Just now i went to petrol station to fill the tank up a bit of petrol overflow and came out, the petrol station attendant saw and came with his bucket of water thing to rinse of the petrol that overflow. But i saw when he was doing it a bit of water went to into the tank. This is bad right?? What should i do now? Car in use was a perodua bezza.

nope... still okay..... water is h20.... so it will help with the cleaning process

Water and oil does not mix. It’ll float on top of the tank. If a little, then you should be worried as it’ll vaporized eventually.

Did u close back the petrol cap before he rinse it?

How does the water vapourise in an enclosed fuel tank?
Actually water does mix with fuel, unless you don't drive the car. Then water will settle at the *bottom* of the tank, not float.

He suspected water got into his tank, so this means the cap was not closed?

I also not sure.
But if we screw the cap to close and pour water over the cap, it should be fine right? Because i notice the water will flow into a hole and out of the car.

so i just leave it?
But according to what i google it will cause quite a serious damage to few parts?

No it was open. I went to put back the petrol pump and when i turn around i saw the attendant was pouring water there and i did see some water enter the hole...

So what you suggest i do. I do use the car daily but only about 15-20 km daily. Yesterday after i pump i came back home which was less then 5km away. Water must have settle at the bottom by now?

do nothing, monitor the car for any signs of trouble... if a bit shouldn't matter.

Some water getting sprayed by the injectors into the combustion chamber will not cause any issue. If the car is hesitating, feel underpowered, jerking during acceleration then maybe a lot of water get in.

Drive until almost empty a few times to make sure the water gets out.

Other way round, petrol floats on water.

Most of the water probably pumped out of the tank and through your engine by now.

Dude.. Just bring to a mechanic nearby and drain the fuel tank lah why so susah. Easy job. After that go refuel.

The small amount of water as described probably gets emulsified in the petrol fuel .......and consumed/burnt in normal way.

Modern car fueling system has a cap at the mouth to prevent water from seeping in. The damage won't be that high. These are all failsafe to prevent dummies doing stupid shit like pouring water at the fuel mouth area.

Ppl keep telling me water won't mix with petrol/diesel.

I guess they hey haven't seen cloudy petrol/diesel.

This +1,

Use a syphoon to get fluid out of the tank. Do it soon. If you can't, get a mechanic nearby to do it and bring a fuel can so you can drive your car to the fuel station.

After 2 or 3 cycle of fuel the water will drain or clean by the fuel additive that comes with the fuel.

A bit of water can’t do much harm to the car.

Isn't water is denser than petrol? Water will sink to the bottom of the tank.

Can try this type of fuel additive for condensation.

https://m.youtube.com/watch?v=Z140XgsoPcI

water in the tank is fine, just keep filling the tank with petrol to reduce any harmful effects. if a bit of water got into the tank theres nothing to worry about as all that matters is that the octane and knock index of the new mixed fluids are combustible with a spark plug and within engine operating specs. Water is actually a byproduct of combustion so its like having a bit of exhaust back into the engine which is what some car systems do to get rid of toxic gases and retard engine power when needed.

You'd be surprised on what you can make your engine run on, and can be modified with little effort to combust hydrogen gas. Maintenance is the most important thing.

hydrogen and water are two different component. ever heard of hyrolock?

if its just a splash its no harm. if its quite a large volume, then consider flushing.