Technical loud bang front suspension over speed bumps

[wishbone1408]

Hi to all
I purchased a panda 4x4 1.2 on a 2007 plate about 7 months ago. Upon collection the seller gave me an invoice stating the car had recently had 2 new front shockers
replaced, I looked underneath and there were 2 new shiny shocks. I then drove 120 mile down the motorway and everything seemed fine until I got closer to home
on local roads, I noticed a loud bang from the front when going over speed bumps and potholes, the noise is so loud I almost jump out of my seat.
The following day I drove over speed bumps on each wheel independently and the problem is certainly on both sides. the noise does not occur when the front wheels hit a speed bump, its when the front wheels leave the speed bump, if that makes sense, in other words the loud bang occurs when the shockers are retracting but not whilst compressing.
I had it checked out at a garage and they could not find anything wrong, ball joints, track rod ends, drop links, and bottom arms were all Good.
A few months later I took it to a different garage as the mot was dew and explained the problem. when I went back to collect, the mechanic said my car had passed its test and could not identify the problem, but he did say he suspects the new shockers that were replaced prior to me buying the car maybe the wrong type, but he was not sure, which leaves me a bit stuck as if I buy new shocks it might not cure the problem. According to the invoice the shocks are NEOX GAS SHOCKS, any Good advice on this would
be greatly appreciated, thanks, John

 

[varesecrazy]

Hi

The top half is 'loose' within the inner wing..
With a steel 'cupped washer' that stops the whole thing falling through the wing

Potential issues..

Maybe the gap between the upper bearing and that retaining cup is too large.. so there is a Thud when the Damper 'dangles'as the weight of the car comes off it


Noise..
Of course the 'droplinks' are on either end of the Antiroll bar' so the front suspenion isnt truly independent

 

[wishbone1408]

Hi

The top half is 'loose' within the inner wing..
With a steel 'cupped washer' that stops the whole thing falling through the wing

Potential issues..

Maybe the gap between the upper bearing and that retaining cup is too large.. so there is a Thud when the Damper 'dangles'as the weight of the car comes off it


Noise..
Of course the 'droplinks' are on either end of the Antiroll bar' so the front suspenion isnt truly independent

Hi
Thanks for the info and I agree there is certainly some excessive play somewhere at the top, another test I did was place both hands under the wheel arch and lift up Sharpley and there is a light clunk sound at the top on both sides which is amplified whilst hitting speed bumps and potholes, could it that whoever fitted the new shocks have installed them incorrectly i.e should the mounts be positioned in a certain way before re-attaching the suspension strut?

 

[Marcus Daly]

You might get more of a response in the right forum. This one’s for Pandas 2012-on.

 

[Panda IIs]

Hi
Thanks for the info and I agree there is certainly some excessive play somewhere at the top, another test I did was place both hands under the wheel arch and lift up Sharpley and there is a light clunk sound at the top on both sides which is amplified whilst hitting speed bumps and potholes, could it that whoever fitted the new shocks have installed them incorrectly i.e should the mounts be positioned in a certain way before re-attaching the suspension strut?

It seems you are suspicious of the top mount attachment and the symptoms seem to support that? It's feasible that the new shocks included the spacers and washers that go into the top mount (7&8) below (by the way I don't know if this is the correct diagram for your model but it is 4x4 however the principle will be the same) and these were incorrect;

Also if there is a Nylock nut (part 6 here) then it is possible that it was not fully tightened due to rotation of the shock, there is a flat (or hex - allen type) on the top of the shock shaft that should be held while tightening the nut; this precludes the use of a socket for the final tightening - but the fitter (if he had any experience should be across this). If you can jack the car up to get front wheel off the ground and then lever up wheel while watching the top mount (tricky without an assistant) then you should be able to check this visually. Use an axle stand as a precaution to anything falling off the jack!

The fact that it is both sides means either an improper installation or just not the right shocks...

 

[portland_bill]

The pic above is for the earlier, classic Panda, model 141. The original post is for teh 2003-2012 model, 169, where the top of the shocks are not fixed, relying on the weight of the car to keep them in place.

With the 'floating' top mount, the large washer, item 9, prevents the strut from falling out, but should usually only hit the car body if the wheels comeoff the ground, such as going slightly airborne over a fast bump.
If it is hitting on normal bumps, either they are being taken way too fast, or the shocks are too short, or perhaps the damping is too stiff on rebound, not allowing the shock to extend as the wheel drops.
To check if this is the cause of the noise, put a little blu-tack between the washer and body, with the car sitting normally. Not a big blob, just a thin amount. First bump should be a little quieter, and the blu-tack will be squashed.
Another possibility is that the top mounts (item 5) are collapsed, but I would have expected them to have been renewed when the struts were changed, but possibly not. When in the car, the struts should be towards the rear of their mounting hole in the body, not the front. They sometimes get fitted the wrong way around.
Item 8, the top spring mount has a tab, that should be positioned in only one place. Perhaps the springs are not seated correctly.
The struts need to come off, and be inspected by someone who has seen these before, and knows how they look.

Front shocks are different on the 4x4. Check the ones fitted, are they 4x4, or standard?

Fiat Panda II (04 to 09) 1.2 8v Shock Absorbers

www.shop4parts.co.uk

 

[irc]

As @portland_bill says above, but with 2 other slight possibilities which I have seen:

1 - is incorrect buffer fitted to struts. Bad ones can make a surprising amount of noise. Will need disassembling and replacement.

2 - is the stepped nut not fitted tight enough, (which looks OK, but leaves play in the strut, leading to a bang over bumps.)
Seen this on a few Pandas which had dampers changed by garages which should know better... quick check is to use an impact gun through the hole in the inner wing. If it tightens, re-fit the plate and nyloc and take for a short test drive.
If the noise disappears or reduces significantly then it proves the point.
Will need disassembling and correct reassembly.

