Does anyone have a photo of the underneath of their car that they could share?

I recently had my 2009 (59) 1.2 Lounge put through the MOT at a small workshop and they failed it on a rusted 'flexi-pipe' and replaced it.

Fast-forward 2 weeks and I take the car for a longer run (only the 2nd time the car has been driven since the work) and there's a randomly occuring knocking noise coming from underneath, especially on bumps, or (for some reason) faster /longer corners, especially motorway slip-road style corners.

I took a look under the car to try to figure out what was wrong, but there was nothing obviously loose. The new exhaust flexi-pipe was obvious, as was the 4foot long new exhaust pipe leading from the flexible joint back to the backbox.

The new pipe did seem to be hanging quite a distance from the chassis and I'm wondering if they fitted the wrong part? There's a 'tunnel' in the chassis and I'm wondering if the exhaust is supposed to run tucked up into that tunnel or not?

The new pipe didn't seem to be loose - but obviously as it's hanging from rubberised supports maybe it can move around a bit and hit something?


Associated question - can anyone recommend a Fiat500 knowledgeable garage in South London? Either a main dealer who still has good mechanics, or an independent with a good reputation?

Our 1.2 2009 needed a new flexible as it's part of the "centre " pipe, the one that runs all the way to the back box, I 'simply, not ' replaced the whole exhaust, so it comes in two parts only, back box and centre, there are some that come in 3 parts but I don't think it's compatible, you could be right.
Grab with a rag if you don't want to get dirty the end and rock it about to see where the noise is ? I had a similar issue of knocking but found where it was and fixed it.

Get the car up on ramps, do you have a set of ramps? if not worth investing as they will pay there way for years to come. Up on ramps and you will be able to see things up close. Simple

Just took these two pictures they're not great but may help

Looking from the side the exhaust hangs about it's diameter lower than the box sections, that may be just a bit lower than factory middle pic is looking towards the front you can just see the pipe clamp bolts
Note my exhaust has been painted with black VHT paint so it's harder to see, and I can't remember why I put a cable tie on the pipe hanger rubber

Hi,

It is difficult to understand from what you write as it implies you are seeing a separate flexipipe at the front then an added length of exhause pipe fitted after that. For sure you can buy small flexi joints of various diameters and lengths but the Fiat original and the aftermarket one we fitted the flexipipe was actually all part of the same pipe from the catalyst or rear engine flange.

Whilst ours was a 1.4s so had the center pipe additional silencer box instead of just a standard pipe length they are for the rest of the system similar.

Again the original is just two parts but aftermarket ones often are in 3 sections and this is purely to keep shipping costs down as the correct original system from after cat/flexi +pipe up to rear silencer box is quite a long section and means most carriers will either not ship them or charge twice as much.

You need to find out what was fitted and if correct part or one just made up by a local garage to fit. There is a hanger bar attached to the centre pipe and ones further back and then two at the rear of the silencer box which are very difficult to see and easy to slip off when taking the system apart.

It would probably help more if you could put up some pictures of what you have so we can see yours.

The exhaust hangers are a twin hole figure of 8 sort of design and again the original ones have loosely fitted cloth/nylon band around the circumference which allows for some extension but puts a limit on the stretch. I really don't know the technical reason of the design of the original and if it is to limit the stretch or possibly add a safety should the rubber hanger perish (which they do). The after market ones that came with my system did not have the band around and the originals looked OK so I just reused the originals. i would assume maybe why John put the tie strap around but for sure the idea of the rubber is to give some movement in both directions.

All that said the fitting of the system at the rear end was quite a fiddle to set it up to give an even gap all around where the silencer box pipe goes up near the rear beam so I would suspect it would be the first place to look as it is just a small rotation at the joint at the end of the centre pipe to the rear box pipe that can make a huge difference in the proximity it sits to other parts. Also how far the pipe joint is pushed in together can then affect the proximity of the rear box to the rear bumper underskirt.


From the flexipipe all the way down to the rear box pipe there was plenty of space (and mine has a large additional intermediate box) so bearing in mind on some models with the same floorpan it has to accomodate an additional silencer box I would suggest this is why to you yours may appear to hang down low from the body in this area.

I have got lots of pictures of mine but not sure how these would help you identify, but if you can get some pictures of yours uploaded it may be obvious if wrong or locally made pipes.

Farrah

Hi,

Picture of mine but is a 1.4s but lots of room around centre pipe area even with intermediate box. That's why I say look closely at the rear end around where pipe of rear box sits near rear beam


Farrah

I haven't read all the replies for this but simple fix here!
If you haven't done 1,000's of miles since MOT/exhaust repair then take it back!, this problem occurs quite a lot when exhausts are 'repaired' as opposed to fitting a complete new system ( although it can happen on new systems, especially none OEM, which almost all exhaust replacements are!)
The exhaust system is quite simply ' a bit out of true' and when hot ( it expands) and when engine is used ( it moves on its engine mounts) some part is coming into contact with the car!
Like I said take it back because I would put money on the fact that it won't be the first time they have had one come back with the problem.
Paul m.

Chances are the replacement mid-section (including the flexi') is either not a perfect replica of the original so can touch the body when the car goes over a bump, or it's not correctly aligned with the silencer pipe, so that the rear silencer is touching something... or one or both of the exhaust hangers is old/loose and is allowing excessive movement. My money is on the latter.

New hangers are stiffer.. yours could be too aged and "loose". Also, the rubber mounts have a strap around the outside (or a sturdy cable tie, as above) to allow the mount to be "tightened" once the exhaust has been fitted through it. You could have just lost a strap.

Raputin, the Younger Mrs S' 1.2 Pop has a pipe that fits into the tunnel quite well.. as below... but that seems to have been achieved by putting a crease in the pipe which you can just about see in the photo of the sump. A new pipe I bought for it (waiting for that flexi to fail) is straighter and has no "crease" so it'll likely hang quite low compared to where it is now.. but as long as it's higher than the bottom of the front bumper, it's out of the way enough.

Ralf S.

Take it back to the place that carried out the repair and get them to sort it out properly.

Paying someone else to fix your car and then trying to sort out their mistakes yourself doesn't seem right somehow.

Of course, take it back to the garage, I missed the fact it’s only been a couple weeks since work had been done I quickly glanced over the op. Mind you a set of ramps is a well worth investment...