problem unknown, help

Red_Beastie · May 30, 2011

when i pull away i get a knock from the front, when i change low gear i get the knock aswell like something is moving backwards as i pull away. after driving about 60 for a few mins the service trac light comes on. i know my suspension needs rebuilt but this wouldnt be the cause of it i dont think,

im thinking wishbone or bushes?

anyone had a similar problem?

hoolio · May 30, 2011

Red_Beastie said:
im thinking wishbone or bushes?

I don't think they would light up the service light, if the knock and light are connected maybe something to do with the exhaust?????

BenG · May 30, 2011

when i pull away i get a knock from the front, when i change low gear i get the knock aswell like something is moving backwards as i pull away.

Sounds like worn engine mounts? probably the lower (dog-bone) engine mount. Does this happen when you accelerate hard in 2nd gear?

I could be that the two are not related. I found that my SERV and traction control light would come on after a few miles and it turned out that my CV boot clip had come loose and was spinning around the ABS sensor.

Red_Beastie · May 31, 2011

to add to my problem i was driving home from work there and the wee red stop light and ( ! ) warning light was flickering, not all the time just flickered very quickly and faintly then went off again. did it a few times on journey home. help my wee car is sick

bearne1 · May 31, 2011

The 2 warning lights are most likely to be alerting low brake fluid. Mine does it taking bends on the fast side!

liam1610 · May 31, 2011

As stated by BenG check cv boot clips first, sounds like a clip has broken causing lights to come on, if its been like that for a while i have known joints to go dry and cause a knocking noise, if it was me clean the joint as best as possible then chuck some cv boot grease in the boot then put a new clip on it and see how it goes. If thats not the issue then jack each corner up and check for play top to bottom and side to side and just a general visual check of everything suspension wise.

As for the stop light coming on how often do you check levels? i would say check brake fluid level first i know that light comes on under movement when level is low.

Red_Beastie · May 31, 2011

should low brake fluid be an issue? i had a 206 for 10 year and nevr had to top it up once

liam1610 · Jun 1, 2011

Iv found mine seem to loose brake fluid from the cap, there is a seal for the level sender and its not a very good one. Its best to check it and takes 5 seconds. At least you can rule that one out then.

stormduck · Jun 1, 2011

I would guess engine mount. Knocking noise caused from a cv joint happens when turning on the move so the wheel's under lateral load. A knock when pulling away suggests the engine is shifting backwards and causing the manifold to knock on the heat shield.

Someone else may be able to confirm this, but i believe there's a chance if you pop the bonnet, grab hold of the top of the engine and pull it back and forth, you may be able to mimick the effect if the mount is worn enough.

btw, mine also used to lose a bit of brake fluid. I cleaned up teh cap and sure enough a while later their was fluid there again. A new cap from renault isn't dear and fixed the issue.

stormduck · Jun 1, 2011

low brake fluid could also be a sign of thin brake pads

liam1610 · Jun 1, 2011

A new cap fixed the issue sounds like you was lucky there then. As for moving the engine with your hands there is no way you can mimic the movement by hand, maybe a big pry bar would do the same kind of movement under heavy load.

As for cv joint if you think its just limited to turning movement your mistaken, if there is slack between the center splines on the joint and the shaft you will get a knock in a forward direction under load or switching from movement forward and back.

stormduck · Jun 1, 2011

liam1610 said:
A new cap fixed the issue sounds like you was lucky there then. As for moving the engine with your hands there is no way you can mimic the movement by hand, maybe a big pry bar would do the same kind of movement under heavy load.

Fair do's

As for cv joint if you think its just limited to turning movement your mistaken, if there is slack between the center splines on the joint and the shaft you will get a knock in a forward direction under load or switching from movement forward and back

Do you mean the splines into the diff/hub?

eljeffo64 · Jun 1, 2011

stormduck said:
low brake fluid could also be a sign of thin brake pads

+1 ^^

liam1610 · Jun 1, 2011

stormduck said:
Do you mean the splines into the diff/hub?

No i mean the splines on the shaft itself and the cj joint has spline in the center if either of these have worn its new drive shaft time. I will try find a picture and explain what i mean.

stormduck · Jun 1, 2011

oh okay i see, don't worry they're complicated little beggers them! I peeked inside the gaitor once and got scared...filled it with grease and covered it up again! :? In my experience i've only had them clonking when turning, but now i know.

liam1610 · Jun 1, 2011

Ok well if you ever need any help with a cv joint just ask, there really not that complicated but i have to admit it makes a right mess when fixing one and a tip is to make sure you wear gloves as it will take ages to get your hands clean after

Anyway back to the topic Red_Beastie let us know how you get on.

Red_Beastie · Jun 2, 2011

apparently the bottom ball joint was loose...

so its something worth checking regular i guess haha he said it was nearly off :O