Rumbling when shifting from D to L

Hi,

I bought a used car, which is all good. I tried to switch gear from D to L (L is the only low gear it has) before climbing a fairly steep road, but the car made kind of rumbling noise, which didn’t sound nice or normal I think.

Another time it didn’t do this noise.

Can you tell me why this happened? Perhaps I switched to the lower gear in the wrong time?

To switch to lower gear I keep the same speed (don’t slow down or anything) and just switch gear. If the car has already enough speed to climb a hill I don’t switch gear.

Thanks

Please tell us the MAKE and MODEL of the car, the year it was built and the current miles or kilometers on it. Then we may be able to narrow down some of the causes of your problem.

How fast were you going when you shifted into low gear ?

Suzuki Swift 2015, 27,000 km.

How fast were you going when you shifted into low gear ?

Maybe 30-40 kph. After reading a bit online, perhaps I was going a bit too fast actually, I’m guessing, but not so sure. The rumbling noise is probably better described as the engine revving up more than needed.