Coolant And Heating Problems

[yaris781]

hi

im hoping someone can help me recently thr Mrs's Rav was not blowing warm air unless it was being driven and when stationary would go cold. we gad the thermostat replaced and its still same ok when driving and cool when stationary.

since the thermostat was replaced was topped up with fresh new coolant. weve now noticed that every other day the temperature needle seems a bit higher than normal and heater is cool this is when its stationary as you start moving its back to normal.

the second issue is that shes having to top up the coolant every fortnight about half a bottle of coolant yet there is no visible leaks.

one garage said it was head gasket another said it wasnt another said it was radiator

so confused as seem to be getting different diagnosis from everyone

as ever please any advice would be greatly appreciated.

other than that the Rav is fantastic would really like to get it sorted before the extreme weather sets in

thanks in advance

[Awebb180]

Is it a petrol or diesel?

what is the age and service history of the vehicle?

Alex

[yaris781]

hi alex

its a petrol 2.0 vvti 2003 serviced every 12 months when mot is due does about 6k a year weve had it for about 9 years only recently noticed that the heater was not warming up when stationary.but was fine when driving.its using about half a bottle of coolant a fortnight or so with no visible leaks what so ever

we had the thermostat replaced and its still the same.

one of the things that someone has suggested that its possible the new thermostat could be faulty?????

[CharlieFarlie]

You can check your stat by feeling the temperature in the hoses.. Once the car is up to temp all the hoses should be around the same temperature IE fairly hot... It is possible the new stat is faulty but fairly unlikely.. Could it be the heater matrix getting a bit blocked so not flowing water as good as it used to ?

[yaris781]

You can check your stat by feeling the temperature in the hoses.. Once the car is up to temp all the hoses should be around the same temperature IE fairly hot... It is possible the new stat is faulty but fairly unlikely.. Could it be the heater matrix getting a bit blocked so not flowing water as good as it used to ?

hi

ok no ones mentioned the heater matrix so could be worth checking.

[Tech01]

A radiator which is "on the way out" - i.e. partially blocked - will show up as hot in some areas, and cool in others. CAREFULLY move your hand over the radiator surface, and if you find hot and cold spots, then suspect the rad.

If you have lots of white smoke from the exhaust, it suggests the engine is "burning coolant" (antifreeze) - which usually means head gasket gone. Bubbles in the coolant tank, or coolant smelling of exhaust, also signs of the same thing.

Might be worth doing a clean-out of the cooling system (Liqui-Moly products work well). Flush out with clean water before and after using the cleaner. Refill (when all is sorted) ONLY with recommended type of antifreeze (do not mix makes or types), diluted (if necessary) ONLY with distilled/de-ionised water, never tap-water.

Chris