Hi!

I own a three month old TwinAir Lounge (85) and it's a fun little car for sure, but I have a couple of questions about the sound it makes in certain conditions. I'm more curious than worried about both of these things, because all engines make unique side noises.

Firstly, I get a high pitched whine after a cold start (under +5C). Sometimes I get it for a second right after it starts, but usually I have to rev the engine a bit. It reminds me of the sound all reverse gears make, but it has an even higher pitch to it and it occures with the clutch down as well. Could this be the utility belt loose or something? It does go away after 500 meters or so and the retailer is aware of it if you will. Does anybody else get this?

Another weird thing about this engine is a very distinctive rattling or knocking sound happening at idle and under light revving whenever the engine isn't fully warm (temp at middle) - or basically when it idles at over 900 rpm. Half warm it goes away with the slightest press of the gas pedal. It reminds me of a diesel which some say the TA sounds like anyway. You can hear this sound on a few YouTube videos that have the bonnet open (I'm not allowed to post links yet, but google "FIAT 500 TwinAir engine (875cc, two-cilinder)")

Other than this, it's an absolute laugh to launch from motorway ramps and big medium speed crosses. It gives a genuine petrol engine sound and nothing like a diesel, thank god. I had to drive two different newish loaners last month, because of an early rear bumper accident (second day, ugh), Corsa and Micra. Both sounded awful and abstract. Well I guess the Italians have always been better at this stuff...

oetseli said:

Hi!

I own a three month old TwinAir Lounge (85) and it's a fun little car for sure, but I have a couple of questions about the sound it makes in certain conditions. I'm more curious than worried about both of these things, because all engines make unique side noises.

Firstly, I get a high pitched whine after a cold start (under +5C). Sometimes I get it for a second right after it starts, but usually I have to rev the engine a bit. It reminds me of the sound all reverse gears make, but it has an even higher pitch to it and it occures with the clutch down as well. Could this be the utility belt loose or something? It does go away after 500 meters or so and the retailer is aware of it if you will. Does anybody else get this?

Click to expand...

Yep. I get that occasionally, I suspect it's the turbo; It sounds as though the EMS restricts boost when the engine is *very* cold by operating the recirc dump valve.

oetseli said:

Another weird thing about this engine is a very distinctive rattling or knocking sound happening at idle and under light revving whenever the engine isn't fully warm (temp at middle) - or basically when it idles at over 900 rpm. Half warm it goes away with the slightest press of the gas pedal. It reminds me of a diesel which some say the TA sounds like anyway. You can hear this sound on a few YouTube videos that have the bonnet open (I'm not allowed to post links yet, but google "FIAT 500 TwinAir engine (875cc, two-cilinder)")

Click to expand...

Yes, that's normal. Partly the wastegate linkage chattering, and partly the valvegear, when the engine is low speed the multi air system is operating in multi lift mode, which means the inlet valves are lifted and closed twice during an induction stroke - I suspect what we're hearing is a bit of hydraulic 'knock' through the multi air unit, as you say the noise goes away when the oil gets hotter (and thinner). Nothing to worry about, my engine has done it since day zero, and it's done nearly 10,000 miles. Does it less when the ambient temperature is higher.

oetseli said:

Other than this, it's an absolute laugh to launch from motorway ramps and big medium speed crosses. It gives a genuine petrol engine sound and nothing like a diesel, thank god. I had to drive two different newish loaners last month, because of an early rear bumper accident (second day, ugh), Corsa and Micra. Both sounded awful and abstract. Well I guess the Italians have always been better at this stuff...

Click to expand...

It's a little cracker and great fun to drive.

I had the same knocking sound at start up for a few days after the service, its all back to normal now, sorry not sure what may have caused it. Some people here will be able to help.

edit : you have the answers !!

I didn't suspect the turbo, but it does make sense. Using the same logic, it should't feel as torquey cold either due to limited boost?

I did think multilift was part of the rattling sound since the valves are effectively operating at double rate, but with the same low idle oil pressure. A lot of stuff happening in this little mouse of an engine.

The best choice of words I've seen concerning the idle sound is "it sounds like a bag of nails at tickover". I'd say that's quite correct .

Likewise it sounds very comfortable after a long drive when it absolutely has had enough time to get steamy under the bonnet. This car would go well with a Ducati. Hmm...

Thanks!