I’m the new owner of a 2019 ST3. The previous owner swapped the rear lights with a fiesta active which I think looks great.
I’m a bit concerned however about the road rumble/noise when on anything other than perfectly smooth tarmac. I appreciated the car would be refined but after driving 150 miles in a day I had tinnitus and a headache! An app on my phone measured the max dB at 110 and it sits between 80 and 90 when driving steadily.
It has 18inch wheels with Hancook Ventus S1 evo 3 tyres, the fronts at about 4mm and the rears newer.
I’m 41 and do have mild noise induced hearing loss from gigs when younger but have found I’m only comfortable in the car with earplugs which is faintly ridiculous - it’s not a caterham!
Has anyone any experience with different tyres / wheel sizes? Could the previous owner removed any sound deadening?!
It’s booked into a tyre garage tomorrow for a check but anything else to consider? If it doesn’t get better I’m worried I’ll have to buy a Golf.
That sounds like something might be wrong if it’s that loud! Have you checked the engine torque mounts? The rear one tends to fail sometimes, which can cause extra noise. Also, make sure your tire pressures are all within spec. Even slightly low pressure in the front tires can create more noise, especially with the 18" wheels that have less sidewall.
Personally, I’d say the app on your phone isn’t reliable. I’ve seen 103db on my Apple Watch when my MK7 was on a dyno at full WOT and high RPM, and I was a meter behind the car.
If the reading is accurate, something’s wrong, and I’d suggest the exhaust could be the cause. Do you drive with the valves open or closed?
I noticed the Scottish flag on the plate. It might be worth reaching out to Ross Laird at Laird Performance, as he’s a highly rated Fiesta tuning specialist up in Scotland and would likely have a good idea of what might be causing this issue on the MK8.
If not, you could also try posting a message on the ST owners page on Facebook.
There’s probably something wrong with the car if it’s that loud with what seems to be the stock exhaust. It could be a fairly serious exhaust leak, possibly from a broken flex pipe.
It sounds like it could be related to the engine mounts, as it shouldn’t be that loud inside. Even in Sport mode, you should still be able to have a normal conversation without raising your voice. When I had my old Mk7, I replaced the mounts with Powerflex ones, and even with the softest ones, the NVH (Noise, Vibration, Harshness) became borderline uncomfortable.
If possible, check with the previous owner to see if they replaced any mounts. The rear one is the most common to change, and you can find YouTube videos that show exactly where it is. It might be worth getting the car on a ramp to check it out easily.
Another possibility could be an issue with the symposer.
If there’s another one local, even at a dealer, a test drive might help confirm whether it’s an issue with your car or if it’s something common to all of them.
