Water temp fluctuating

[swampydrill]

The water temp on my friends car regularly goes from very low to very high, when it goes very high the heating in the car goes cold and when the water temp goes low the heating goes high. He was told by a garage that his cylinder head gasket needed changing, this has been done
and the water pump seems to be ok as well, has anyone got any suggestions.

 

[tryingnottobeafool]

get rid of car as it sounds as if crack in engine bock/ head or sleeves in cylinder cracked / broken

trade it in

 

[Stivino]

Don't do anything hasty just yet.

Could you post some more info about the car. Make, model, age mileage etc.

 

[swampydrill]

Seems to be getting better so may have been air

 

[tryingnottobeafool]

just depends how much water your going through

to get rid of air turn engine on

put heater to max speed

put the heater on the hottest setting

let car idle for 15 minutes

 

[^neo^]

just depends how much water your going through

to get rid of air turn engine on

put heater to max speed

put the heater on the hottest setting

let car idle for 15 minutes

How does that get rid of an air lock?

 

[tryingnottobeafool]

by the travel of water round the system

you can also squeeze a hose a couple of times to help but above works

 

[freeflyer]

airlocks vary from car to car.. turning the heater on and running for fifteen mins may work one one car.. although i have no idea which one

There are numerous ways to get rid of airlocks.. one of the most popular is to jack up the front of the car as high as poss, and run the engine with the rad cap off for ten mins..

 

[tryingnottobeafool]

if its good enough for Haynes manual its good enough for me

 

[KingboyD]

airlocks vary from car to car.. turning the heater on and running for fifteen mins may work one one car.. although i have no idea which one

Some old Honda`s had a tap on the heater matrix hose opperated by the heater control