Audi A3 TDI - losing coolant fast

Just started yesterday n coolant light came on. Checked reservoir n below minimum so topped up.went again quite quickly

Noticed that the blue coolant cap does not tighten or nip right up when you tighten. Also seems very loose inside. I know they form a seal to pressurise the system so could coolant be leaking as result ?

Also noticed slight bit of water on driveway under driverside so could this be a cracked pipe as opposed to the head problem as described on here?

going to get it pressure checked later as well as getting new coolant cap as that can't help. the fact there is a leak on the driver side could mean a split pipe?

its got 60k miles on it, 06 built and recently had the cambelt done (about 500 miles ago). water pump was checked and ok but could go at any time i guess.

thanks, Nick

right. checked the head and its a C code so that is good news.

water is under the drivers side and on the floor dripping so I am thinking water pump or rad.

I won't be impressed with the garage if it is the water pump. I just had the cambelt and full service done and asked specifically if water pump was done. to which I got 'no we checked it and its fine'

back its goes then and they can wear the labour as it has failed about 2 weeks later and 300 miles down the road. less than ideal!!

Rad it was Jazz. put it up on ramps, had the sump cover off and it was obvious.

in the far left corner and some fluid had crystalised.

flushed the system, put some new coolant in with rad weld and fine after 50 mile trip. fingers crossed it holds up til i get back from the states.

new rad is defo on the cards though.