Hi all!

New here but I can't seem to find any answers to my problem on Google.

After noticing my acceleration was sluggish, I decided to check if the air filter needed replacing. Filter's fine but I noticed that a hose going into the box (which I'm still not sure its purpose) was leaking and the sponge surrounding it disintegrated when I removed it. The liquid was shiny but smelt of petrol.

Can anyone explain what this could be or how it could be fixed? Thanks 🙂 

Photos:

https://drive.google.com/drive/folders/1VFv2ScAZgfGjfxZBwQ2-BkMmVSVY7901?usp=share_link

The hose is there to maintain a negative pressure in (what used to be called) the rocker box, by connecting it to the air intake.  I've always assumed that it's to help prevent oil leaks from that part of the engine and to prevent ecological contamination.  Unfortunately, it means that some oil is sucked into the combustion chamber (although not as much as is sucked in from the crankcase), and it goes through the piece of sponge.  Over time, the oil mist destroys the sponge.  I think it's only there to prevent objects being accidentally introduced into the air inlet when you change the filter.  I generally replace it with a cubic piece cut out of a bath sponge.

If it smells of petrol, then you may have petrol contamination of your engine oil.  Caused by fuel getting past the piston rings during the compression stroke, for example.  It may be time for a compression test if the petrol smell is very noticeable.