Knocking whilst at a complete stop??

[Tommo.]

Bit of a weird one- I've been experiencing a knocking noise, it happens when braking just before coming to a stop, but then also when the car is completely stationary (even if the engine is off!!).

For example, i can be sat at the traffic lights and it will start knocking, it is a continuous knock and lasts for 5-10 seconds. It even does it when i've parked up and turned the engine off.

It doesn't happen all the time, more so when i've been using the car for a little while.

It appears to be coming from the front of the car on the drivers side.

Does anybody have any idea what it could be?? I have searched online and nobody seems to have experienced a similar problem..... :banghead:

Any help/pointers would be greatly appreciated.

 

[not normal dan]

That's a weird one mate, especially how it does it at stand still when turned off.

Your always welcome to pop over next week and I'll have a quick listen

I fly out to Italy on Friday

 

[clioben182]

Cooling fan?

 

[Tommo.]

That's a weird one mate, especially how it does it at stand still when turned off.

Your always welcome to pop over next week and I'll have a quick listen

I fly out to Italy on Friday

Nice one mate, may well take you up on that!!

Cooling fan?

Not something i'd thought of, cheers Ben! How do you check it? Although it does sound more like it's coming from around the drivers footwell....

 

[not normal dan]

Cooling fan?

Be very surprised if it's that, cooling fans hardly ever come on on these clios

 

[Tommo.]

It feels like it could be brake related if anything. The discs and pads are reasonably new. Fluid was replaced about two weeks ago and it started shortly after that....

 

[not normal dan]

Well the servo and master cylinder are on the other side of the bulkhead on that side

 

[Dan@SJM]

Is it only when your foot is on the pedal?

 

[Chip-mk1]

If its doing it while totally stationary and with the engine not running it has to be something electrical surely?
As nothing else will be moving I mean.

 

[Tommo.]

Is it only when your foot is on the pedal?

I can hear a bit of a knock/clunking literally just before coming to a stop at low speeds. I wasn't sure if this was because i have OEM pads but no anti-rattle shims, so i've got some of them to pop in and see how it is.

However, the knocking when the car has actually stopped happens when my foot is not on any of the pedals.

 

[Tommo.]

If its doing it while totally stationary and with the engine not running it has to be something electrical surely?
As nothing else will be moving I mean.

The "STOP" and "BATTERY" lights flickered on and off a couple of times one morning, but it has only done it that once so I haven't thought anymore of it tbh. Not sure if it could be related?

 

[AlexW]

Carbon Canister clicking is my thoughts.

 

[Chip-mk1]

Carbon Canister clicking is my thoughts.

Yeah its in the right place and it fits the "MO" of being able to make noise without the engine running, although its not normally so noisey.

Unplugging it would be a good place to start.

 

[Tommo.]

CC is more of a ticking/tapping noise isn't it? This is a bit like a continuous clunk and it's intermittent, in that it can go 50/60 miles without doing it once!

 

[Chip-mk1]

CC is more of a ticking/tapping noise isn't it? This is a bit like a continuous clunk and it's intermittent, in that it can go 50/60 miles without doing it once!

I just dont see how you can have a clunk from a stationary car with the engine not running TBH!

Hope you can get to the bottom of it mate

 

[welshname]

Do you have two threads for this?

My replies from weeks ago suggesting carbon canister and just the noise if you're exhaust cooling have gone.

 

[Tommo.]

Thought i'd add to this - i'm terrible at explaining things lol!

It only makes the knocking noise immediately after i've stopped the car, there's a quick succession of knocks that last around 5-10 seconds and it feels like it's coming from the drivers side front wheel / brakes.

It doesn't happen again when the car is stationary / engine off - just after i initially come to a stop.

And as i said, it is intermittent, it usually happens after i've been driving a while and i seem to notice it more when in stop-start traffic.

Do you have two threads for this?

My replies from weeks ago suggesting carbon canister and just the noise if you're exhaust cooling have gone.

Yeah sorry mate, it's another thread

I was driving myself mad last night looking for some other things to check and found nothing so i thought i'd pop another thread up wording it differently. I'm heading to Cardiff next week (300 mile round trip) so want to make sure everything is ok before i go...

Appreciate your help as ever

 

[warwickstingray]

Where is the ABS unit on these. This is a normal 172. Is that doing anything weird. Our CRX used to do weird ABS things, pumping and knocking etc but that was a much older system.

I guess the 172 has a similar system to my 206 so this is unlikely and a guess the warning light would come in but I thought it worth mentioning.

 

[barker22]

could it be after a fairly hard stop? something loose in the engine bay being flung forward every so often?

 

[Tommo.]

I was thinking along the lines of a sticking caliper...

 

[Vaughan]

Sounds like engine run-on after the ignition is cut, and the rough running is banging engine mounts.

 

[Tommo.]

Thanks for everybody's help so far, given me a few more things to check and research.

