[Ares_]

Hi,
I noticed today that the engine makes a somehow loud noise when the turn signals or hazard lights or headlights are on. The noise comes from the exhaust side of the car and sounds like a prrrrr or something plastic to sync (I can't describe it better). Today it's a cold day in Athens (10oC max). Could this be considered normal? The noise is synchronized with the rate of the turn signals. Furthermore, when I switch on the headlights, the noise still there. I suspect that is somewhat connected with the alternator or with the exhaust, including the pre-cat. I tried to record it but it's masked with the engine noise.

 

[gdh300]

Could it be the alternator belt is slipping? It's usually a continuous squeal sound or a bit more rhythmical like a cicada. It will be worse when the belt is cold and/or damp. See if it gets worse by turning on every electrical device you can.

It might be the belt is on its way out, but might just be in need of tensioning.

 

[Turnup]

10C is not particularly cold. (might be for you but hereabouts right now it is just over zero). I think your alternator theory is plausible - is the battery in good condition?

 

[Ares_]

10C is not particularly cold. (might be for you but hereabouts right now it is just over zero). I think your alternator theory is plausible - is the battery in good condition?

The battery is less than a year old. No other symptoms except this noise as well as some slight more vibrations in the same frequency as the hazard lights (when the hazard lights are on).

 

[Turnup]

The battery is less than a year old. No other symptoms except this noise as well as some slight more vibrations in the same frequency as the hazard lights (when the hazard lights are on).

Means very little. Is it properly charged? Can you measure the resting voltage and again with the engine running?

Does this car have an overrun clutch alternator pulley?

Jave you tried listening to it with the bonnet up to see is you can localise the noise?

 

[Ares_]

I think it's not like a cicada. I did this trick by turning on every device and the noise got louder. Maybe it's the belt slipping or something related. Do we exclude the exhaust manifold leak?
I think the noise comes from behind the engine. I listened with the hood opened. The car seems to have an overrun clutch alternator pulley.

I can't measure the voltage by myself. In any case I arrange an appointment with the mechanic tomorrow. I will keep you updated.

Sent from my Redmi Note 9 Pro using Tapatalk

 

[Ares_]

UPDATE!
I just returned from the mechanic. The noise resembled a resonance due to bad or worn engine mounts (especially the right one). However, the mechanic identified that the noise was due to 3 reasons
Worn auxiliary belt
Worn auxiliary belt tensioner
Leaky exhaust flexible pipe (we call this in Greece exhaust spiral).

I replaced all of them. Also, the whole exhaust system is further stable now. The noise of the alternator area was disappeared, there is no play at the belt tensioner, and the engine noise reduced as well, both inside and outside of the car.

Even the ticking noise of the engine is reduced. However, the valves are still tapping! (permanent headache )

In the future, I plan to change the engine mounts to further reduce noise and vibrations. However, the mechanic insists on not trying this at this moment since it's a waste of money.