At the end of my road there is a steepish incline before a main road. My usual is to drive down allowing the car to take me at its own pace in gear. With these cold mornings I have heard quite a weird rattle, but only then. I can't replicate it again as the engine heats up and it's fine. Also as soon as you apply a little throttle it's gone!

Anyone else had this issue please? And it's not the usual diesel sound.

Car is a 2007 pd105 octavia estate

Edited 26 March, 201313 yr by zeffania

Engine mounts + dogbone mount worn out by now? Or have you blanked out the EGR recently?

If the former, use lower gear and/or replace the mounts, first make sure all bolts are there if the car has had belt job in the past (partly stripping threads on alloy engine console is unfortunately common, though not too difficult to replace the console afterwards).

Edited 26 March, 201313 yr by dieselV6

Is car due a service in about 2_000 miles? if so, it's probably thick oil making the hydraulic tappets slightly sticky.

dieselV6's suggestions are also possible, as is a bit of noise from a DMF (presumes car is a manual).

...Or have you blanked out the EGR recently?...

+1

EGR is off from startup - that's why you have to blip the throttle during EGR testing.

As I read it, OP is just releasing the brake and rolling away without any throttle.

+1

EGR is off from startup - that's why you have to blip the throttle during EGR testing.

As I read it, OP is just releasing the brake and rolling away without any throttle.

That's correct, usually go down the hill in second.

Car is not due a service, was only done in January.

EGR? Will have a search and see what that is, thanks guys. edit, some people have mentioned a drop in fuel economy, but mine seems the same as it has always been, 51mpg

Edited 26 March, 201313 yr by zeffania

It is not an actual problem, it is just that Exhaust Gas Recirculation is not activated until you touch accelerator, and the engine has much sharper (tractorier? ) sound, as peak pressure in cylinders is higher.

Actually, at least on older 1.9/2.5 EGR would activate on startup but then go off after around 30sec, similarly glow plugs would do the same.

You can see if this is what you hear by touching accelerator just prior to moving (then drive same way as before when you got the sound), see if you get no "tractor" sound anymore.