156 Coolant system

[jpapiki]

I have Alfa 156 Twin spark i have replaced coolant bottle old one had a leak it was driving but keep overheating thought new one will fix the over heating issue, is any one have an idea since it seem like circulation is not taking place properly

[colcol]

Check the thermostat, as if they are more than 10 minutes old, they are most likely faulty, they usually open early and the car runs too cold, but just to trick you, they sometimes open late or jam shut, check post tonight about thermostats, Colin.

[jpapiki]

Which termostat as it has one on radiator and saw switch on water pump, which one must i check?
Or advise the surpport fuse for termostat. 

[colcol]

The thermostat is on the end of the cylinder head next to the battery, they are known to fail, the thermoswitch is electrical, sits on the radiator, it switches on the electrical fan on the radiator, just have the car idling and have the bonnet up and see if the fan switches on and keep an eye on the temperature gauge, these switches also fail, also known as thermo resistor switch, Colin.

[jpapiki]

I have run the engine and checked termperature just when TEMP reaches 91 degrees fan runs Temp keeps going up till red led flashes and fan sound goes faster then water boils but not passing through them switched engine off for few minutes and run it again keep persisting. just wana be sure before i can replace the Thermostat.

[Mick A]

Stop running the car until it boils. You will damage the engine.

Is the hose from the thermostat to the radiator hot or cold?

[jpapiki]

The hose is getting Hot and seems raising a bid with air, did replaced the thermostat problem persist, i also did test before replacing i pawed boiled water and it did opens but i just replaced it i am confused of how to run water pump test? The engine Temp is still passing to 120 degrees

[Mick A]

Well now it is either a faulty water pump, a blocked radiator, or a blown head gasket.

I will say this again, STOP running the engine until it overheats! You WILL destroy the rings or blow a head gasket!

[jpapiki]

Yeh you might be right,
What could impact the gasket and which gasket could be affected, what are the most common symptoms of this failure.Radiator flush is done water is passing correctly just coolant circulation is the issue.

[jpapiki]

If Gasket is blown shouldn't it mix water and oil and consume a lot of water?Does water pump operates manually depending to engine turns or does it have an automated function to operates

[colcol]

If head gasket is leaking, then you will have coolant in the oil and oil in the coolant, the coolant will be a milky color, a compression test will confirm if your head gasket is blown.
The water pump is driven off the camshaft belt, so as your engine runs, the pump pumps the coolant around the engine, water pumps should be renewed at every 2nd camshaft belt change, Colin.