noticed today that theres still oil round the cap, so went for a spirited drive when i got back there is alot of oil around the cap again, not as bad as before but still alarming, i took the pcv valve in bits to check the diaphram and its ok but it doesnt look like a new one at all, very crusty oil etc they told me they had fitted a new one. should i take it back or just buy a new pcv and fit it myself? leaving the car etc is a pain