Punto Mk1 turbo engine drone
Discussion
I wonder if fellow italian car phe'r fans mite be able to offer any advice here.....my engine runs fine but on a run im getting a drone noise come in every gear more noticeable in 4th and 5th as these are the cruising gears at around 2500rpm which equates to my sort of steady cruising speed of about 65-70 so its very annoying on a long journey. drive below that and you get cars backed up behind you or you feel compelled to move up to 80+ where the revs are over 3000rpm and the noise goes. none of this droning noise is noticeable on boost.
Also , on lift off at motorway speeds there is a distinct barrrp noise from engine or exhaust which matches the reducing speed - its very hard to tell but its typically an exhaust sounding noise to me. new rear section in 2013. new front downpipe 2 weeks ago. cat is fine. hangers all look good and the rubbers. not checked the heatshields for contact yet.
I know the centre silencer took a knock a few years ago and a small hole was found and welded up.......could it be this silencer thats life expired inside maybe? its got to be quite old but isnt showing signs of obvious leaks.
front tyres are castellated so these will be replaced this year to rule out sawtooth drone (if thats what i am getting) but this wouldnt give that barrpp noise on lift off (or is it called overrun-can never remember?) anyway.
Also , on lift off at motorway speeds there is a distinct barrrp noise from engine or exhaust which matches the reducing speed - its very hard to tell but its typically an exhaust sounding noise to me. new rear section in 2013. new front downpipe 2 weeks ago. cat is fine. hangers all look good and the rubbers. not checked the heatshields for contact yet.
I know the centre silencer took a knock a few years ago and a small hole was found and welded up.......could it be this silencer thats life expired inside maybe? its got to be quite old but isnt showing signs of obvious leaks.
front tyres are castellated so these will be replaced this year to rule out sawtooth drone (if thats what i am getting) but this wouldnt give that barrpp noise on lift off (or is it called overrun-can never remember?) anyway.
As I was reading, I was thinking "tyres" - seems like you've already twigged the cause of the drone
For the lift-off sound, I'd check your inlet tract, including your air filter. Once you're off the throttle, there's little or no exhaust gasses going through the exhaust (I assume its a single-point injection engine?). Therefore the noise is more likely to be intake noise, which will change when the throttle is closed
A cone filter will often give all sorts of unusual and unwanted noise.
Doe the Mk1 Punto Turbo have a dump valve - if so, it might be worth checking to see its still sealing properly
For the lift-off sound, I'd check your inlet tract, including your air filter. Once you're off the throttle, there's little or no exhaust gasses going through the exhaust (I assume its a single-point injection engine?). Therefore the noise is more likely to be intake noise, which will change when the throttle is closed
A cone filter will often give all sorts of unusual and unwanted noise.
Doe the Mk1 Punto Turbo have a dump valve - if so, it might be worth checking to see its still sealing properly
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