Hey guys, sorry if this is a long story

first of all ive got a 1995 import sti (redtop) on 85k, with only air filter and dump valve mods to the engine.

i noticed this about 3 weeks or so ago my temp gauge was going up above the 3 quarter mark, but only really if i was stationary or moving very slowly. so i let my car cool down and check header tank and it was empty as well as the filling tube by the battery. so i topped it all up with water, drove the car for about 2 weeks and it was fine, no overheating, the filling pipe was empty but the header tank was still full, so just topped up again and everything still ok.

i took it for a service 2 days ago and the same thing has been happening since, temp gauge just going up and down. there is a little bit of scum on the header tank cap but the oil cap and dipstick are fine. the garage did say i had a slight leak on the radiator and coolant was bubbling over slightly but the temp gauge was going up the same day of the service after it was topped up with coolant.

heaters are blowing hot and cold fine

it also failed the MOT on emissions as its running very rich due to faulty lambda, dont know if that would affect it at all?

Any advice would be awesome, thank you

 

radiators leaking so replace this and re-check

 

same as steve replace rad would be first thing wouldnt think that the lamba sensor would make it heat up like that could be wrong like but shouldnt think so would also check ure header cap mine was leaking a while back found it was the seal on the cap

 

ok, ill change rad and caps and see how it goes. hope its not HG.