Technical Cooling system problem

[Mike1alike]

Then, he opened the heater bleed valve and blew into the coolant reservoir with his mouth to force the liquid out of the heater core. Is that the right way to do it?"

Question: doesn't the needle on your temp gauge have a visible movement? Like when it's getting hot and needle reaches halfway mark on the gauge and thermostat opens. Does the needle go back 1 line or 2? If it does, that's a clear sign of air trapped inside the system.

 

[Sabbas]

Not the way I would do it it, but probably works to a certain extent. If he had my equipment he could do it more professionally.
Alternatively as I said , with engine warm it is under pressure already as long as the pressure cap is screwed down so when you open the bleed screws then the air will come out.
Another very important thing to consider is why you have a pressurised cooling system in the first place. It allows the engine to run at a slightly higher temperature where it is more efficient whilst still keeping a safety reserve.
Note, it is not the high temperature which damages an engine, it is when that water/coolant boils and becomes a gas, at which point any localised hot spots can rapidly exceed the normal boiling point of water, it is why pressure cookers work.
Remember for every lb of pressure above the water in a pressurised cooling system it means the water boils at 1.5 degrees Centigrade higher than the normal boiling point of water at sea level of 100 Degrees Centigrade, so a 10lb rad cap will allow the water to reach 115 Degrees Centigrade before boiling and causing damage, so with your coolant system the rad. cap which is almost 1.Bar pressure it means that the water could be 122.5 Degrees Centigrade without causing damage. However once you open that rad cap the water will instantly boil causing damage, you mentioned a temp reading of just roughly 98 Degrees Centigrade from your OBD scanner so if that is correct it would mean the water /coolant if you opened the pressure cap would be just about to turn to a gas! So not a good idea to remove the rad cap on a hot engine.
Many times in the past I have seen a motorist drive in to the forecourt with a hot engine release the rad cap and the next thing a jet of steam and water shoot out as he jump away dropping the rad cap, what often then happens is the idiot grabs the watering can and puts cold water into his hot engine with a very good chance of cracking the aluminium cylinder head.

Good morning. You are amazing, thank you for the knowledge and information. I finally got in touch with the mechanic, and I will take the car in on Friday for him to check it. I mentioned all the symptoms regarding the temperature and the radiator fan, and he suggested replacing the temperature sensor. I will keep you updated with any news.

 

[Mike1alike]

Good morning. You are amazing, thank you for the knowledge and information.

He's this guy!

 

[bugsymike]

Good morning. You are amazing, thank you for the knowledge and information. I finally got in touch with the mechanic, and I will take the car in on Friday for him to check it. I mentioned all the symptoms regarding the temperature and the radiator fan, and he suggested replacing the temperature sensor. I will keep you updated with any news.

In the motor trade since 1969, trouble is forgetting more now.

 

[Mike1alike]

and he suggested replacing the temperature sensor.

I would say that is nonsense! Sensor you have shows the correct coolant temperature, it is not sending any wrong data. Plus... the thermostat is mechanical. It doesn't open according to temp told by sensor, but to coolant that hits it temperature. Having air in that point in the system makes it go different than it should.
Sensor's temperature is used by ECU to do proper fuel/air management correlated to engine's temperature and to run the fan so it would keep the coolant temp within the correct numbers. And it does that right, ECU runs the fan having high coolant temperature. Problem is it can't keep it right if there is air inside cooling system. And really, that technique used by mechanic is no guarantee there is no air inside.

 

[Mike1alike]

trouble is forgetting more now.

You know too much, Bugsy!

 

[bugsymike]

You know too much, Bugsy!

Now you are accusing me of being a "Know it all".

 

[Mike1alike]

Now you are accusing me of being a "Know it all".

Neh, not like that...!
You just know. A lot!

 

[bugsymike]

Neh, not like that...!
You just know. A lot!

Not as much as I have forgotten.

 

[Mike1alike]

Not as much as I have forgotten.

Just call that "Declutter" and you're fine.
I'd say that if you'd need to remember something it will come back to you.

 

[bugsymike]

Just call that "Declutter" and you're fine.
I'd say that if you'd need to remember something it will come back to you.

Ha,ha, what 's your name, come to that what is my name?

 

[Mike1alike]

what is my name?

You're not there... Are you?!

 

[bugsymike]

You're not there... Are you?!

Never have been all there.

 

[Mike1alike]

And one little detail about the system and bleeding it, you did ask and I forgot to mention.
It makes no difference if you have it on hot or cold when you bleed the system or if you turn the heat on or not.
Because coolant goes through heater all the time, nothing stops that flow. Selecting between cold and hot only directs the air which way to go, moves the blend door, that flap that chooses whether air goes through the heater core or the evaporator thus making it hot or cold.
If there's air trapped inside the heater, there will be no or very small amount of heat coming out when you turn the heat on. Same thing happens with air trapped inside radiator, coolant is not cooled enough there making engine run on higher temperature then.

