Hey everyone,

Just got back from a fantastic but bumpy driving trip around some smaller dirt roads in France in my Octavia Mk2 (2014 reg - yes, I know that's technically an Mk3, but the forum covers some late Mk2s.)

Towards the end of the trip, the car started making a really nasty crunching noise from the engine bay. It honestly sounded like something had got stuck or wrapped around the flywheel area. I managed to get it looked at by a local French garage who had a quick listen and suggested it was likely the flywheel needing replacement, but they said it was okay to drive home.

The weird thing is, after that initial diagnosis, the sound completely disappeared, and I drove the 400+ mile journey back to the UK without any issues whatsoever.

Obviously, the initial diagnosis of a potential DMF failure is still in the back of my mind, especially with those rough roads I was on. I'm planning to get it properly checked out here in Newcastle, but I'm curious to hear from anyone who's experienced similar issues.

My main questions are:

* What are the potential effects of continuing to drive with a failing DMF? Is a catastrophic failure likely, and what could that entail?

* How long can you typically drive with a faulty DMF before things go seriously wrong? I know it's a "how long is a piece of string" question, but any anecdotal experiences would be helpful.

* This car has had the DMF replaced once before, I believe within the last 5 years. Is it common for them to fail again relatively quickly, especially after some low-speed, bumpy driving?

Any insights or advice would be greatly appreciated! I'm keen to get this sorted but also trying to understand the urgency and potential risks involved.

Cheers!

The DMF usually starts rattling away before it fails completely and you can get a judder when taking off. If it does fail it can be catastrophic and wreck gearbox etc but if it was done 5 years ago unless the car has done huge mileage per year I doubt it would be going again. Mines on 120,000 with original clutch and no noises from Gbox etc. I may be wrong but I can't see bumpy roads affecting it at all unless it was badly fitted and has become loose but as the sound has gone again I doubt it. I would monitor it and get it checked out by a reputable garage and see how it goes. Get them to check that all the Gbox to engine bolts etc aare tight. Hopefully it was perhaps something wrapped round a drive shaft that has cleared itself.

Thanks so much for your reply and the insight.

You're right, the lack of rattling and juddering on takeoff is making me question the DMF diagnosis a bit more now, especially since the noise has completely disappeared. The thought of something just being temporarily stuck and then clearing itself is definitely a more hopeful scenario.

My car isn't doing massive mileage each year, probably around 8-10k at most, so a DMF failure after only 5 years (maybe less, I should check) did seem a bit premature.

I'm definitely planning on getting it checked out by a reputable garage. I'll make sure to specifically ask them to inspect the DMF and check all the gearbox to engine bolts and other fixings for tightness, plus maybe look for any signs of something having been wrapped around the driveshafts or other rotating parts.

Hopefully, it is something simple like you suggested. I'll keep an eye on it for any returning noises or vibrations in the meantime.

Thanks again for your advice, It's put my mind at a little bit more at ease. I'll update the thread once I've had it looked at by the garage.

I think its possible to check DMF throuh starter motor hole but as theres no vibration/noise its hopefully ok. Was the noise there all the time or only when you changed gear? If it happend when changing gear it could be a sticking release bearing? or perhaps a failing slave cylinder and what you were hearing was gears crunching slightly Hope its a one of or a simple fix.

Alasdair

Thanks for the additional thoughts and suggestions.

That's interesting about potentially checking the DMF through the starter motor hole – I'll definitely mention that to the garage when I take it in a couple of weeks.

Regarding the noise, it was definitely happening constantly while the car was running, not just when changing gears. That's why the initial thought went to something physically stuck or the flywheel itself. The fact that it stopped entirely is still a bit of a mystery.

A sticking release bearing or a failing slave cylinder causing a slight gear crunching noise is another possibility I hadn't considered, I'll make sure the mechanic checks those components as well.

Fingers crossed it is just a one-off or a simple fix! I appreciate your insights and I'll be sure to update the thread once the garage has had a look.