Overheating problem with my Clipper

Hi I could do with some advice on overheating as I've not had this problem before. After couple of weeks I noticed the cars temperature raising especially when going uphill. The last journey I went on 80 miles or so the temperature was going up all the time. I got where I needed to be by driving very steady under 2000 rpm and coasting where possible. I purchased a new thermostat and fitted it I've made sure the car has bled air out and topped up the level on the header tank but the car is still overheating. I checked the oil this morning and when I pulled the dipstick there was smoke coming from the dipstick sleeve. I topped the oil up this morning and the level is fine. I did notice when I pulled over that there was condensation around the header tank cap. A friend has said it could be the cylinder head gasket. Any advice at all will help.
Cheers.


Fueler

it could be many things

the head gasket being the worst but don't be to hasty

do you get a good strong fluid return to the header tank, should just trickly out a bit on tick over then when you rev it should become a strong squirt?

next drain the coolent and flush the system with a hose, down every pipe and into every direction around the system, through the radiator as well

if this is all flowing nicely then you know the system hasn't got a blockage

next with the thermostat out, look up at the impeller on the pump, is it in tack? put you finger on it and turn the pulley does it spin or just slip

if it slips the impeller could not be turning thus not pumping around the system

check your thermostat in a pan on the stove, to make sure it opens fully

a few things to check first

Hi thanks for your reply. When I changed the thermostat I flushed the system so all ran clear. The water pump seems to be working fine as there is a a good stream coming into the header tank on tick over. I will try the thermostat in hot water but I think it's working as the bottom radiator pipe was cold when the car got up to normal temp and then hot after a 15 min journey. I'll try it any way and then post back.

do your coolent pipes get hard? as in alot of pressure in the system