 

[bugsymike]

And one little detail about the system and bleeding it, you did ask and I forgot to mention.
It makes no difference if you have it on hot or cold when you bleed the system or if you turn the heat on or not.
Because coolant goes through heater all the time, nothing stops that flow. Selecting between cold and hot only directs the air which way to go, moves the blend door, that flap that chooses whether air goes through the heater core or the evaporator thus making it hot or cold.
If there's air trapped inside the heater, there will be no or very small amount of heat coming out when you turn the heat on. Same thing happens with air trapped inside radiator, coolant is not cooled enough there making engine run on higher temperature then.

As you say, I know older cars had a valve to turn off the heater flow, but car manufacturers realised they could save money by using plastic flaps to direct the air flow and by using the heater matrix/radiator as an extra cooling source they could get away with smaller main radiators.

 

[Mike1alike]

As you say, I believe older cars had a valve to turn off the heater flow, but car manufacturers realised they could save money by using plastic flaps to direct the air flow and by using the heater matrix/radiator as an extra cooling source they could get away with smaller main radioators.

They did have that valve, yes.
But I don't see the modification as being brought by possibility of saving money, after all a valve is cheaper than the flap. I see it as an improvement to the system. Having that side closed by valve for about half a year would allow some inside degradation and long time I think it's better for it to have a constant flow than being closed for business half of year.
Radiators are smaller, but... if they are clean inside, no path clogged and if cooling system is in good condition, they do work really well, they do give enough heat when needed.

 

[bugsymike]

They did have that valve, yes.
But I don't see the modification as being brought by possibility of saving money, after all a valve is cheaper than the flap. I see it as an improvement to the system. Having that side closed by valve for about half a year would allow some inside degradation and long time I think it's better for it to have a constant flow then being closed for business half of year.
Radiators are smaller, but... if they are clean inside, no path clogged and if cooling system is in good condition, they do work really well, they do give enough heat when needed.

Maybe I am more cynical than you, although I did read that it saved them money on coolant radiator capacity in a trade journal.
As an apprentice heater valves were common, both under the bonnet sometimes as a tap then others cable controlled, then cable controlled inside the car by the heater matrix before they finally went to just heater ducting flaps.

 

[Sabbas]

Good evening. I just got back from the mechanic. The thermostat has been replaced with a new one, as well as the temperature sensor. The mechanic performed the bleeding procedure twice. He filled the coolant reservoir above the "max" line, opened the radiator bleed valve until the coolant flowed steadily, then opened the heater bleed valve and blew air into the reservoir by mouth until a steady stream of coolant came out of the heater. Unfortunately, the car is still reaching 98 degrees and the temperature does not drop below 96. At this point, I don't know what else to do.

 

[bugsymike]

Good evening. I just got back from the mechanic. The thermostat has been replaced with a new one, as well as the temperature sensor. The mechanic performed the bleeding procedure twice. He filled the coolant reservoir above the "max" line, opened the radiator bleed valve until the coolant flowed steadily, then opened the heater bleed valve and blew air into the reservoir by mouth until a steady stream of coolant came out of the heater. Unfortunately, the car is still reaching 98 degrees and the temperature does not drop below 96. At this point, I don't know what else to do.

Does it actually lose any water?
If not then I would look at the water pump and the new radiator to see if they are working efficiently.
Radiators can look the same but be for a smaller capacity engine so not able to get rid of heat, although if radiator fan is running continuous I would have thought it should help?
The other thing is some water pumps have plastic impellers which if they fail will not circulate the water properly

 

[Mike1alike]

Good evening. I just got back from the mechanic. The thermostat has been replaced with a new one, as well as the temperature sensor. The mechanic performed the bleeding procedure twice. He filled the coolant reservoir above the "max" line, opened the radiator bleed valve until the coolant flowed steadily, then opened the heater bleed valve and blew air into the reservoir by mouth until a steady stream of coolant came out of the heater. Unfortunately, the car is still reaching 98 degrees and the temperature does not drop below 96. At this point, I don't know what else to do.

Meaning it did exactly the same thing he did first time, not bleed the system properly.
Was the engine hot while he did that? Thermostat opened?

Do as I advised above and tell us if there is air coming out. After driving the car, stop the engine and open the breathers. Carefully and only a little. Start with the radiator's and do the heater's second. If air comes out wait until coolant comes out, then close the breather's cap.