low oil pressure warning!!

[w-s-m passat]

i was driving on a motorway yesterday and i had a low oil pressure warning appear and sound on my dash.
there was no altration in performance / mpg / or any dodgy engine noise.
this fault seems to be intermittent as it sometimes clears before i can stop, or clears when turning ignition off/on.
RAC man told me possibly a oil pressure switch but not 100% sure.
does anyone know where this switch lives, or know any other reason for this fault?? all help greatly appreciated.
forgot to mention i have a 1.8t 20v s estate 02 reg.
thanks

[Golfer7]

This is something I have come across a few times, usually more common on 1.8T's the oil pump strainer/pick up gets partially blocked with black sludgy carbon deposits...
Try taking to oil pressure readings when vehicle is hot...
In past cases I have replaced complete oil pump with new pick up & replaced oil filter with fresh oil.
Have heard of people just cleaning/replacing oil pick up and cured problem, but for the sake of going through removing lower sump pans & resealing I wouldn't want to do the job twice or pay twice...
Hope this info helps

[LvR]

To check for sludge problems look for carbon deposits under/on your oil filler cap. I suppose your oil level is ok, so besides the above mentioned cause a blocked oil "filter" from black sludge inside the carter pan (near the oil pump) can be the cause too, BUTTT first of all, check your oil filler cap and look inside your valve cover for carbon deposits/black sludge.

[w-s-m passat]

thanks for the info guys, you were spot onwith the carbon build up!
car is now back running spot on again.

[LvR]

Not at all; glad to hear that your problems are gone