 

[wishbone1408]

As @portland_bill says above, but with 2 other slight possibilities which I have seen:

1 - is incorrect buffer fitted to struts. Bad ones can make a surprising amount of noise. Will need disassembling and replacement.

2 - is the stepped nut not fitted tight enough, (which looks OK, but leaves play in the strut, leading to a bang over bumps.)
Seen this on a few Pandas which had dampers changed by garages which should know better... quick check is to use an impact gun through the hole in the inner wing. If it tightens, re-fit the plate and nyloc and take for a short test drive.
If the noise disappears or reduces significantly then it proves the point.
Will need disassembling and correct reassembly.

Hi
The First garage I went to did slacken then re-tighten the step nuts with an air impact gun but made no difference.
As it could be a number of things, I will try to find a Good mechanic that will have a proper look, maybe take the suspension legs off and check parts are assembled correctly. thanks for your advice

 

[wishbone1408]

The pic above is for the earlier, classic Panda, model 141. The original post is for teh 2003-2012 model, 169, where the top of the shocks are not fixed, relying on the weight of the car to keep them in place.
View attachment 421540

With the 'floating' top mount, the large washer, item 9, prevents the strut from falling out, but should usually only hit the car body if the wheels comeoff the ground, such as going slightly airborne over a fast bump.
If it is hitting on normal bumps, either they are being taken way too fast, or the shocks are too short, or perhaps the damping is too stiff on rebound, not allowing the shock to extend as the wheel drops.
To check if this is the cause of the noise, put a little blu-tack between the washer and body, with the car sitting normally. Not a big blob, just a thin amount. First bump should be a little quieter, and the blu-tack will be squashed.
Another possibility is that the top mounts (item 5) are collapsed, but I would have expected them to have been renewed when the struts were changed, but possibly not. When in the car, the struts should be towards the rear of their mounting hole in the body, not the front. They sometimes get fitted the wrong way around.
Item 8, the top spring mount has a tab, that should be positioned in only one place. Perhaps the springs are not seated correctly.
The struts need to come off, and be inspected by someone who has seen these before, and knows how they look.

Front shocks are different on the 4x4. Check the ones fitted, are they 4x4, or standard?

Fiat Panda II (04 to 09) 1.2 8v Shock Absorbers

www.shop4parts.co.uk

Hi
Thanks for your informative advice I will certainly try the blue tac test. I don't think the mounts got replaced with the shocks as the invoice I have states only 2 shockers. when you mention the front shockers are different on the 4x4, well that was my thought initially, so I typed in the details of my car on ebay and it stated the front shockers shown were compatible with my car, I then changed the details to a front wheel drive panda and it also stated compatible,. At First I did question myself about the speed I go over bumps as this is the First fiat I have owned and driven and thought maybe its normal for this type of car, but the noise is quite loud even at slow speeds, I have figured out it seems to be the shape of the speed bumps, the ones with a more gradual radius are fine, its the ones that have more of a step that causes the bang, the same goes for potholes,
another example is a certain roundabout local to me when turning left coming off the roundabout there's a small more like a dent rather than a pothole
which I hit every time and it makes the same bang, its exactly how you describe when the wheels become airborne that's when it occurs.

 

[vexorg]

If the lower arms are the same as the 500, I'd double check the bushes at the subframe side.

 

[portland_bill]

If the lower arms are the same as the 500, I'd double check the bushes at the subframe side.

That's why this forum is so good, others add to initial thoughts, giving a more complete answer.

There's so much that can make noise, rather than take bits off to check, it needs the whole suspension setup to be checked by someone who has worked on these before.
The rear bush on the bottom arm perishes, and can hide its deterioration well. Get a helper to watch a front wheel, then move forward and back a bit, half a metre should be enough. When moving off, or when stopping, the wheel should not move significantly forwards or backwards. If it does, the bottom arm rear bush is shot. Bushes are replaceable, but a complete arm is better, as it replaces both bushes, and the bottom ball joint.
The anti-roll bar links can also hide any play well, making quite a clonk from a small joint, and show no play when prodded. Once removed, the play will show. They are cheap, quick and easy to replace, and have a short life.

 

[vexorg]

They are cheap, quick and easy to replace, and have a short life.

Sometimes quick, sometimes needs a grinder as the thread is rusted and the whole thing spins with no means of holding the ball part.

 

[portland_bill]

Sometimes quick, sometimes needs a grinder as the thread is rusted and the whole thing spins with no means of holding the ball part.

Quite true, but made me smile. Usually they start knocking well before they've seized on. Unless the knocking has been ignored for some time of course. Or have I just been lucky with removal, or unlucky with their lifetime?

 

[Pugglt Auld Jock]

Sometimes quick, sometimes needs a grinder as the thread is rusted and the whole thing spins with no means of holding the ball part.

If you press the rubber boot away from the strut/anti roll bar, you'll find there's a narrowish parallel shoulder which you can get a grip on with something like a footprint or stilson wrench. I've had considerable success holding it from spinning in this way but here are times when an angle grinder is invaluable. If you have an air hammer you can partly split the nut on one side and then chase it round with the impacts. Nut splitter works too. Lots of techniques you might try.

 

[vexorg]

One car, cant remember which, had a square hole and square part at the bottom of the thread, always thought that was a great idea. The hex/torx ones in the middle of the bolt part tend to round of the nut is too tight.

 

[The Panda Nut]

Check that the gaitor is attached to the bump stop. If not the plastic lump at its top can make an incredibly loud bang over bumps. This is quite out of proportion with expectations. I and at least 1 other have suffered from this and it requires parts that clip together properly. A lot dont!!