Recently acquired a mk5 1.4 petrol manual, changed oil and filters and fixed a few electrical niggles, but when driven a bit hard on a quick blast, I’m getting the orange “cog” light on for the rest of the journey. Goes off when you stop the car and doesn’t necessarily come back on unless it gets a bit more hard acceleration/higher revs action.

Engine management light not on, and no faults logged on OBD. 
I was thinking initially check gearbox oil level? I’m not really clear on what kind of fault this light is likely to represent as opposed to the normal engine management light.

Any advice appreciated!

Used to get the same fault with a Connect Van I once had. Never anything stored in fault log. One day I managed to get to a dealer whilst the fault was still on and they read the DTC which was showing a fault with injector 3 or 4. As soon as the ignition was switch off the fault code would clear. In the end we got injector 3 replaced and all was well, never had the problem again.

The only thing you can do is try and get the DTC read while the fault is still on and see if there is a code.

Thanks - so on yours it was the cog light and not the "normal" engine management light? not really sure why its got both tbh, seeing as its a manaul.

I'll see if I can plug in and read it while its on.

Yes the odd thing was the Cog, the engine light never came on. Thats why it took us nearly a year to get to the cause of the problem.