Yea... a harsh knock, sounds like its in the car where the noise must be traveling up the strut to the top mount. and the odd twang noise from the spring it sounds like.

 

I've had BC's on my 03sti since Feb 09 and 6k miles.
The only noise I hear is a knock from the NSR when going over deep potholes that I've failed to avoid. other than that they have been great, the old OEM units made more noises to be honest.

dipster

 

"Twang!" or "Clonk!" is the best way of describing mine. Mine were only fitted at the beginning of last year and they were great until about 4 weeks ago when I fitted all the Perrin goodies.

Still haven't sussed it out.

 

My car is also polybushed- cant say I notice a knocking as described above (although I appreciate the responses helping me understand) but certainly you get greater transmission of noise, as you would expect.

 

Has anyone with the 'clunk' checked the rear cross member bushes? See the picture on post #29 of this thread:

https://www.scoobynet.com/scoobynet-...ing-noise.html

The bushes on mine have significant play in them and obvious marks where the metal surrounding the bush has impacted on the underside of the car body.

Definately the next thing I'm going to try.

Mark

 

I'm getting exactly the same after fitting my BCs

 

Gents,

I've had the VERY same problem with knocking BC Coilovers on my 2.5L '06 WRX since I had them fitted back in September. Incessant knocking from the rears on both sides - very very annoying especially when travelling at slow speeds (0 - 40mph) on slightly bumpy roads and in London that's EVERYWHERE! Also used to get twanging off all struts especially just after adjusting the dampening rates.

Was in touch with BC and suggested a few things with spring pre-tensioning and checking that bolts were tight, etc. with no joy!

Finally I got so frustrated I took it up to TSL Motorsport in Keyworth and Collin and Pete took a look at it and found a few problems with the set up:

1) Ride heights on both rear dampers were not the same; 10mm off from each other
2) Spring dampening rate was not right and had to be adjusted
3) Bolts on the underside of the struts were not tight enough
4) Alignment was completely out of whack!

After they stripped the suspension down and fitted new rubber top mounts (BC Suggested that the system would require rubber top mounts as they come with pillow ***** - the rear struts already had rubber top mounts fitted so don't know why they suggested it), they ensured the ride height and spring rates were correct, and re assembled and aligned the whole set up to fast road settings, it now is a LOT LOT quieter than it was. The incessant knocking has practically disappeared although there is still 'clunking' over bumps which is kind of to be expected given the nature of the type of strut, but very bearable in comaprison to before. Even my Dad noticed how much quieter it was and he's closing on 80!!! (Thanks Dad!). Oh and twanging has gone too!

To cut a long story short, if you're having problems, get them fitted professionally by someone reputable who has the right equipment - don't cut corners - it could have been any combination of the stuff done above that could have sorted out the problem - I read on one of the posts that changing the rubber top mounts could have made the difference as when they took off the old ones, there was a bit of play in them before the rubber expanded back into shape! I would recommend TSL of course as they sorted it out for me - but some food for thought for you guys/gals.

If you need any more info, let me know! Good luck - I'm glad it's over...for now!c

 

We find that kokekans experience is quite often the case in terms of noises and issues with coilovers. In the majority of cases its install issues that are leading to problems, its only a small percentage of coilover kits that actually have a fault wsomewhere.

As Ive said before, feel free to give us a ring to run through what to check if you are experiences an issues with a BC Racing kit. Ask for Kev 01274 683633

Also note that we do now have new rear springs that fit with the original later new age rear top mount and provide the ultimate in terms of ride quality and noise so if you want to absolutely maximise ride quality then this is the rear set up to specify when ordering. These springs are only available in 4kg.mm and 5kg.mm rates.

 

Bren,

Do these new springs fit the OEM top mounts for both WRX and STI?

Thanks, Mark

 

Yep but only new Age, this wont help the Classics.

 

Hands up if you are a muppet? (I have my hand up!)

While there is still a little thudding as expected due to stiffer suspension, my mysterious rattle was the screwdriver that had fallen out of my toolkit, and was hiding in the space under the jack. Ill get my coat............

 

I would have said most knocks could be attributed to top mounts. As far as I know though the movement of the rear suspension on an Impreza causes greater than normal side loads through the struts and does tend to make dampers fail early especially if they are not inverted type. I'm told AST have solved this problem on their units?

 

Inverted are worse for causing shocks to fail.

 

Finally got my BC's sorted. No knockig at all. Steve sorted the problem at Dyno Demon. They are ace. They feel like they have been put on from the factory. Really impressed with them now i have had all the 'noise' issues sorted. Hope you all get yours sorted.

 

Waht did they fix??

 

I've done similar

 

ADE_STI,

Could you please provide some more details on what was changed to resolve your noisey BC's.
I have been having 'noise' issues with mine from the day they were fitted, but I have not had the time to investigate it fully yet.... any advice would be most appreciated

 

Gents,

One week on after the refitment of the coilovers, everything is pretty much the same. Still tight, however, definite 'rattle' still evident in the shocks. Nowhere nearly as bad as before, but enough to often wonder if that rattle is supposed to be there.

Bren, is that normal? Seems to ONLY rattle on slightly bumpy roads again at low speed - not so much so on big bumps. Literally sounds like the springs rattling. Handling is still tight.

