Start Stop on TFSI

[Haz123]

Hey,

So I am finally getting to grips with my new Audi A3, it's only a 1.2 but I have been quite impressed with the punch it has and for an entry-level engine I think it is great.

Just wanted to ask if anyone else has experienced a light humming sound once the engine is re-engaged after being turned off by the start/stop function? It quickly goes but I can hear it when the radio/air con is off.

What will happen is I will approach a set of traffic lights, the engine will cut out and then when I re-engage the engine I can hear a light humming sound sometimes (not always....!).

The car has just been serviced and had a health check and nothing came up but I have noticed this beforehand, and it hasn't gone away. Is it normal? It only happens with the stop-start and can't hear it at any other point so I am hoping it's nothing to worry about and is something that is normal..

Any help would be great!
Cheers
Haz

 

[Haz123]

Any thoughts at all anyone?

 

[Darren92]

Any thoughts at all anyone?

You only posted 2 hours ago plus its a Sunday so the forum isn't always as active as mid-week, give people a chance.

FWIW, I'd say its normal. Don't worry about minor things, they'll just drive you mad and you'll start to hate the car if you pick up on every noise.

 

[Chris43]

Modern engines have electric motor driven oil and coolant pumps rather than belt driven off the crankshaft so its likely to be this you can hear. Stop start technology requires the engine cooling / lubrication to be independent of crank RPM to reduce engine wear and thermal damage.

I bet you get similar sounds when you initally kill the engine at the end of your journey. (My TDI makes all manner of noises)

In the end it's nothing to worry about.

 

[Haz123]

You only posted 2 hours ago plus its a Sunday so the forum isn't always as active as mid-week, give people a chance.

FWIW, I'd say its normal. Don't worry about minor things, they'll just drive you mad and you'll start to hate the car if you pick up on every noise.

You're right... sorry!

True, I think that if cars were totally noise free it probably wouldn't be a good sign....

 

[Haz123]

Modern engines have electric motor driven oil and coolant pumps rather than belt driven off the crankshaft so its likely to be this you can hear. Stop start technology requires the engine cooling / lubrication to be independent of crank RPM to prevent engine wear and thermal damage.

I bet you get similar sounds when you initally kill the engine at the end of your journey. (My TDI makes all manor of noises)

In the end it's nothing to worry about.

Would make sense, I didn't consider that the oil and cooling would be interdependent.... but I guess it prevents major wear and tear.

Thanks for your input

 

[Matchman54]

Do you have the electronic handbrake on your vehicle?.The humming noise could be the handbrake disengaging when you put the car under load when pulling off. Also you can hear it when you apply the handbrake ie when you press the button.