Towards the end of last year the engine started to sound a bit tractory at idle, evident inside and outside the car.  It sounded like something weighty bumping or rattling against something.  Of course I immediately went in my mind to worse case options - it's the DMF, it's an engine or transmission mount, it's a loose overhead manifold sprocket.  The noise did not alter with the clutch in or out though and disappeared as soon as the revs went above idle (so on a high idle, eg during DPF regen, it was fine).

 

One day I set about hunting down this noise.  I assumed I'd be elbows-deep in the engine bay, scalding myself on hot exhausts and turbochargers whilst grasping and poking stuff to see if it made a difference.  So prepared, I lifted the bonnet with the engine running and leant casually on the engine cover to begin removing it.  The noise stopped.  I let go and it returned.  So I whipped the engine cover off and was left with a rather unsightly but perfectly quiet idling engine.  Elated that it was nothing serious I refitted the cover and have done nothing more since.

 

However, it still bugs me.  The cover is quite a hefty thing and is clearly made from a number of components sandwiched together, although there is nothing apparently loose, separated or otherwise obviously broken.  All of the mounts to the engine are solid and secure and when in place it doesn't move.

 

So, this is a long-winded way of:

 

(1) offering a option to investigate if you have a rattly engine

(2) asking if anyone has heard similar?

(3) asking if anyone has fixed or disassembled the engine cover and knows what might be amiss inside?

 

Or should I source a replacement?  It looks like the part number is 03L103925AA and it is shared across various Skoda and other VAG models.  I am minded to fix it simply because there can't really be that much to it, and surely some silicone would sort it out for free (as I already have some).

I can always tell when I have failed to properly engage the four lugs when replacing the engine cover ~ by the rattle on idle.

Towards the end of last year the engine started to sound a bit tractory at idle, evident inside and outside the car.  It sounded like something weighty bumping or rattling against something.  Of course I immediately went in my mind to worse case options - it's the DMF, it's an engine or transmission mount, it's a loose overhead manifold sprocket.  The noise did not alter with the clutch in or out though and disappeared as soon as the revs went above idle (so on a high idle, eg during DPF regen, it was fine).

 

One day I set about hunting down this noise.  I assumed I'd be elbows-deep in the engine bay, scalding myself on hot exhausts and turbochargers whilst grasping and poking stuff to see if it made a difference.  So prepared, I lifted the bonnet with the engine running and leant casually on the engine cover to begin removing it.  The noise stopped.  I let go and it returned.  So I whipped the engine cover off and was left with a rather unsightly but perfectly quiet idling engine.  Elated that it was nothing serious I refitted the cover and have done nothing more since.

 

However, it still bugs me.  The cover is quite a hefty thing and is clearly made from a number of components sandwiched together, although there is nothing apparently loose, separated or otherwise obviously broken.  All of the mounts to the engine are solid and secure and when in place it doesn't move.

 

So, this is a long-winded way of:

 

(1) offering a option to investigate if you have a rattly engine

(2) asking if anyone has heard similar?

(3) asking if anyone has fixed or disassembled the engine cover and knows what might be amiss inside?

 

Or should I source a replacement?  It looks like the part number is 03L103925AA and it is shared across various Skoda and other VAG models.  I am minded to fix it simply because there can't really be that much to it, and surely some silicone would sort it out for free (as I already have some).

Does it mount onto the top of the engine using 4 small plastic spherical studs like the 1.8Tsi does?

If so, do all 4 sockets on the cover have a rubber insert in them? If not, then you may be hearing one of the mounting studs rattling against the plastic socket in the cover.

All lugs appear to be located properly and with their rubber sockets in place.  It sounds like something within the cover itself, as if some soundproofing material has delaminated or come adrift.