Ford Fiesta flight 1.3 2002 3d - hot air overheats only after engine restart - Arthur33
the hot air on my old fiesta overheats dramatically if I stop and restart my engine

I can drive 10 or 100 miles and cool air is no problem. If I stop and restart air blows roastingly hot regardless of settings. Even with the blowers off hot air passively fills the car. Problem resolves after engine fully cools.

The engine itself does not obviously seem to overheat. Bonnet normally warm, no white smoke, no warning light (this model does not have a temp gauge)

Coolant does need topping up more than I expect but no obvious leak.

please solve my mystery - what would you try first?

spec: ford fiesta flight 2002 (1995 to Mar 2002 model) 1.3 petrol
Endura E engine (afaik) had it about a year. Full service when I got it.
Ford Fiesta flight 1.3 2002 3d - hot air overheats only after engine restart - madf

Low coolant due to Head gasket failure - or radiator valve failing.

Sounds as though thermostat is failing as well?

Any white deposits under cap when you top up the engine oil?

Ford Fiesta flight 1.3 2002 3d - hot air overheats only after engine restart - Arthur33

Low coolant due to Head gasket failure - or radiator valve failing.

Sounds as though thermostat is failing as well?

Any white deposits under cap when you top up the engine oil?

Thanks, no obvious signs of water in the oil, no deposits, no sludge on dipstick. Hard to judge power as it's an old small car. Coolant loss is maybe 2-300 mls in last 2 weeks, is that excessive? I don't understand why, if related to engine temp, it doesn't occur with work of the car. If I drive >70 miles over the Pennines fine till I stop for 5 mins and restart. Same if I go 3 flat miles to the shop. am I right that to get hot air with a normal engine temp the air from the grille needs to be going through the heater matrix. if it is blowing cool as per my settings why would it then blow hot if I stop and restart the engine? is the ventilation used as a 'exhaust' from the coolant if too hot? why then doesn't it occur while driving as the engine heats?
Ford Fiesta flight 1.3 2002 3d - hot air overheats only after engine restart - elekie&a/c doctor

Sounds like the heater control valve faulty.Very common fault on this age Fiesta.Air for the heating system enters the car via the vents in the body,just below the windscreen,by the wipers.