Intermittent engine knocking

I’ll be upfront, this is not a 5 related question, but as you are friendly helpful bunch, you may not mind.

My daily driver is a mk5 golf, 1.9 diesel with 265k miles on the clock. Original gearbox and clutch. Still drives well, has plenty of torque, and is much faster than my 5.

It has developed an intermittent engine knock, but it’s quite strange. Only occurs when the engine is hot - not just up to temp hot, but hot after a decent drive. Only occurs when idling, but only when knocked out of gear and the clutch pedal released. If I sit idling when the pedal down, no knocking. Pretty much as soon as a lift it, knocking starts. Goes away if I go into gear and move the car. Doesn’t go away just by rev’ing.

Wondering if it’s the clutch rather than the engine. I do have a little bit of judder when the car is cold and has been sat for a few days. This goes away pretty quickly once everything is warmed up.

At 265k miles on the clock, I’m not going to spend a lot of money on this, and happy to drive it into the ground. Just really want to know if I have a time bomb on my hands so I can prepare for imminent failure.

Many thanks.

Clutch release bearing?

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If it was the engine it would be constant so most likely it’s got a dual mass flywheel getting ready to expire.

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Looks like that’s the culprit. After your suggestion, found a YouTube video of a T5 with a failed flywheel. Same noise.

Dual mass flywheel on its way out is my guess…
Can be expensive but id guess you could replace with a solid flywheel at reduced cost.
Had same issue and solid flywheel fitted on a previous car of mine… vw Bora pd engine

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Dual mass flywheel on its way out.
Be wary of replacing it with a (much cheaper) solid flywheel, as the harmonic vibrations (that are damped out by the DMF) can/will take the gearbox out.

I’d say dual mass fly wheel as well.
My MK4 TDI Golf destroyed its gearbox at 140k miles.
The culprit was the DMF. I did notice slight clunking noises when idling but the garage and main stealer sent me away after reassuring me all was well.
Common problem on golfs from 2005 onwards.
To be fair yours has lasted pretty well though👍

No an expert on DM by any means but I don’t think it’s an issue that can be nursed for a long period of time. You have obviously nursed this car really well, hence the mileage on original parts but something had to give.
Don’t know how much it would cost to fit but good parts cheaper than I expected.
As advised, particularly at this money, stick to DM.
Last DMs I had knowledge of were on a Volvo and an old Rav4. Both cost well over a grand to fully repair.

Thanks all. After discussion with my trusted garage I’m going to get the flywheel and clutch replaced to give some life to the old girl. Hopefully used car prices come down a bit next year, and then it may be time to say goodbye at last. We’ve had the car since new and it’s been a great workhorse. At 17 years old and 265k miles it’s to be expected that parts are going to fail.

This thread can be closed now (I’ll do that if I can work out how).

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