so I bought one's from ebay . They aren't KYB/Citroen (5271.L5 and 5271.L6) but very similar.
Heights were again checked with Lexia after it. Ride was great.

After struts were fitted first motorway trip was great, about 500 KM. After this car was left in the garage for about 1 month due to travel reasons. When I came back battery was gone and damaged
Well got a new a battery and fitted it. Start the car and the front right side was stiff. I mean really stiff no damping at all. Not even safe to drive.

Got a pair of spheres to it, improved a little , but the front was still stiff. No significant pitching/rolling.
Using UP/DOWN controls I could go from low, to normal but the mid-high and highest position were never confirmed on the RT after being requested.

Another 500 km on the motorway to a location where I could lift the car and checked it calmly with Lexia.
Did the following:

• Checked oil level, with car depressurized.

• Bleed the system at front to guarantee no air was in it.

• Re-Checked oil level, with car depressurized.

• Made height correction, front was at K=161 , rear K=113

• Tested the front/rear solenoid

After I finish I noticed the following, using UP/DOWN controls I could go from low, to normal, and mid-high, but the highest position was never confirmed after being requested (rear raises a little more, but front doesn't).

Drive it for a short trip, front wasn't stiff anymore. Potholes were tolerable but not as good as before the strut change. Noticed some slight pitching/rolling.
Back home, another 500 km on the motorway. Beginning of the trip was reasonable , but after some 100km the car started to pitch significantly more and also rolling. Today morning picked the car for a short ride, when getting back home the service warning and 90KM/h limit appeared on the RT.
After reading that car could sink I took it out of garage, warning was gone.

Unfortunately, don't have Lexia here with me. Any hints where to start looking?

[joaocfernandes]

Just some additional info, the bleeding I have done at the front was done at the right front strut. Is this sufficient? I am now having second thoughts about the bleeding process I did.



This is front right strut which is again stiff.

I read in the forum very detailed posts on the bleeding using the steering wheel, but I am confused since my car has a separate power steering unit with dedicated lds fluid. Is it the same on the C5 X7 and the others C6s?

[Kees]

This point is ok, i read your post, but it seems to me, that there is a problem with the h.p. pomp.
You should listen to it, when you change the high of the car..about the sphere's, here on the forum are more post about complaining that the front is stiff after changing the corner sphere's.
For me it's a bit strange, that these people don't realize, that the center sphere provides the smooth/soft ride.
Last time i try to explain, that inside the stiffness regulator is a needle with a few springs which switch of the center sphere with an electrical signal.
If you don't replace the center sphere, you disrupt the balance between the pressure from the corner, center spheres and the springs inside the stiffness regulator.
In this case the needle wil not release the center sphere.
Greetings,
Kees.

[joaocfernandes]

Thanks a lot Kees!

Appreciate the comment on the bleeding point I used.

Regarding the pump, I hear it when I unlock the car/sit or when I ask to raise the car. I just found it awkward that for all positions RT displays a message confirming position and max velocity and currently only the MAX position is not confirmed. I will search around the pump also.

I had ordered the 3 sphere set for the front from Citroen (Eurorepar), but unfortunately they only delivered the two corner spheres this past week. I hope this week, the 70 bar one is delivered.

If the warning doesn't reappear and I receive the center sphere I will do another trip , to replace the center sphere.
My idea is that the center sphere is on the right side of car underneath the pump, yet I read conflicting information about this.

[Kees]

I have a c5 x7 v6/3.0, the center sphere is with car in front of right weel behind the mud protector.
The C5 x7 2.0 location of the center sphere is on the left side, this is a little more difficult to replace, but in an other post i described it how to do without remove the subframe.
Greetings,
Kees.
P.s. let us now how the result is when you replace the center sphere.

[joaocfernandes]

Hey everyone,

Getting back with some news. When arrived I connected car to Lexia got the following:

C1141
U1118
U2118

Cleaned up all this and started from scratch.

Center sphere was replaced, very easy to access just on the right side as you mentioned Kees. After this suspension improved but not significantly. All the requested positions started to be confirmed on the Radio.

Suspension height movement was slow and awkward, after doing a bleeding and height adjustment I started to notice the recently replaced strut at the right was "slower" to raise and when going for the minimum position a strange noise was made at the end. Although height adjustments were successful, after a short drive the car height at front would change about 2cm up or down. Spend several hours around height adjustments at front.

I took out the height adjustment sensor and checked it with a oscilloscope with 5+ input, voltage would between +0.35 - +4.63volts . Also checkable with a simple voltimeter.
Going into more detail, around 2.2v to 2.8v values were not smooth, relative to angle movement. I suspect total movement is about 90º degrees.

Due to this I ordered an height front sensor and also I contacted the strut seller and he sent me a new front right struct very quickly.

Started with the front right struct, not being experienced with this, it was very complex for me to do, but I used on video from Kyb on youtube to roughly guide me.
After this car improved dramatically (less roll).

For peace of mind I replace the front height sensor and was much easier to make the height adjustments and I observed that the car kept it constant after short trips. I hope this get my C6 going for some more years, I plan to do much more kilometers on it.

Tomorrow will be the real and long test.

[GiveMeABreak]

Great, well done and thanks for the updates.

[joaocfernandes]

Hello,

So car was great at front for about 3 days, yesterday front left got stiff. I am suspecting air in the circuit now.

My problem with the bleeding operation is the following.

Steering wheel on my C6 2.2 is on a separate LDS circuit AFAIK. They don’t share the same LDS tank.

Procedure I have access to says:

- Use Lexia to depressurize (Follow instructions)
- Apply 0.5 bar to LDS tank.
- Start engine
- Wait for vehicle weight to stabilize
- Place in the high position
- Place in the lower position
- ??Turn the steering from lock to lock ??
- Stop Engine.
- Depressurize and check LDS level.

Is this worth doing? I am a little confused on how does this works with the steering.

[Kees]

First try to change the sphere from left to right and right to left, so you make sure that there is no problem with the sphere's.
About the strut you replace, did you buy this one from ebay?
The reason i ask, there is an other forum lid, that have the same problem with the right strut, he replaced it a few months ago, but also a stiff right corner.
Greetings,
Kees.

[GiveMeABreak]

Hello,

So car was great at front for about 3 days, yesterday front left got stiff. I am suspecting air in the circuit now.

My problem with the bleeding operation is the following.

Steering wheel on my C6 2.2 is on a separate LDS circuit AFAIK. They don’t share the same LDS tank.

Procedure I have access to says:

- Use Lexia to depressurize (Follow instructions)
- Apply 0.5 bar to LDS tank.
- Start engine
- Wait for vehicle weight to stabilize
- Place in the high position
- Place in the lower position
- ??Turn the steering from lock to lock ??
- Stop Engine.
- Depressurize and check LDS level.

Is this worth doing? I am a little confused on how does this works with the steering.

Ignore the first part (depressurising) - you are past that point. Adding the pressure (0.5 bar) is in case it won't start to rise after you've completely depressurised the system. Follow the other parts, but you should turn right to left slowly and a few times, but don't hold the steering wheel when it reaches the left or right lock limit - repeat the turning and then return to centre, then check levels.

Your will still have shared LDS fluid from the same reservoir regardless of the type of power steering system fitted.