[Vladimir]

I got a new garage this year which has some openings, so temperature in it is almost the same as outside. As winter came, I noticed this knocking sound when I start the car when it is cold. The sound is clearly audible inside the car but I almost cannot distinguish it outside with the hood open. If I rev the engine a bit (like +200-300 rpm) it disappears. It also completely disappears after only 30-60 seconds, i.e. the car is a bit warm but far from normal operating temperature.

Following this thread I checked the power steering fluid level and it was slightly low, so I filled it in. There was no change, the sound remains.

I tried to capture the sound, including how it disappears when revving the engine in the following video.

UPDATE: The sound is clearly audible from the outside, front left underneath the car as seen on this video:

Any ideas of what this might be and how to handle it?

 

[Bummer]

To me it sounds more like a bad bearing rather than something in the engine knocking. Maybe one of the belt rollers? Waterpump? Throwout bearing? Does pressing a clutch affect it? Maybe try starting it without belts, see if sound remains

 

[Sailor24]

I noticed this knocking sound when I start the car when it is cold.

That is a rattle from something outside the engine. If you count the clicks in so many seconds, in other words how fast it happens. At idle your car makes ~ 10 revs per second, that click is about every 1/2 second. There are so many things that get loose in time it is hard to say. Oil filter mounts and the same for PS reservoir, plus a thousand other things. All I can say is that does not sound serious.

 

[Qurefest]

I got a new garage this year which has some openings, so temperature in it is almost the same as outside. As winter came, I noticed this knocking sound when I start the car when it is cold. The sound is clearly audible inside the car but I almost cannot distinguish it outside with the hood open. If I rev the engine a bit (like +200-300 rpm) it disappears. It also completely disappears after only 30-60 seconds, i.e. the car is a bit warm but far from normal operating temperature.

Following this thread I checked the power steering fluid level and it was slightly low, so I filled it in. There was no change, the sound remains.

I tried to capture the sound, including how it disappears when revving the engine in the following

I got a new garage this year which has some openings, so temperature in it is almost the same as outside. As winter came, I noticed this knocking sound when I start the car when it is cold. The sound is clearly audible inside the car but I almost cannot distinguish it outside with the hood open. If I rev the engine a bit (like +200-300 rpm) it disappears. It also completely disappears after only 30-60 seconds, i.e. the car is a bit warm but far from normal operating temperature.

Following this thread I checked the power steering fluid level and it was slightly low, so I filled it in. There was no change, the sound remains.

I tried to capture the sound, including how it disappears when revving the engine in the following video.

Any ideas of what this might be and how to handle it?

My opinion…..
Sounds like a bad Vanos to me!
It could be alot more to it

 

[Vladimir]

My opinion…..
Sounds like a bad Vanos to me!
It could be alot more to it

What would be the way to check if it's the Vanos?

 

[Celicasaur]

Sounds like a bad pulley/tensioner. It's nothing sinister.