[imygaf]

Hi guys

I recently had bc coilovers installed. After which i was getting a knocking noise from front left , not just when hitting potholes but on generally uneven roads.

Contacted BC who advised to do a damper test which showed it to be faulty. A replacement was ordered and fitted today. The garage phoned today to say there has been an improvement but still a knocking noise. They even swapped front left amd right to see if the noise changed to other side but it remained on the left.

They spent a few hours checking bushes and so on but still have not determined where its coming from so im without the car for another day tomorrow as they do further checks. So far they say everything seems tight and no play.

Can anyone advise what may be the likely cause? Its really annoying me now and taking away from enjoyment of driving the car.

[R0oster]

Having the same issue front passenger side keep us posted what u find out

[MaccyD]

Also BC, also front passenger side lol. Doing a nut and bolt check i mullered up a few and it seemed to improved. Did you use the supplied adjustable drop links? My suspicion is it could be that the ball joints on them is toss. Or the design in general. I had to question when they didnt put an opposite thread on one end so it could be adjusted without being removed. I may try chucking the old drop link on.

Weird thing tht we all have it passenger side though!

[simmo1985]

Originally Posted by MaccyD

Also BC, also front passenger side lol. Doing a nut and bolt check i mullered up a few and it seemed to improved. Did you use the supplied adjustable drop links? My suspicion is it could be that the ball joints on them is toss. Or the design in general. I had to question when they didnt put an opposite thread on one end so it could be adjusted without being removed. I may try chucking the old drop link on.

Weird thing tht we all have it passenger side though!

+1 regarding drop link being the issue.

Had same with my front passenger side. I changed over to non nylons nuts and used washers and then tightened as much as I could,also used threadlock glue to ensure it stayed tight.All was great until the ball joint went on the front left link.

[telewebby]

Ive also had this issue, all bolts checked by several garages, even watched 1 do it, car drives fine be interesting to find out what it is

Alex

[MaccyD]

Ill stick the old drop links on and see if theres any difference

[joeyt]

My friend had bc coil overs on his e30 325. I know its two different cars but he also had a knocking like a top mount had gone. It turned out after allot of fiddling that it was the "bearing" in the solid too mount. Apparently they can do it from time to time. Luckily they replaced them for him. So could be that. Its worth asking

[AzRiz]

I also have the noise from front left! When I tighten the droplink, it goes away for a day or 2 until it loosens and knocks again. I'm really surprised to see so many people all with a noise from the passenger side!

[gaza01]

Guess what...yep. I have the knocking on front left side!

[MaccyD]

Has anyone compared thread length of new vs old spherical joints? I noticed the knock the day after fitting so i took the wheel off to do a tightness check on everything. I noticed there were rub marks on the bit of wheel arch trim by the lower drop link.

I just cant believe its damper related if we are all getting it on the passenger side. And it also can really be the spherical joints specifically, else we would be hearing it both sides. It has to be something to do with the design of the car that maybe isnt symmetrical left to right.

I dont suppose anyone who has had this problem for a while fancies have a good look underneath to see if they have bee catching on anything?

[imygaf]

Anyone else having this problem please post here. Im going to forward this thread to BC and hopefully get a solution.

Its already cost me £100 trying to sort this and now im going to pay for another couple of days labour for replacing the damper and investigation so im not happy. If id known this i would have just spent the extra for a different brand.

[J2S2M]

BC's coilovers are notorious for clunking, rattles, and other noise issues. You should do more research before spending your hard earned money on big price tag items. IMO your best bet is to contact the manufacturer to see if they are willing to replace them under warranty.

[Rudz]

Originally Posted by J2S2M

BC's coilovers are notorious for clunking, rattles, and other noise issues. You should do more research before spending your hard earned money on big price tag items. IMO your best bet is to contact the manufacturer to see if they are willing to replace them under warranty.

Getting a replacement is fine but the 4.5 hr labour u get charged for swapping suspension out and the time ur car is off the road is where u get hit?

[Gazza0210]

I've been planning on getting a set of Bc's for a while now.

All i've seen is good reviews on the interweb about these but its definitely making me second guess now.

Does everyone have this issue with the Bc's or is it just limited to a few of you guys.

The last thing I wanna do is spend a load of cash on some coilovers that don't stop knocking.

I might be completely barking up the wrong tree but would it not be worthwhile sticking with oem droplinks rather than the aftermarket ones you get with the kit.

