Single knock when pulling away - Engine mount?

[Ray_]

Hi all,

I've been busy working on getting my 1.5 dCi Clio mk3 in a good state. A part of this was replacing the control arms and tie rod ends. After replacing the driver's side, there is a single knock when pulling away. The only way to avoid this knock is to pull away very gently. It doesn't happen any other time. It's fine turning, accelerating, braking, going over bumps, etc. I also torqued the control arm under load, so hopefully, it isn't that but it seems this type of arm might not need pre-loading anyways. I've looked around a lot, and things like sway bar link rods (anti-roll bar link rods?) and CV joint noise and symptoms are very different to what I'm getting, but it could be those things. I did get this knock very occasionally before doing work down there, so that leads me away from suspecting the replacement parts causing it.

When replacing the control arm, I noticed the rubber on the side engine mount was completely knackered. I have the part number, but I can't find any information or tutorials on replacing it. I'm a bit worried that since it's an engine mount, it might be a right pig to do. It's the one labelled 6 - part number 8200127321. It might be less of an engine mount and more of a subframe mount. It seems easy to remove from the subframe, but I can't see how to remove the top bolt, and whether I would need to support anything.

Do you guys have any ideas about the knocking, and where I might be able to find information on replacing this part?

 

[Amp540a]

My 172 does the same on near side , just that initial crack sound on pulling away . There is no obvious play in suspension and it is on my to do list once I have finished putting the interior back in following a water leak.
I believe it is a common issue and read that some owners had changed several components without success.
Someone else will have more info for both of us on the cause and how to remove your mount.
So I am no help really but we are not alone.
D

 

[Ray_]

Mine just passed it's MOT with nothing wrong and the tracking was done with no real issues. Annoyingly though, on the other side, the tie rod end has slight play - caught by the tracking machine. I just replaced it this summer. Serves me right for buying a cheap one I guess!

If I ever fix it, I'll post here how I did it. I think I'll wait for some slightly better weather though 😂. Glad I'm not alone, but sorry to hear about your clunking

 

[Martin_172]

is the bolt on the lower arm (the front one, not the rear that goes upwards) in the correct way, I recall coming across this before and someone had put the bolt in back to front and I'm sure it butts up against something so isn't fully tight when it feels tight!

 

[Ray_]

is the bolt on the lower arm (the front one, not the rear that goes upwards) in the correct way, I recall coming across this before and someone had put the bolt in back to front and I'm sure it butts up against something so isn't fully tight when it feels tight!

Definitely in the right way round. I couldn't forget which way round it went in because it took me so long to get it out 😂 It's such a pain. You have to take the radiator support bracket off to get to it. It's a very long bolt, so I'm not sure if it could go in backwards, but I torqued it to spec and the nut and bolt are touching the metal flat. Good shout though, easily done.

 

[rosco454]

I had the same recently, tracked it down to the ball joint to wishbone bolts being a fraction loose.

 

[Ray_]

I had the same recently, tracked it down to the ball joint to wishbone bolts being a fraction loose.

Interesting. That ones pretty easy to access so I'll give it another torque up this weekend. I really wish the horizontal bolt wasn't behind the radiator support bracket, else I'd go torque that again too. If I go to do that, I'll just replace the engine mount that that bolt holds on to cover my bases and report back.

 

[Ray_]

I had the same recently, tracked it down to the ball joint to wishbone bolts being a fraction loose.

I checked it today and it was still torqued to 70nm. I made it 75nm for good measure and unfortunately no difference. I installed this control arm less than a month ago, and I'm pretty disappointed about the condition of it. Apparently Quinton Hazell is a good brand, so not sure what went wrong there. Also double-checked the cone size of the old and new one and they're both 18mm. Since the knocking occasionally happened before, I don't automatically think its the part, but it doesn't inspire confidence.

 

[Martin_172]

remove the top engine stabiliser and see if it disappears (you will have a bit more engine movement, but its still fully secure) I've had so many knocks and bangs come from this even when it looks new and doesn't appear to have any excess play.

 

[Ray_]

remove the top engine stabiliser and see if it disappears (you will have a bit more engine movement, but its still fully secure) I've had so many knocks and bangs come from this even when it looks new and doesn't appear to have any excess play.

I'll have to give that a go when I figure out the equivalent on my car. Your layout is quite different, and definitely much nicer & cleaner ;D

 

[Martin_172]

I'll have to give that a go when I figure out the equivalent on my car. Your layout is quite different, and definitely much nicer & cleaner ;D

That's a press photo from a 197/200 your car will have the same mount though