Hi All,

A problem with my Accord - 4Cyl Auto F20Z1, right hand drive, 270k miles.

Engine overheats and coolant comes out of the radiator cap and overflow reservoir.

Engine idle for 10-15 minutes, needle reaches just below middle, both fans come on for a minute or so.
Keeping engine running both fans will come on and off - I think this is quite normal.

Driving the car and as long there are no traffic jams the temperature remains normal - needle just below middle.

When engine is switched off (keys out) after a drive the condenser fan comes on for a few minutes - I think this is quite normal.

During a long drive if get stuck in a traffic jam the temperature goes up to 3/4 and and a bit higher before the fans come on (shouldnt fans come on immediately the temperature is over 93c /199f degrees? ).

Sometimes to bring the temperature down i switch the heater on full speed - the temperature goes down to normal very quickly.

I expected both fans to come on and stay on until temperature goes back to normal, that is when the ECT sensor A opens - temperature drops below 93c / 199f. In other words to behave the same way as when engine idles.

Any suggestions and hopefully solutions would be appreciated as this is driving me crazy.

 

A new thermostat may be necessary. Sometimes thermostats get "lazy" and fail to open fully from a closed position. Everything else seems to be working.


A possible but less likely scenario is a small head gasket leak that allows exhaust gases into the coolant under sustained heat load.


good luck