'Trundling sound' at speed

[Rantpaste]

Hi guys. So, I'm hoping this is an obvious problem that everyone knows about 406s because, you know, it would make my life easier ;)

Basically, as the car gets faster there is a 'trundling' sound that seems to come from the back of the car - it sounds like I'm towing a fixed-wheel trailer or something and starts at around 20-30mph. I say 'gets faster' particularly because it doesn't seem to be directly linked to acceleration, only speed. Further, as I get on the motorway it seems to go away when I'm pushing the speed limit, coming back louder as I slow down again. Maybe that's just perception.

It's been happening for about 3 months now and although nothing else seems obviously wrong I'm getting the feeling I'm not doing myself any favours. Thing is, having spent only £600 on the car I'm loathe to spend much more money on it ;) Any thoughts would be greatly appreciated. It's a V-reg 2.0 Lx Hdi, if that makes a difference.

[highlander]

Check your tyre pressure is 34PSI on all four wheels!

Lower-than-optimal tyre pressure can cause this droning noise, in addition to uneven and excessive tyre wear, and increased fuel consumption.

If the tyre pressures are all OK, then you should check to see if your rear wheels have any abnormal play in them (i.e. that might indicate the anti-roll bar droplinks or the tie bars being worn out).

If the wheels have any balancing weights on them, see if any of them are obviously missing (as being out of balance can cause vibrations (which is all sound is, after all)).

Hope some of this helps you find your culprit!

[steve_earwig]

I'll just add knackered shock (bouncy bouncy) or a deformed tyre (jack it up & spin it)

[Rantpaste]

If the wheels have any balancing weights on them, see if any of them are obviously missing (as being out of balance can cause vibrations (which is all sound is, after all)).

I'm thinking I might go get the wheels balanced - the last tyres were fitted by kwik-fit and I think the problem started around then. Pressure is fine.

I'll just add knackered shock (bouncy bouncy)

If it's this, how much am I looking at for replacements? I could probably fit them myself (or get my brother to do it). EDIT: GSF reckon £37.50 for each of the shocks, same for the springs. Sounds reasonable to me.

[dummysock]

I would check to see if the brakes are binding, particularly the handbrake

[grasmere59]

We had a van year old Peugeot Expert van at work that made that sort of noise and it turned out to be a deformed rear tyre.

[Doggy]

I've had the same symptoms, turned out to be a bulge in the tyre, but couldn't see anything until I took it off.

Try swapping your two rears in turn for the spare, takes a little while, but it is cheap!