[C5 X7] Strange intermittent 'knock' from front when going lock-to-lock.

[the-termin8r]

Hi everyone,

I've encountred a strange and intermittent issue in the past week or so that I can't seem to pinpoint or deliberately reproduce to get footage of. I've noticed it maybe 2 or 3 times so far. When the car is static and I turn the wheel lock-to-lock I hear a single 'knock' as I'm turning the wheel to full-lock-left. In terms of sound, the best comparison I can give is like the knock of a ruined wishbone bushing over a sharp bump, but not as loud or jarring.

Because it's been so tricky to reproduce, I'm not sure what the conditions have to be. I think it might have something to do with the car facing down a slight incline like a driveway (more weight over the front wheels). It seems to only happen when turning left, I don't know how far along the travel of the wheels it happens (i.e. whether it's before or after the centre point). I tried troublshooting by just going lock-to-lock a few times in the car park at work (level ground), but couldn't get it to knock. I raised the suspension to see if maybe I can see something around the struts or the wishbones (without getting under the car), but couldn't see anything obvious. The car otherwise feels completely fine to drive and had one of its wishbones (left, if I recall) replaced in Dec.

I don't know if this is suspension-based or if it's a symptom of a failing rack, but I feel like I'm in the very early stages of an expensive problem. The only thing I will add is that in the last couple of weeks I've hit a couple of rather nasty, and unavoidable, road craters. Perhaps they could have actually done damage this time? As far as I know, the car has never experienced such an issue in the 9 years it's been in my family under my dad's ownership (I spent those years as a passenger).

Thanks for any help.

[Stickyfinger]

Lower (Fripp) Joint

No'14

[MattBLancs]

I have very similar knock / clunk. Very few on road conditions seem to trigger it, most common seems to be change from forward to reverse or reverse to forward, but not repeatably so and seems also to be linked to a bit if steering lock applied or taken off in conjunction with the change in direction. So maneuvering on and off the driveway - which also has a bit of suspension movement thrown into the mix!

Had front of car up in the air at the weekend but couldn't spot anything obviously with play.

I've read on here of the FRIP being often a loose collection of rusty roller bearing elements on removal and is crying out for a grease nipple to allow it to be packed full of grease.

Has anyone added a grease nipple to this joint? Bottom centre of the FRIP? It's tight for space but wondering if can just get a 90° grease fitting in at this position.

[the-termin8r]

Quick update: Went to run some errands this morning, pulled into a parking space (forward and turning right) and it knocked again. Went out with my dad driving just now to try and reproduce it, got maybe 3 or 4 clunks in about 10-15 mins all while deliberately driving at about walking pace or slower and doing multiple rotations of the wheel. Now it's happening when turning both left and right, but is still very intermittent given how much turning we had to do.

[GiveMeABreak]

Is this only happening on turning the steering wheel?
Does the car clunk when 'taking off' or braking suddenly even at low speed (regardless of steering wheel angle)? I'm trying to eliminate one clunking symptom that I had.

[the-termin8r]

Yes, it's only when turning the wheel and at very very low speeds (?5 MPH). If I turn the wheel a bit and leave it there while moving (i.e. driving in a slow circle), it's fine. It only happens when the wheel is moved. When driving normally, it's as if nothing is wrong. No issues with hard acceleration or braking.

[GiveMeABreak]

Ok so that rules out the wishbone bush where I've highlighted in Red, which is the problem I had.

So if it's steering related then possibilities for Banging, Knocking or Creaking are:

• Steering Rack
• Steering Ball Joints
• Steering Gaiters
• Steering Track Rods
• Electro Pump
• Steering Column

I'd initially rule out the electro pump and Steering Column at this point and focus on the first four items.

[the-termin8r]

Yeah, this car's been through 3 or 4 wishbones at this point, I'm well familiar with how it feel when it fails / starts to fail. Thanks as always for your help. Is there any more light troublshooting I could do to narrow the list down before taking it to a garage? I don't really have the tools to teardown any of the suspension beyond removing the wheel.

[GiveMeABreak]

Unfortunately there's not a lot else I can suggest as it needs putting on a ramp and having the various components tested to localise the issue.

[MattBLancs]

My symptoms are very similar to the-termin8r's.

I'm going to order a pair of 90° grease nipples and new FRIP. Various cheap ones starting around £10 per bearing - are they terrible or worth trying if my greasing plan cures / greatly delays the main failure mode?

Some good info on replacement of the FRIP here:
https://www.frenchcarforum.co.uk/forum/ ... 94#p439194

Also here, from about the post this links to onwards:
viewtopic.php?p=559774#p559774

Also a good bit if info on grease nipple fitment here on the video linked in of the above threads:

Nipply

From here:

[kantica]

I had intermittent knocks also, but at first while reversing and breaking. It progressed to knocking while driving forward and breaking.
All this while having steering at some angle near lock. I changed brake caliper guide sleeves and knocking went away.
Sleeves: https://digital-assets.tecalliance.serv ... df331f.jpg

[MattBLancs]

I had intermittent knocks also, but at first while reversing and breaking. It progressed to knocking while driving forward and breaking.
All this while having steering at some angle near lock. I changed brake caliper guide sleeves and knocking went away.
Sleeves: https://digital-assets.tecalliance.serv ... df331f.jpg

Good to know, thank you. I didn't investigate the brakes when looking for my noise, will do so soon and see if I have a similar fault

[MattBLancs]

I know above Marc has ruled them out based on what symptoms fed back, but I have also had a read here:
viewtopic.php?p=644727#p644727

Had a quick look online based on part number 3656.04 (which I believe is actually the whole carrier ?? as Citroen don't list the bush on its own) and am tempted to try a cheap pair of them (£12 for two, delivered! https://www.ebay.co.uk/itm/143959886710 )

Seems sensible whilst I am "in the area" changing the FRIP bearing(s = both sides together, if sufficient enthusiasm prevails!)

[the-termin8r]

Aren't the bushings themselves an absolute bitch to remove on their own? I always thought that that's why Citroen always do the whole wishbone. Eitherway, I unfortunately don't have the time or tools to do it myself, so will have to set up an appointment to have it looked at.

[MattBLancs]

Aren't the bushings themselves an absolute bitch to remove on their own? I always thought that that's why Citroen always do the whole wishbone.

I'll tell you soon I guess!!

It gets to be a funny world with dealerships work as the extortionate labour chargest has a significant impact on what's viable to change - i.e. my £6 bushing would soon be dwarfed by the hours of labour to change it, and so a quicker nut and bolt change of the whole component in which the bush fits is the way forward.