General Loud noise & vibration when raining heavily PLEASE HELP

[Nova1734]

My 2009 car does this every time it rains heavily and the road has pooled water. It seems to start at the left rear part of the car and it gets so nerve-wrackingly loud it's incredible, vibrations all around the cabin. It's genuinely so scary.

Doesn't happen in dry weather or when it's slightly wet, only heavy rain/very wet road surface. Seems to also happen when water gets sprayed on that side if I'm overtaking a lorry for example.

Only happens when I'm driving 50+mph, the sound seems to quiet down when I slow down. The cars been through at least 3 mechanics, all can't find an issue with anything. Tyres, wheel bearings, alignments, suspension is all fine.

I did see another post for a Panda where a similar sound was coming from the rapid cooling of the exhaust, could it be this?
Is it safe to drive, what's the worst that could happen if the exhaust is rapidly cooling due to the water?

 

[jrkitching]

I did see another post for a Panda where a similar sound was coming from the rapid cooling of the exhaust, could it be this?

Not if the exhaust is properly supported. If any of the exhaust mountings are defective, then it's possible.

The most important one to check is the one at the front that secures the bottom of the catalytic converter to the gearbox housing. These can corrode away completely, leaving the whole exhaust system, including the cat, supported at the front only by the exhaust manifold. This quite often causes the combined manifold/cat to fracture. Replacing the manicat won't be cheap, and the repair is often complicated further if the studs in the head are either broken by the excessive flexure or are just corroded into place.

All avoidable by changing the bracket once it starts to look corroded. Replacement brackets are easy to source online. If just replacing the bracket, it's possible to open it out sufficiently to slip it onto the bottom of the cat downpipe.

On a 2009 car, unless it's been replaced, this bracket may by now be completely missing.

It's a reasonably well known issue on the 500 (and the Panda).

 

[varesecrazy]

This was mentioned before..

Worth using SEARCH in advanced

 

[jrkitching]

This was mentioned before..

Worth using SEARCH in advanced

Were you thinking of this thread?

Excessive vibration is sometimes reported on TA engined cars (usually a sign of impending DMF failure), but that's a red herring in this case, since the OP's car is 2009 and can't be a TA.

 

[varesecrazy]

No, it was a wet weather scenario..
I will look later

 

[jrkitching]

No, it was a wet weather scenario..
I will look later

There's this one which was an almost brand new 1.2 Panda.

Turned out to be a major engine problem; Fiat only offered to repair, not replace the engine under warranty - so the OP (successfully) rejected the car.

Given that the OP's car is 14 years old, I doubt this is the cause here.

 

[varesecrazy]

In my mind..
It was 12 /18 months ago,

I will look later when I have 20 minutes..

 

[Nova1734]

Not if the exhaust is properly supported. If any of the exhaust mountings are defective, then it's possible.

The most important one to check is the one at the front that secures the bottom of the catalytic converter to the gearbox housing. These can corrode away completely, leaving the whole exhaust system, including the cat, supported at the front only by the exhaust manifold. This quite often causes the combined manifold/cat to fracture. Replacing the manicat won't be cheap, and the repair is often complicated further if the studs in the head are either broken by the excessive flexure or are just corroded into place.

All avoidable by changing the bracket once it starts to look corroded. Replacement brackets are easy to source online. If just replacing the bracket, it's possible to open it out sufficiently to slip it onto the bottom of the cat downpipe.

On a 2009 car, unless it's been replaced, this bracket may by now be completely missing.

It's a reasonably well known issue on the 500 (and the Panda).

Thank you so much for the detailed response!
Is this not something that's checked by mechanics when the car is serviced at all? Just curious because none of the garages I've taken it to seem to know what to do with it after I explain the issue, just a bit of head scratching and confused looks is what I get.

 

[jrkitching]

none of the garages I've taken it to seem to know what to do with it after I explain the issue, just a bit of head scratching and confused looks is what I get

You can see and photograph the front support bracket from under the front of the car. If lying on the ground in the current weather conditions doesn't appeal to you (and I can completely understand that!), you might be able to get a phone on a selfie stick down there. If you can get a photo of your own car, we can advise on the state of the bracket.

Here are a couple of pictures; the bracket in the first had seen a little over 10yrs service; the second photo shows its replacement.

 

[Nova1734]

You can see and photograph the front support bracket from under the front of the car. If lying on the ground in the current weather conditions doesn't appeal to you (and I can completely understand that!), you might be able to get a phone on a selfie stick down there. If you can get a photo of your own car, we can advise on the state of the bracket.

Here are a couple of pictures; the bracket in the first had seen a little over 10yrs service; the second photo shows its replacement.View attachment 434441

View attachment 434442

Thank you again!
I've taken the car to the garage this morning so hopefully they'll get it back to me on Monday and I can get a picture for you! The guys looked underneath and said all is perfect including tyres, bearings but will look at wheel alignment in an attempt to fix. Said hes taken it for a ride and didnt hear anything wrong with it. Apparently the car is fully road worthy.

