Hi,
Your problem sounds very similar to one I have on my 2001 RR 4.6. Warm AC and no fault code on the HEVAC, by pass compressor which runs fine. My faultmate didn't indicate anything as well. I had this last year and had the system re-gassed. This worked well for a few months then by the end of the summer it was warm again. AC guy said it's a leak somewhere and best bet is the condenser. They tend to go in the top left corner when viewed from the front of the car. As Dye was injected last year I took the panel off above the rads to get a better look last weekend. That corner of the condenser had a lot of green oily gunge around it. So condenser is shot. I'd think yours might be too. Another very common issue on the P38.
I ordered a new condenser and Dryer which both arrived today so I'll be swapping them out over the weekend then getting a re-gas next week if possible. Job looks simple enough, though I might write a walk through with pictures if anyone is interested.
Suggest you remove the grille and panel that covers the rads (4 x M8 bolts) then have a good look at the condenser for oily residue in the corners. Since the OE condenser is so prone to failure and expensive from a dealer I decided to buy an aftermarket condenser and a new dryer. Condenser was £88 and Dryer £50. Last re-gas by a mobile AC guy was £50 and I expect more or less the same price this time.
LW
.
