Technical Fiat 500 1.2 silencer/muffler hook knock the chassis - HELP

[szamat2012a]

Hello!

I recently replaced the complete exhaust system (OEM - catalytic converter, centre pipe, exhaust silencer) in my small 2009 Fiat 500 1.2 8v car, which I bought from a car that was dismantled (a few 100 km). The disassembled system is from a 2018 Fiat 500 1.2, but I understand the exhaust system should still be good.

The catalytic converter pipe and the middle pipe were difficult to join but that's not my problem, it's that the right hook of the exhaust drum is very close to the body and sometimes I hear a knocking sound from the rear.

The rubber hangers are new, but I can still hear it, and even if I warm it up by hand I can still hear it.

What could be the problem, am I not hitting the tubes right?

Thanks for your help!

 

[bugsymike]

Hello!

I recently replaced the complete exhaust system (OEM - catalytic converter, centre pipe, exhaust silencer) in my small 2009 Fiat 500 1.2 8v car, which I bought from a car that was dismantled (a few 100 km). The disassembled system is from a 2018 Fiat 500 1.2, but I understand the exhaust system should still be good.

The catalytic converter pipe and the middle pipe were difficult to join but that's not my problem, it's that the right hook of the exhaust drum is very close to the body and sometimes I hear a knocking sound from the rear.

The rubber hangers are new, but I can still hear it, and even if I warm it up by hand I can still hear it.

What could be the problem, am I not hitting the tubes right?

View attachment 457478
Thanks for your help!

I have often found "pattern" or non genuine OEM exhaust parts are a poor fit and need a little bend on brackets and mounting points etc.
Fir instance the part you are indicating may just need a crow bar or strong screwdriver to bend the rod to a better position to give clearance.
Also if second hand , there is nothing to say previous owner didn't back into an obstruction bending the exhaust.

 

[szamat2012a]

I have often found "pattern" or non genuine OEM exhaust parts are a poor fit and need a little bend on brackets and mounting points etc.
Fir instance the part you are indicating may just need a crow bar or strong screwdriver to bend the rod to a better position to give clearance.
Also if second hand , there is nothing to say previous owner didn't back into an obstruction bending the exhaust.

Thank you very much for your reply!
Isn't it possible that you have to butt the pipe fittings together so that the front of the exhaust drum hook is in line with the front of the suspension hooks?

 

[bugsymike]

Thank you very much for your reply!
Isn't it possible that you have to butt the pipe fittings together so that the front of the exhaust drum hook is in line with the front of the suspension hooks?

Off hand I don't know, it depends how the exhaust was made and how it all lines up, often trial and error to get the best position before tightening everything up finally.
After over 50 years in the motor trade I have had to deal with all sorts of parts. Even brackets welded on inm the wrong position!
Would say though much easier on a ramp.

 

[szamat2012a]

Off hand I don't know, it depends how the exhaust was made and how it all lines up, often trial and error to get the best position before tightening everything up finally.
After over 50 years in the motor trade I have had to deal with all sorts of parts. Even brackets welded on inm the wrong position!
Would say though much easier on a ramp.

Of course, we’re repairing the exhaust system from a pit. I just quickly took this picture to show the issue I’m having. Do you have any tips on how to fit the middle exhaust pipe to the catalytic converter pipe? When we first assembled it, it was very difficult to fit them together.

 

[bugsymike]

Of course, we’re repairing the exhaust system from a pit. I just quickly took this picture to show the issue I’m having. Do you have any tips on how to fit the middle exhaust pipe to the catalytic converter pipe? When we first assembled it, it was very difficult to fit them together.

Without being there looking at it , it is difficult to see the problem.
Can you compare the old system with the new one?

 

[szamat2012a]

Without being there looking at it , it is difficult to see the problem.
Can you compare the old system with the new one?

I'll tell you the gist of the story. My girlfriend and I bought the mentioned 500 used at the beginning of summer, and I started maintaining it. I noticed that it had the wrong catalytic converter and exhaust system. (It had a Euro 4 catalytic converter from a Fiat Panda 1.2/1.1, which was restricting the engine).
I have a degree in automotive engineering, but I like to seek advice from more experienced people when it comes to repairs.
A friend of mine managed to get a Euro 6 catalytic converter and a complete exhaust system.
We installed it a month ago.

 

[bugsymike]

I'll tell you the gist of the story. My girlfriend and I bought the mentioned 500 used at the beginning of summer, and I started maintaining it. I noticed that it had the wrong catalytic converter and exhaust system. (It had a Euro 4 catalytic converter from a Fiat Panda 1.2/1.1, which was restricting the engine).
I have a degree in automotive engineering, but I like to seek advice from more experienced people when it comes to repairs.
A friend of mine managed to get a Euro 6 catalytic converter and a complete exhaust system.
We installed it a month ago.

It sounds like you know the specification for your model better that me, around here 2009 vehicles were still on Euro 5 I think.

The main difference between Euro 5 and Euro 6 is that: Euro 5 engines focused largely on carbon dioxide emissions (CO2), while Euro 6 is primarily focused on reducing nitrogen oxide emissions (NOx).

Does this mean that your possibly trying to get higher spec emission standards by trying to run the Euro 5 cat system than your ECU is configured for?
My knowledge is mainly on older vehicles as I have retired after over 50 years in Motor trade.

 

[szamat2012a]

It sounds like you know the specification for your model better that me, around here 2009 vehicles were still on Euro 5 I think.

The main difference between Euro 5 and Euro 6 is that: Euro 5 engines focused largely on carbon dioxide emissions (CO2), while Euro 6 is primarily focused on reducing nitrogen oxide emissions (NOx).

Does this mean that your possibly trying to get higher spec emission standards by trying to run the Euro 5 cat system than your ECU is configured for?
My knowledge is mainly on older vehicles as I have retired after over 50 years in Motor trade.

Yes, you're seeing it right. However, the goal with the Euro 6 system wasn’t to improve emissions, but simply to replace the wrong system since I got the Euro 6 system at a great price. Since the body (chassis) of the car hasn’t fundamentally changed, I decided to install the used exhaust system.
The ECU wasn’t reprogrammed because it would have been unnecessary – based on exhaust gas simulations, it was basically just an instant system swap for me. Of course, emissions and engine specifications were measured and examined with this system. (We achieved better fuel consumption and performance, but that wasn’t the goal – it was purely about replacing the exhaust system).
The only thing that bothers me is that the exhaust hanger knocks against the body.

 

[bugsymike]

Yes, you're seeing it right. However, the goal with the Euro 6 system wasn’t to improve emissions, but simply to replace the wrong system since I got the Euro 6 system at a great price. Since the body (chassis) of the car hasn’t fundamentally changed, I decided to install the used exhaust system.
The ECU wasn’t reprogrammed because it would have been unnecessary – based on exhaust gas simulations, it was basically just an instant system swap for me. Of course, emissions and engine specifications were measured and examined with this system. (We achieved better fuel consumption and performance, but that wasn’t the goal – it was purely about replacing the exhaust system).
The only thing that bothers me is that the exhaust hanger knocks against the body.

I didn't know if the chemical reaction in a Euro 5 cat was different for a Euro 6 cat if trying to reduce different emissions?
Re the exhaust knocking, I would probably slacken off any clamps at joins and position exhaust by twisting slightly to give the best position, but even then a little "gentle persuasion" on the mounting bracket is often the answer.
Re the bracket and rubber mount in your photo , could you bend the bracket mount on the box down a little to give clearance and then compensate by fitting a longer rubber mount to give a better clearance overall?