Just bought a year-old Octy 2.0 manual TDI, a fortnight ago. It's the first diesel that I've owned, or driven in cold weather, but I've had smaller diesel holiday rental cars for years in Europe.

It was around freezing yesterday when I started up from cold, and soon got stuck in the Saturday town centre jams. I was alarmed at the level of vibration while at very low speed, or when stationary and in neutral. This was not just diesel clatter: it seemed like a clear imbalance shaking the car up and down.

The problem went away, once the engine was up to temperature. I haven't experienced it during the past 2 weeks of slightly warmer weather. Is this normal for a diesel, or must I go back to the dealers?

HI, I've never had this problem through 2 winters of PD140 ownership. Suggest a visit to dealer to see if there are any fault codes recorded - could be one of the many sensors not performing properly at very cold temps.

Thought so. I'll have to wait for a cold day or they won't believe me!

Could be the Dual Mass Flywheel (DMF)

If the car is a bit jerky at initial pick up then I would suspect this. It would be more noticeable at cold due to the increased vibrations from a cold engine and thicker fluids in the hydraulic damping component of the DMF.

I would guess the garage may thing this too at first even if it isn't the case as there have been a number of problems with there.

Other candidates are clogged/leaking EGR system, dodgy MAF, blocked air/fuel filter and injectors, plus probably many many more.

Let us know how you get on.