This is my first post on this forum, so let me convey my greetings to all other distinguished members

Now, I'd like to ask you for the help, if it's possible...Just bought a new Skoda Octavia 1.4 TSI (122HP). I have done some 400 miles on it so far, and there's one thing that annoys me terribly. It's this strange knocking sound...more like dumped rattle that appears whenever I release the clutch - somewhere at the biting point - and then until it's full released....It happens only when I start from zero speed - in first, in reverse and if I try to start in second....It is more audible if I start uphill (or apply handbrake). If I apply throttle in idle - nothing happens, so as when I change gears while already driving. I believe that its a bit louder if the engine is cold. Need to add that it happens only at low RPM's - and if I give it more throttle (like a beginner driver - if you know what I mean) - it could start rattle - free.

So I went to dealer's garage and reported malfunction. They initially said that that's normal sound of transmission, but I left the car anyway. Same day I returned for the car, and they have told me that they have diagnosed the origin of the rattle and it's due to the resonance of the turbo in the exhaust system. I challenged their theory with the fact that rattle also shows as a vibration that transfers through the clutch, but they insisted that it is normal. I took the car and now I'm trying to ignore the rattle which doesn't seem possible.

Could anyone confirm that this rattle could be indeed turbine resonating through the exhaust.

Much thankful!

From what you've said -- It rattles more when there's more torque applied (uphill / handbrake) - to me that means less chance of it being clutch release bearing or fork related. So i'm thinking something in the drive train.

It happens in R, 1 & 2 moving away from standstill so that makes me think it's less likely to be gearbox related although i guess its still possible it could be main bearing or something like that. These are the gears (especially from standing) where the clutch is working hardest. Also when you apply throttle in neutral there's no noise. So from these 2 facts i'd derive that It's only detectable when the clutch / DMF is working hard.

From what you've said i'm thinking its in the area of Dual Mass Flywheel or clutch plate.

If it's either of these components it will get worse and new symptoms will appear -- should be easier to diagnose then. I know that's not much use to you just now but i just don't know, i can't really think of any tests to try to prove / disprove.

If you are rolling along slowly, say 20km/h, and you choose 6th gear and start to let the clutch out -- does it happen here? Might be hard to hear because engine will really struggle.

Can you test drive another car, same model, from a dealer anywhere nearby? See if it behaves the same?

Thanks for your reply....

Friend of mine just bought exactly the same model.....It will arrive in a month or so. So I said to these guys in the garage (we're talking about major garage of VW/Skoda in Brussels): hey, I can live with your explanation for time being (resonance of a turbo!?), but when a friend of mine gets his 1.4 TSI, and if there's no resonance - I'LL BE BACK! I mean, they were explaining me how turbo works like I was an infant. I was driving Renault GT turbo before some of them started to walk, but I have never felt any such resonance...Perhaps they've heard of wastegate flutter or blow-of valve chatter or whatever, so they think if there's any sound there - it's because of turbo!

I'll try that thing with 6th gear on low speed and report back what happens...

Other than that, I'm very very satisfied with this car....build quality, how it handles driving, how its spacious and comfortable, the consumption, the power of this magnificent engine, the price - everything is great! Just a couple of plastic parts in the cockpit could have been better, but I'm not gonna complain.

Hi,

What did you found out on that subject? I have the same noise on my brand new 1.2 TSI (105hp).

Greets!