Today the knocking sound reoccurred.

But now it was DRY...no rain.

I had it this morning and also this afternoon coming back from work on the motorway +/- 120km/h.
The knocking noise started in both cases after about 10min drive.

Ok thx, I'm sure they did the Gurgling modification.

I hope to get this sorted to, on mine !

Hi, did they mention witch drains they modified?

There are many Facebook threads relating to this. From memory a drainage tube is the problem- I think it’s a simple fix. Could not find anything (yet) on Facebook. Only on YouTube a drainage unclogging. Nothing related to the knocking noise. Would you have links? The link does not seem to work on t...

In my case I think more front the right side. But the trip was to short.

squint wrote: ↑Sat Jun 20, 2020 1:50 pm There are many Facebook threads relating to this.
From memory a drainage tube is the problem- I think it’s a simple fix.

Could not find anything (yet) on Facebook. Only on YouTube a drainage unclogging. Nothing related to the knocking noise.
Would you have links?

After months now with the first rain in got the knocking sound back. Sadly I could not test where the sounds is coming from. I hope there will be a solution....

Where was the drain hole please?
Photo from it maybe?

I am using the PoorBoys for many years now, for me still the best protection.

I will check the wipers and the sunroof as soon as I get back on the motorway ...and in heavy rain.
To bad it is a few days dry now.

Will report as soon as I get more information.

Thx for the help and suggestions.