Repalcement Motor

[Jules]

Very interesting reading this, I will still buy me a diesel Patrol 4.2 SUV oneday when the time is right. It is just very interesting that you guys downgear to let the temp come down ( is it the same for a PETROL engine ). I have seen and experienced where a vehicle nearly overheat then you put your aircon on HEAT MAX and the enjin temp goes down??

Jules

[tour de frans]

Hi Jules
The diesels work different to the petrol,and if you shift down you up the rpm but allso your foot lifts from the throttle to maintain the same vehicle speed and there for the egt's cool down.Higher or lower rpm do not affect the egt only load.(your right foot.)
The hot enjine that cool down with the aircon,should be the otherway arround.If your aircon is working the condensor gets hot and sits infront of the radiator,witch create a hot spot infront of the radiator.By turning the ac off will help the car to cool down.But what you said by turning it on ,cool the car down,(was it a Patrol?)are allso true.Most cars and Patrols have a safety in the cooling system.It is a sensor that will switch the ac pump off and only the pump,it will not cut the electric fan infront off the radiator.That is the same fan that came on when you turn the ac on.So the pump is not pumping there for no heat from the condensor,but a extra fan is running that same moment and that help to cool the car down faster.
Hope it help.
Rdgs
Frans

[Gerrit Loubser]

I have seen and experienced where a vehicle nearly overheat then you put your aircon on HEAT MAX and the enjin temp goes down??

Do you mean that you turned the heater to max, Jules? If so, it makes sense that the engine coolant temp would drop: the interior is heated by the engine coolant. You are taking heat energy out of the engine coolant to heat the interior, which lowers the coolant temperature (you boil in the cab instead of your engine ).

[Jules]

Frans no not a Patrol was sommer n gewone small karretjie, thanks for the correction Gerrit yes it was the heater of the vehicle that we turned to max heat. At least we could feed ourselves with ice cold beers but we were rather worried about overheating the engine.


Groete
Jules