Any thoughts on a sticking caliper being to blame? The knocking happens immediately after i've come to a stop (when foot lifted off the brake pedal) and then a succession of knocks continues for around 5 - 10 seconds.

Is it worth bleeding the brakes and replacing the fluid again? I first noticed the issue not long after this was done so could it be that some air got into the system?

 

[welshname]

Can you not get a video of the knock?

 

[Tommo.]

Can you not get a video of the knock?

I will try my best mate, i appreciate it's a hard thing to even try and diagnose without actually hearing it. The problem is it can go such a long time without happening that it's hard to capture. I'll give it a try tomorrow anyway, thanks for your reply

 

[Chip-mk1]

I cant think of any sort of knock from a caliper that would happen for 10 seconds once the car is stationary.

 

[Tommo.]

Ok so still having an issue with this.... it doesn't seem to have got any worse and still only happens after prolonged use, at low speeds / a complete stop.

I was having a look over the car last night and despite everything appearing ok suspension wise, when pushing down on the car, you can hear the noise and it does appear to be suspension related. I managed to grab a video as well, this is with me pushing down on the car. It did sound like it was coming from the top mount, but i'm not sure if that's the vibration/knock travelling up the strut.



Any ideas?

 

[welshname]

There's no way that noise could continue after the car has come to a stop and you're not in it.

 

[Tommo.]

It doesn't happen when i'm not in the car (as far as i know...!!), but it definitely does when the car is at a complete stop.

The noise will generally only happen when at low speeds/coming to a stop, however it does sometimes continue for up to maybe 5 seconds after I have come to a stop. It will also, very occasionally, make the noise when I turn the engine off (even if it has just been stood idling) and sometimes opening the drivers door will trigger the noise too.

I never seem to have straight forward faults.... :banghead:

 

[welshname]

That's not right. It's probably caused by you rocking the car, in which case I'm saying the dampers are fubar.

 

[Tommo.]

That's not right. It's probably caused by you rocking the car, in which case I'm saying the dampers are fubar.

Yeah it had crossed my mind that it could be the dampers. They were last done 4/5 years ago so they're probably due a refurb anyway. If it does turn out to be them, it's strange that i haven't noticed any difference in handling, it still seems spot on in that respect.

 

[Tommo.]

welshname

Just found this video on YouTube, very similar noise to what i'm getting and it turned out to be dampers.....

 

[welshname]

From your video I'm 100% saying the dampers need refurbing. But your other occasions when the car is doing this is REALLY confusing the hell out of me. You might even find you've got more than 1 problem in the end but you almost certainly need the dampers refurbing.

 

[Tommo.]

Me too mate... and everybody else who has looked at it.

Looking at the video of the other Trophy, the noise is 100% the same. I may try swapping the dampers for some cup ones and see if the noises go away before investigating any further.

 

[welshname]

Me too mate... and everybody else who has looked at it.

Looking at the video of the other Trophy, the noise is 100% the same. I may try swapping the dampers for some cup ones and see if the noises go away before investigating any further.

That's the sure fire way of finding out. Doesn't take long to swap them over either. Make sure you get 182 cup dampers, not 172

 

[Tommo.]

That's the sure fire way of finding out. Doesn't take long to swap them over either. Make sure you get 182 cup dampers, not 172

Well hopefully i can borrow a set of 182 cup dampers...... seanpeat309

Otherwise, i think they're only around £40/pc off Adam aren't they.

Thanks for your help, it is very much appreciated

 

[welshname]

If you're going to borrow some then you're best finding some you can borrow for a few weeks. If the noise goes away once you've got the cup ones on then you know it's the dampers. So might as well leave the cup ones on until you've got the sachs ones refurbed.

 

[seanpeat309]

Aha you can borrow them for as long as you want tom its not like you don't live next door. You'll have to get a pair of spring compressors though. And check to see if ecp have any bearings in case yours are collapsed.

 

[Tommo.]

welshname - tagging you as thought you might be interested in this mate.

So today I decided to take the Sachs dampers off the front and put some 182 Cup dampers on. That way I could send the Sachs off for a refurb over Winter. So got started on the nearside first, swapped the dampers over and then moved onto the drivers side, removed the damper and was greeted by this.......

IMG_1425 by tommo1991, on Flickr

Not the best photo, but basically the spring on the off side (where I was getting the knocking noises from!!) wasn't seated properly.

As we'd already swapped the dampers on the other side, we decided we'd put the Cup one on this side anyway, despite being 99% sure the spring was the issue here. Took the car for a test drive and the noises had gone completely!

Now I'm in two minds. Do I put the Sachs back on or do I send them off for a refurb anyway (they haven't been done for four years)?

 

[welshname]

Depends. You might find that they were also fucked!

If you pull the stanchions out all the way what happens to them, do they go back in, were they hard to pull out etc.

 

[Tommo.]

I don't know if I'm being a big girl, but they seem rock solid? As in, I can't lift them out at all...... lol