[rhysh1990]

I was about to take the plunge and buy some BC coilovers pay day, not too sure now though the knocking will drive me insane. Has anyone had the knocking issue with other coilovers

[Josh1a1h]

I am speaking with the guy who has designed these coilovers and hopefully he will give me an answer shortly.

I have a similar knocking noise but i put it down to my drop links being incorrectly adjusted

Mine only clunks on uneven, side to side roads which make you hit your head on the window haha


How to adjust drop links correctly
http://forums.m3cutters.co.uk/showthread.php?t=16128

[M4rius]

Looks like it's not BC's fault. I've got FK's and passenger sides drop link keep getting loose (bottom nut).
I've tried everything and nothing worked, after 2-3 weeks it getting loose and start to clunk. This weekend fitting locking washer and hope it will solve the problem.

[AzRiz]

Originally Posted by M4rius

Looks like it's not BC's fault. I've got FK's and passenger sides drop link keep getting loose (bottom nut).
I've tried everything and nothing worked, after 2-3 weeks it getting loose and start to clunk. This weekend fitting locking washer and hope it will solve the problem.

Yup, bottom adjuster nut for me also.

Looks like we all need a better adjustable droplink product for this platform.

[MaccyD]

As has been mentioned, its a bit crazy to assume its BCs fault (with the damper at least) when you consider we are all only getting it on the passenger side front. If everyone had knocking from all over the place i would point the finger at BC but it doesnt seem to be that way.

Incidentally, in the thread Josh put up they seem to go mental for unclamping the ARB. I dont see why this is the case. Surely you adjust the drop links to account for the lowered height OR you put the drop links the same length and then just loosen and tighten the ARB clamps once it has settled in a new position (seems completely wrong as youre losing the designed mechanical advantage).

I messed up on mine and didnt think so shortened the drop links when i should have lengthened them. Heres my plan (chime in if you think im wrong!!):

1 - Unbolt both lower drop link mounts.
2 - Drive up on bricks/wood for clearance under car
3 - By hand, reach behind the wheel and adjust the drop link so it freely moves into the lower arb hole.
4 - Tighten mount bolt
5 - Jack up and tighten up the lock nuts

This should put your ARB in a completely neutral position at whatever your ride height is.

[achu]

just another +1 for the clunking... i've grown to live with it... might just move onto another brand before the warranty finishes (get them replaced and sell them on)... i hear D2 are good...

[Josh1a1h]

Originally Posted by MaccyD

As has been mentioned, its a bit crazy to assume its BCs fault (with the damper at least) when you consider we are all only getting it on the passenger side front. If everyone had knocking from all over the place i would point the finger at BC but it doesnt seem to be that way.

Incidentally, in the thread Josh put up they seem to go mental for unclamping the ARB. I dont see why this is the case. Surely you adjust the drop links to account for the lowered height OR you put the drop links the same length and then just loosen and tighten the ARB clamps once it has settled in a new position (seems completely wrong as youre losing the designed mechanical advantage).

I messed up on mine and didnt think so shortened the drop links when i should have lengthened them. Heres my plan (chime in if you think im wrong!!):

1 - Unbolt both lower drop link mounts.
2 - Drive up on bricks/wood for clearance under car
3 - By hand, reach behind the wheel and adjust the drop link so it freely moves into the lower arb hole.
4 - Tighten mount bolt
5 - Jack up and tighten up the lock nuts

This should put your ARB in a completely neutral position at whatever your ride height is.

That is the way to do it isn't it? That's how i was thinking of doing it.

Originally Posted by achu

just another +1 for the clunking... i've grown to live with it... might just move onto another brand before the warranty finishes (get them replaced and sell them on)... i hear D2 are good...

D2 are stiff... BC are of a very gd design. Especially for people who want to go low.

Only issues are these drop links. They need some blue loctite on them? Or a secondary bolt to tighten up against the primary bolt?

[J2S2M]

Originally Posted by achu

just another +1 for the clunking... i've grown to live with it... might just move onto another brand before the warranty finishes (get them replaced and sell them on)... i hear D2 are good...

BC's, D2's, Ksport, etc are all rebranded made in China cookie cutter coilovers. There are more reputable coilovers available such as the ST's. They have a rebate currently which would bring the price to about $740 after rebate. Even though they don't offer damping adjustability, they are far more superior than the chinese coilovers w/ little to no R&D behind their products.