Weird bump at low speeds

[Blubayou]

Hi all,

Car is a 2004 HDi 90 with 64'000 miles. I've had this problem since I bought it a couple of months ago.

Low speed tight R/H turns, usually in reverse but sometimes forward, the car bumps on the left front side just like I've gone up a low curb or over a small rock.

Following research on this excellent forum, I'm pretty sure the spring is winding up torsionally & then letting go with a twang causing the bump, presumably due to a broken top suspension bearing.

Am I on the right track?

Thanks in advance ,

Blubayou

[jasper5]

Very easy to check, get someone to start up the engine and turn the steering lock to lock whilst you watch the spring and see if it winds up as the steering turns.

[rwb]

That sounds familiar.

I'll add it to my list.

[Blubayou]

Ok, thanks Jasper. I'll let you know how I get on.

Incidentally, all other Macpherson strut cars I've done have had a proper roller bearing & rubber combo at the top.

The bearing in this case looks like a steel ring which sits against the top mount. Should it be lubed with something?

[Blubayou]

Hi all,

Just had a look at the action of the springs with the car on it's wheels & all seems to be moving fine. MOT next week so maybe something will be picked up there. Incidentally the car tracks badly on bad surfaces. The tyres are original spec Pirellis so unlikely to be the cause. I've rocked the wheels top to bottom & side to side & all seems fine.

See what the MOT throws up

[Blubayou]

Hi all,

MOT today & all is well.

I replaced the O/S front tyre yesterday as it was down to the minimum. An original spec 205/55 16 P6000 for £65 seemed a good deal so I went for it & to be honest it doesn't seem to track so badly over poor surfaces. I have a new pair of top mount bearings & will change them soon as I'm still suspicious that they are breaking up.

Other than that, here's to another years frugal motoring

[steve_earwig]

Splendid Was the old tyre unevenly worn? I'd have thought the tyre on the other side would be the same age so it's odd one wore out forst. Perhaps it had a broken belt and that's why the handling was odd.

When you change the bearings may I suggest you change the springs too while you've got the struts apart? Seems like it's only a matter of time

[Blubayou]

Well the other tyre is ok but down to around 3mm so will need doing soon. The tyre that was replaced looked ok but may well have been damaged, we have 3rd world roads here in the midlands. The poor tracking has definately gone and the car feels much better in a straight line now. £65 well spent!

Regarding the springs, I probably will swap them but I am a bit worried of reports about the car sitting too high. Bought springs for my Scirrocco from GSF a few years ago which made the front sit too high, ruined the look of the car. So if anyone knows of good springs at the right price please let me know.

Meanwhile the motor is going well, I'll try & post a pic