bc coilovers making thud noises over minor ridges/potholes - any advice what to check
 

just need to know as my bc coilovers br series on left side are making some horrible thud noises while going over only minor ridges/pot holes.

any ideas what i can check myself? going to have a look today before work?

I only recently changed them from 27 from hard to 18 from hard in the last week and upped my winter tyres pressure to 40psi.

on the way home this morning dropped psi to 25 but still getting 'thuds' on the left side only.

If it's not the anti roll bar links or bushes, then maybe the BC top mounts, BC's are known to knock. But it could at a push be a drive shaft, although this is more on and off of power.

Thanks
Sam

From history the BC`s are known for it.

Mine are also doing it on the left rear too. So I will be interested to see how you get on. As soon as I iron out post rebuild niggles it's going up to BC for them to look at it.

Are they adjustable rears or std rubber top mounts?

mine used to do it awsell.hence why i'm now running teins again.

Mine are adjustible solid top mounts.

thx for all tips, i will check everything when i get a day off work.

Anyone recommend a good suspension garage? I don't mind travelling for the right place.

rickya - "Are they adjustable rears or std rubber top mounts?" Not sure as they were on the car when i bought it. The car was mega low when i got it - ie rear arches rubbing on cornering, front wheels catching on arches before you get full lock. so a few months back i raised the rear suspension by 1 inch. The previous owner also had put on 18x8 wheels but I now have my winter wheels on that are 18x7.5 which made a good difference - no more rubbing on tyres.

It feels like one of the shocks has died, as even minor dips in road where theres a small damage to tarmac u feel a good bang through the car on that side.

I've had the spring twang before after hard cornering.

Did you check top mounts screws.Since they are metal and if not fully tightened mouts might hit agains chassis,metal on metal sound. I have RM series with fully adjustable top mounts and mine knock only when hitting some major pot hole which is understandable.

I would change the rears top mount section to std rubber ones and see If it improves.

beliblisk - yes I checked top mount bolts and all are tight on all 4 sides. Its only recently about a week after adjusting them to 16 clicks from soft that it started happening.

I have just gone now to 7 clicks from soft on all 4 corners and it has improved a little. I also removed front upper strut brace today that i fitted a few weeks back, i'll see if it improves on the way to work today.

rickya - thx for the tip but I think I'm best taking it to a garage to have a look at.

The rear strut top adjusters have remote adjusters, could one of these be bad and so maybe set on hardest setting constantly?

If you feel a click as you adjust then they are fine.

Have you checked the bottom mounts? the spring seat and preload, etc.

Rubber mounts use a conical spring not a parallel one, but Apex have all these in stock.

I'm thinking its the front passenger side shock as when you press down on car and release its really very firm, no bounce at all.

Markyscoob - yeah i can feel a click when adjusting. I've got a mechanic friend coming round tomorrow to have a look, i will mention bottom mounts, the spring seat and preload, etc. cheers

just looked today and theres alot of oil around area of strut so looks like it needs a rebuild.

thx to all that replied for the help.

Sorry to bump such an old thread, but thought I'd chip in.

This has been happening to mine from day 1. I asked the guys from API to check and they said it's fine, but I still shudder when ever I hit a pot-hole. The bang is so loud. A friend suggested that perhaps the surface is hitting the rim? My tyre pressures are fine.

easy fix.

bin the cheap chinese sh1t.

stop eat and talking ****e
few forum members swap ast for bc and saying bc's are a lot better on road
last review which i read was from member with 537bhp hatch sti

Why does he have to stop eat???

'Cos he's Fat :lol1::lol1::lol1::lol1:

Maybe Flawor was telling his old mate Tubs to stop and eat. It's hard to know.

Mmmm, I can't really afford to throw them away. From a handling point of view they have certainly improved the car imo, it's just the pot holes... or even bumps in the road which sound like I've just driven over a curb... :(

ive had them and like your wrx they are cheap nasty sh1te.:thumb:

Really not helpful! I was asking a serious question.

its a serious answer they knock and bang due to being cheap chinese crap.
live with it or buy better quality coilovers

I don't for one minute believe that API would sell me 'cheap chinese crap'.

So, I'm presuming that the bang is not the road surface making contact with the wheel rim then?

Usually top mounts in my experience of bcs

OK, thank you. Can this be fixed at all?

I never found a cure,reset preload,checked,had geo done.
But to be fair coilovers aren't a great choice on the road no matter what make.
The biggest issue I found with bcs was they are silly bouncy even on softest setting on country roads.
OEM shocks and lower springs are a far better combo for the road.

OK :( thanks for that.

I have to agree with Tubs. This is why I stuck with OE shocks with decent lowering springs on my every day road car.

I have owned lots of cars road or race with coilovers and none were great on the road.