Golf MK4 SDI with 02K gearbox - Can't select 1st gear after leaving car standing - ChiefCakeEater
If I drive everyday then no problems. But if I leave the car standing for a day or two then it drives fine for 5 miles, then I have trouble selecting 1st or 2nd after stopping at traffic lights. After driving another 30-40 miles the problem goes away again, and I can select 1st and 2nd after stopping at traffic lights.

I don't need to drive everyday so this is a real pain. After 5 miles when the problems begin, if I try to select 1st it just won't go, and I can hear the engine labouring ever so slightly when I try to select the gear. At this point the only way I can select 1st is to let the car roll forwards if I'm lucky enough to be facing downhill, or move the car forward a little in 3rd gear, then quickly select 1st. The only other option is to stop the engine, engage 1st, then restart the engine with the clutch down.

Please has anyone got any ideas? This is driving me mad! And the intermittent nature of the problem is very confusing for me.
Golf MK4 SDI with 02K gearbox - Can't select 1st gear after leaving car standing - Collos25

Sounds like the clutch plate is on the way out.

Golf MK4 SDI with 02K gearbox - Can't select 1st gear after leaving car standing - thunderbird

Had this on a Golf many years ago, warped clutch plate. Luckily for me replaced under warranty.

Coud also be linkages need adjusting or possibly the balls on the linkages are worn. Much cheaper than a clutch but very time consuming.