Stupid question - engine noise

[Lam999]

I’m sure this is a stupid question, sorry in advance

I’ve traded my 1.2 65 plate leon for a 1.4 18 plate

When I’m driving at 70 mph, then engine seems to hum and then stop, then start again, in a cycle, I don’t know how to describe it. 3 seconds on then 3 off? It’s only while going a constant speed that I notice it?

Is this just the noise I’m not used to from the bigger engine or something I should be concerned about, it’s at 11k miles so it’s due a service soon anyway

 

[Legojon]

Does it have some kind of eco environment saving thing that cuts a cylinder?

 

[Lam999]

Does it have some kind of eco environment saving thing that cuts a cylinder?

It was in eco mode, yeah it’s got the two cyclinder act system, but it was making the noise even when it wasn’t in two cyclinder mode, I’ll try it in normal drive mode and see if that changes it?