Coolant Issues

[k_u_n_t]

Hi, I was wondering if anyone here would be able to help.
I've had my 1.6 THP for around 6 months and during this time have experienced an issue with the coolant mysteriously running low. Every 2-3 weeks I'm having to top it up and its become a bit of a head scratcher as to why. I've had the water pump replaced as well as the cap for the expansion box and am still noticing this same issue, the garage also replaced a pipe in the cooling system previously as it had split and the coolant was quite literally pouring out. There are no visible leaks underneath or from anywhere that I can access just by opening the bonnet. The car runs fine and has never overheated, it sometimes has white smoke from the exhaust on colder days which stops after getting up to temp (so I'm praying this isn't a head gasket problem).

Has anyone experienced something similar that can maybe offer some peace of mind or reasons as to why this is happening? Thank you!

 

[Ed wales]

Radweld

 

[Charlie1875]

Thermostat housing would be the first thing to look at

 

[k_u_n_t]

Radweld

I've thought about using it but I'm nervous of it making the problem worse if the coolant is going somewhere it shouldn't be internally

 

[Pedro]

The white smoke is normally condensates burning off in the engine usually when outside air temps drop they can seem excessive also under no circumstances put anything in the coolant tank until you have had the system checked properly a pressure test will reveal if the head gasket is weeping other know failures are as already explained thermostat tank leak & possibly water pump related leaks there is a pipe which rums from the pump to the thermostat housing these are also know to fail at the joints
| suggest you also feel the bottom hose when the engine is warm if its cold then you have a thermostat issue