Door lock problem

I'm having trouble with my drivers side door lock. It just doesn't want to unlock when i use the key. It started off where i would have to turn the key a few times until it would work but eventually it did. Now it has got worse and the key doesn't want to turn at all. It unlocks fine when you pull the knob inside most the time, sometimes if i have been trying with the key the knob won't pull up untill i have pulled the door handle first. Anyone else had this or know what it might be?

WD40 the inside of the tumblers by poking the spray tube inside the key slot.
insert key & turn it till it starts unlocking BUT DONT FORCE IT.
if that doesnt work, you might need a new lock barrel.

ok thanks, i'll give it a try

worked a treat

Now put some OIL in the lock. Otherwise it'll bugger up again as WD is not a lubricant.

ok thanks logi

I only put keys and graphite powder IN lock barrels, oil or grease everything outside them.

yeah i was thinking of graphite powder, do you think it will be ok now that ive sprayed wd40 in there? or do you reckon it will clog up?

Never tried - but if WD is still in there, the powder will clog in it. Might be best to give it some time to drain away.

WD and duck oil are great at what they do, but they are water-dispersant and short-term lubricants, best to read what it says on the tin.