Technical temperature rising when driving on flat road [Solved]

[flisko]

my old 55s mk1

temperature rising when driving on flat road, probably bad thermostat doesnt open fully?

also fan doesnt come on when temp gauge goes over middle, connected fan directly to battery and it spins, is there any way of knowing which sensor went bad, the one on intlet-blue or the one on radiator

 

[flisko]

just changed both sensors but fan still doesnt come on when temp is above middle
connectors to sensors dont appear to be melted or anything
wiring?

 

[flisko]

Disconnecting blue water temp sensor on inlet doesnt do anything when engine is on, mhm
a new journey beggins

 

[flisko]

yea sure haynes

 

[flisko]

while changing thermostat also found out water pump was leaking, that explains minimal coolant loss over few months

original factory fitted thermostat 20 years ago? cant believe it lasted this long if it is infact the first one

 

[flisko]

is one of these two relays located behind interior fuse box supposed to be for radiator fan? changed both of them anyway so we will see

 

[tinytim]

There should be sufficient air flow through the radiator when moving to cool the engine so your problem may not be the fan; coolant loss plus overheating suggests head gasket failure.
To test the fan just let the car idle when stationary and increase engine load by turning everything electrical on with the heater off ensuring coolant is topped up and system has been bled. The temp gauge will usually approach the red before the fan kicks in.........

 

[flisko]

temp rising was due to bad thermostat which didnt open fully when temperature was high -tested thermostat in pan
coolant loss was due to water pump leaking
fan didnt turn on due to bad relays, dunno which one is for fan but i replaced both of them (pic above) and fan now works normally

 

[tinytim]

Well Done! Always difficult when more than one problem; also watch out for a leak from the metal pipe that goes from the water pump to the rubber hose. This corrodes at the back where you cannot see it.......