 

i just want to say something about all this aftermarket suspension its a load of junk it meant for the track and the track only really and it needs rebuilding alot. are British roads knock the sh@t out of it me and my mates have had every type of worth having and and it just don't last my mate has gone through loads of this stuff on his evo and i have doen a lot on my scooby, it got to the point where this ectek stuff, the company gave him group n suspension for three as he had broken so much of it he is running 430bhp 460ft in a 2.3 im running 390bhp -370ft and ive got some sti 6 suspension and some good springs and it makes for a very good road car and guess what i have had it on for over a year no no knocks no bangs no head ache i would to get the bilstien sturts on i think as they work wonders on the evo x fq 400

 

I have exactly the same noise but am not too bothered & accept thats inherent in this type of suspension type. Though I will soon increase the pre load on the rear to see if this helps. As strangley enough when I turn up the rebound/stiffness at rear from e.g. to 14 (from soft zero) to e.g 18, the noise greatly reduces. This makes me think that the preload may have to be increased (through adjustment of the collars) as affect would be similar. .

 

Some of the pillowball rear top mounts can rattle ever so slightly as theyre metal on metal.

Have you checked preload to see if it is in fact the springs that are rattling?

We have found that the silliest of things can cause noises, including the rear damper adjusting **** if its not attached tight to the strut.

One thing that was mentioned as a possibility is the adjuster **** itself. They are sprung and we did wonder if it is bouncing up and down and causing a very light rattle. We dont have any cars here with any noisy coilovers so havent been able to check the theory in house but it might be worth removing the adjusters completely, see if that helps. If it does then we can send the feedback back to the factory and ask them to alter the **** design

 

Thought Id hijack this thread as sspension seems a hot topic at the minute. MY04 STi UK has hit 30,000 miles an im experiencing some strange suspension movement particularly from the rear N/S. When coming to a stop or setting off steady it feels/seems the suspension has a very very initial "jerky" movement. Im not sure what this actually is but there is also some slight knocking at low speeds over rough roads.

Any help please? Also if the shocks are shot what really is the best resolution, subaru replacement or aftermarkets?????

Regards

Steve

 

You need to take them apart on the bench and re-grease them , the top bush dries out and then wears. Grease them before it's gets really bad and you will save them.

dipster

 

Its very hard to diagnose problems like this Steve over the net probably best to get it looked at by a Subaru specialist. Heres my 2 pence worth anyway, the knocking sounds like the famous rear shock knock the jerky movement could be down to worn bushes or drop links

 

Ok, I will try and keep all opinion out of this post and only write what is factual.

My car is a 03 sti type uk
I ordered a set of BC coilovers from the last group buy. I did not put any thought into top mounts so I assume I received the standard BC top mounts.
Not having the equipment and the experience to fit the coilovers myself I took it to a Slowboy to do for me. The work I requested was fitting setup and alignment.
When I got the car back, I was happy with the ride quality, happy with the ride height, happy with the handling but very unhappy with the noise levels.
The front two made no noise.
The back two made lots of noises, I find it difficult to describe noises, but there were about 4 different ones. Noises when going over low speed bumps, noises when going over medium sized bumps, and big noise when going over a pothole. On top of that there was a constant rattle type noise coming from the near side rear, this noise was audible almost immediately as soon as the car starts moving, regardless of speed, this noise sounded like it was coming from the top mount.
I contacted APEX performance and eventually spoke to Kevin. Kevin made some recommendations of things to check, from memory these were,
- Disconnect the drop links to make sure they are not making noise
- Check bolts to ensure that they are all tight
- Check the adjusters (this was from a later conversation)
- Check to make sure the top mounts I have are the correct ones.
I checked the top mounts and they were the right ones.
I checked the adjusters and they were not making a noise.
I checked the bolts and they were fine
As for checking the drop links, I did not do this.
On top of this I stripped out the back of my car (removed seats, everything from boot, wooden spare tyre cover etc etc). None of this made any difference.
I then checked the rear parcel shelve thing, this was also not contributing to the noise.
I then got numerous people to sit in my rear seatless car and try and work out where the constant rattle was coming from. Most people were confused and could only suggest that it may be coming from the rear nearside BC.
I spoke to Kevin again and he recommended that I fit the OEM rear top mounts, and as a result he supplied me with the springs so that I can do this.
After a while (due to snow and broken radiator), Slowboy kindly offered to try the OEM top mounts for me. According to him the noise levels improved massively from just changing the top mounts from the BC top mounts to the OEM top mounts. The alignment was then re-checked and found to be fine. His service

I have now got my car and have been driving it two days and there are no noises from the suspension at all. It rides good handles good and makes no noises. I enjoy my car again
From my experience and my experience only. The possible problems with my suspension were

- Faulty BC rear top mounts
- BC rear top mounts not correctly designed for the newage application

I am happy that my car is now sorted. But I was very unhappy with the whole experience. It would appear that poor noise refinement on the newage application is a known problem for BC. I would have saved a lot of time and sadness (i love my car ) if this was highlighted at the start so that I could have had the option of using the OEM top mounts the first time around.

Thank you Slowboy for your patience and kindness.
Thank you Kevin for eventually letting me know about the alternative spring / OEM top mount set up, and sending it my way.

 

I found another clunk to be my harness's on the eye bolts.

 

so what is the conclusion.....dont buy BC coilovers????
Please advise, as I was about to buy a set for my newge sti...........

 

really good coilovers for the money. just have to put up with the noise or change the rear top mounts

 

really good coilovers for the money. just put up with the noise from the rears or change the top mounts

 

Id love to try the rubber top mounts that we were supposed to get with them but they never arrived,Im about to remove my whole BC kit to send back, its 10 month old and rattled from the start.