I'm just wondering, could this really be the culprit? The noise and vibrations seem to come from the rear left hand side and if this bracket was damaged or missing, wouldn't the noise be present in all conditions not just heavy rain/wet roads?

 

[jrkitching]

I'm just wondering, could this really be the culprit?

It probably isn't, although it could be.

But it's quite likely this bracket will need replacing on an older car, even if it's unrelated to the problem you're currently experiencing.

 

[Nova1734]

It probably isn't, although it could be.

But it's quite likely this bracket will need replacing on an older car, even if it's unrelated to the problem you're currently experiencing.

I've actually just fished out some of the service history paperwork and I had the rear suspension, middle and rear exhaust replaced, replacement bracket from cat to gearbox was included on there with rear springs and shock absorbers. Had it all done in 2020.

 

[jrkitching]

I've actually just fished out some of the service history paperwork and I had the rear suspension, middle and rear exhaust replaced, replacement bracket from cat to gearbox was included on there with rear springs and shock absorbers. Had it all done in 2020.

Probably unlikely to be an insecure exhaust then.

That said, some of the aftermarket exhausts I've seen are of such poor quality that I wouldn't expect them to last more than 2-3 years.

 

[John202020]

Check all, plastic arch liners, any plastic part and all it's fixings, like the rear bumper lower fixings anything that could be affected by pounding water? Any part that's not fixed correctly like the hand brake cable ?

 

[Nova1734]

Check all, plastic arch liners, any plastic part and all it's fixings, like the rear bumper lower fixings anything that could be affected by pounding water? Any part that's not fixed correctly like the hand brake cable ?

Hiya, the entire underbelly of the cars been checked and the mechanic said everything's as it should be. Had the hand brake cable redone this September but the problem has been longstanding for the last 2-3 years.

I've been told it could be due to an ABS issue? Where apparently the left wheel is going slower than the other and the water might be affecting the speed indicator or something? Just a mates suggestion so unsure if it's got any merit. What do you think?

 

[varesecrazy]

Hiya, the entire underbelly of the cars been checked and the mechanic said everything's as it should be. Had the hand brake cable redone this September but the problem has been longstanding for the last 2-3 years.

I've been told it could be due to an ABS issue? Where apparently the left wheel is going slower than the other and the water might be affecting the speed indicator or something? Just a mates suggestion so unsure if it's got any merit. What do you think?

Not impossible..
But would anticipate a dashboard light when the ABS was being triggered?


So IF its been a thing for 2 or 3vyears...

Have the tyres moved around it that time?

 

[Nova1734]

Not impossible..
But would anticipate a dashboard light when the ABS was being triggered?


So IF its been a thing for 2 or 3vyears...

Have the tyres moved around it that time?

Nope, no lights at the dash. All tyres were replaced and adjusted in September 2022.

 

[varesecrazy]

I looked for a similar post.. But couldn't find it .

So back to the detective work..

 

[varesecrazy]

My 2009 car does this every time it rains heavily and the road has pooled water. It seems to start at the left rear part of the car and it gets so nerve-wrackingly loud it's incredible, vibrations all around the cabin. It's genuinely so scary.

Doesn't happen in dry weather or when it's slightly wet, only heavy rain/very wet road surface. Seems to also happen when water gets sprayed on that side if I'm overtaking a lorry for example.

Only happens when I'm driving 50+mph, the sound seems to quiet down when I slow down. The cars been through at least 3 mechanics, all can't find an issue with anything. Tyres, wheel bearings, alignments, suspension is all fine.

I did see another post for a Panda where a similar sound was coming from the rapid cooling of the exhaust, could it be this?
Is it safe to drive, what's the worst that could happen if the exhaust is rapidly cooling due to the water?

I was doing mway trips in mine this weekend, it is noticeably louder in Wet weather..
Certain sections of road worse that others... The note changes as you cover the miles

But it's generally only the rear corner..

I thought initially it was a wheel bearing.. But now realise it's dependant on wet roads


Your car is from the 1st year of production..

Always s chance its had an issue.. Either generated by @10 owners..
Or a factory thing that got fixed
(mine is 10 years newer..)

 

[Nova1734]

I was doing mway trips in mine this weekend, it is noticeably louder in Wet weather..
Certain sections of road worse that others... The note changes as you cover the miles

But it's generally only the rear corner..

I thought initially it was a wheel bearing.. But now realise it's dependant on wet roads


Your car is from the 1st year of production..

Always s chance its had an issue.. Either generated by @10 owners..
Or a factory thing that got fixed
(mine is 10 years newer..)

I got it in November 2019 @56k miles, and I believe it only had one owner previously.

I don't remember it making this sound before the exhaust replacement in 2020 so perhaps there's something that's gone awry with the installation or something but I'd have expected it to have been picked up by major services/mot.
However I also didn't get to drive it much before all the lockdowns started and the rest of 2020 so the issue could've been there before the exhaust replacement and I just wasn't hitting the right conditions to trigger it.

In half a mind to push it next time it happens and pray that something breaks so that at least it can get fixed but the thought of potentially losing control of the car on the motorway makes my skin crawl with fear.