Engine overheating

[Jack.L.89]

Help please guys,

 

My 1994 Rav 4 keeps getting a hot engine while in idle, low speeds and city driving. On top of this the heating doesn't work and the cooling fans don't run. While driving at high, consistant speeds the engine cools, but I think this is just from the air running into the engine running the fans. Any ideas on what the problem might be so I can fix it?

[IanML]

Assuming you have checked the coolant level and eliminated the possibility of air in the system, one has to suspect a severe problem in the cooling system.  Perhaps the water pump is not running - impellers can corrode away.  Alternatively, the system is clogged up and needs draining and flushing.  My money is on the water pump, because it would not cool much if the system was clogged, even when airflow across the radiator was high, whereas convection cooling is still possible with a defective pump.  Only one way to find out.

I haven't mentioned the thermostat, because the heater should give some output with a closed thermostat, as the heater circuit normally bypasses the thermostat.

[Jack.L.89]

Thanks Ian, will check and hopefully that should fix it. 

[Bernard Foy]

I don’t know what heating system you have but it used to be normal procedure to replace the thermostat at the same time as replacing the water pump.