Is there a way to test if strut tops are faulty?

[Bainbridge]

57 plate Vauxhall Astra (H)

Annoying little rattle on uneven road surfaces. I've been underneath and had a good look, both with the car's weight on the wheels and without. Everything seems fine.

The noise is metal to metal and reminds me of worn anti roll bar links, but the existing ones had no detectable play. For the princely sum of £12.95 for both sides I changed them anyway, and sure enough the noise is still there.

My online research is leading to worn strut tops as a possible cause, but before I fork out a whopping £35 on a new set, and work out how to operate my father in law's home made spring compressor, is there a way to pin down whether it is indeed the strut tops?

Thanks

[stevieturbo]

ARB bushes.

And buy OEM, most aftermarket stuff is just ste.

[wyson]

I had this sort of noise as well. The mechanic thought it was anti roll bar links on the diagnosis drive, but it turned out to be the brake caliper.

It’s recently come back after I banged a wheel on a curb. Mechanic told me to wait until it got worse because he couldn’t see anything wrong.

[E-bmw]

As you know suspension rattles can be VERY hard to replicate & diagnose precisely what the cause is.

All I can suggest is that with the car weighted (probably on ramps or similar) you need to find a way of making the noise return.

This could be by having a burly friend rock the car as hard as possible while you are under it, or using a large prybar to move suspension rapidly while feeling around the movement etc.

These methods are applicable for any suspension part, just keep going until you find it.

[Demelitia]

Jack the car up, get it on a stand so the wheel is off the ground. Use a long pry bar with a small block of wood placed under the heel of the bar as it’s fulcrum point to lift the wheel and suspension up and down.
Do this at different speeds, to different heights whilst holding your hand on different suspension arms or components and you’ll be able to feel the knocking.

You can lower the car on the stand so it’s as close to ride height as possible after you’ve got the pry bar under the wheel so you don’t get a false idea of what the noise is.

I wouldn’t discount the damper being at fault; I’ve recently had to change the front axle dampers on mine after searching for a knock for a good long while.

Id narrowed it down to the top mount or damper, but the tyre wear that had started gave the culprit away just before I got around to changing them.
You’re looking for cupping/scalloping wear around the tyre if it’s the shock.

[Bainbridge]

Hi guys

Sorry for the late response, I've had so much on I forgot I'd created this thread!

Thanks everyone for your replies. The noise still remains and I'll need to get it sorted before the summer weather ends, so I follow some of the suggestions made here and report back in case it might help someone else.

[Bainbridge]

Update:

After 2 more sessions under the car and an assistant trying to replicate the noise, I still can't identify the rattle. I bought a set of top mountsv (£40), but the nut on the top of the damper has rusted away to a mound under the little plastic cap, on both front struts. The OH put the car in for MOT and it passed with 1 advisory for a worn tyre getting close to the legal limit, I was expecting advisories for 2 tyres. So I've bought 2 replacement dampers (£50) and will cut the dampers to remove the springs once I've removed the complete unit and compressed the spring. With the work involved in taking the strut out I should really be replacing the springs too, but I'm trying to keep costs down on this old car.

So I've spent £103 in parts to solve this rattle so far, once I've changed the dampers and top mounts I'll report back.

[Demelitia]

For what it’s worth, you could replace both front springs for £30 or possibly less.
It might be worth the satisfaction and peace of mind.

[Bainbridge]

Demelitia said:

For what it’s worth, you could replace both front springs for £30 or possibly less.
It might be worth the satisfaction and peace of mind.

I probably should, but the strut tops being the only cause of the rattle is only a guess, so I may have to end up buying another part to solve it if this doesn't work. Another thing going in my favour if a spring does break is the fact that replacement will be simple because I know everything can be easily dismantled.

[Bainbridge]

Update:

Annoying rattle cured, it was the top mount or damper!

OH is very happy, no more annoying noise, and for £103 it's not too costly. Plus I now have a bit more experience and a set of spring compressors.

@Demelitia

I should have changed the springs too because those top nuts which wouldn't undo have an interruption on the thread to make them undoable! This explains why I couldn't get the old bolts off, I thought it was due to rust. Old springs are in pretty good shape and I think that my use of the spring compressor contorted them way past their usual range, so hopefully they'll be ok until new car time.

Gotta keep the old girl running!

Edited by Bainbridge on Thursday 1st December 09:39

[buggalugs]

You often need random bits of rubber from the old strut too which never seem to come with anything specific and you sometimes can't seem to order them either!

Worn top mounts sometimes groan when going lock to lock too