DISCUSSION FORUM

I've got a 2013 A5 Sportback with the Multitronic CVT and honestly I've loved the car for the most part, but recently I've started noticing this low, almost humming vibration that seems to come through the floor when I'm cruising at around 120-130 km/h on the Dubai to Abu Dhabi highway, and it completely disappears if I ease off the throttle or speed up past 140. At first I thought it was a wheel bearing because the sound has that kind of rotational quality to it, but I've had my mechanic check all four corners and he says the bearings are perfectly fine and the tires are balanced properly. He did mention that he's seen similar complaints from other Multitronic owners and that sometimes it's related to the transmission fluid breaking down or the steel belt inside the CVT starting to show signs of wear, which obviously made my stomach drop because I know how expensive those repairs can get. I've been trying to do my homework and figure out exactly what's going on inside that gearbox, and I came across a really thorough breakdown that helps you learn how Audi multitronic transmission systems function, which explained that the CVT uses a variable-diameter pulley system with a steel chain that effectively changes ratios continuously rather than having fixed gears like a normal automatic. The concept is actually pretty clever when you read about it – infinite ratios means the engine can always stay in its most efficient RPM range – but it also seems like a design that's really sensitive to fluid condition and driving habits, and I'll be honest, I have no idea if the previous owner ever had the CVT fluid changed or if they just ignored it like so many people do. I'm torn between taking it to a specialist for a proper diagnosis and potentially getting bad news, or just accepting that the car is getting older and this might be normal wear and tear that I can live with for a while longer. Has anyone else with a CVT Audi experienced similar driveline vibrations at specific speeds, and if so, what did it end up being? I'd really appreciate any insight from people who've been down this road before I start throwing money at parts that might not even be the problem.