I was topping up the washer fluid on my car today and noticed I could hear a slight hissing at idle. I had a quick look over the engine and noticed that this hose running from the intake manifold had a split in it. As a temporary measure I've wrapped it with insulating tape which seems to have sealed it and got rid of the hissing - but wondered if anyone know what this hose was or what it did??
thanks for any help/advice!