Coolant Question?

[mudski]

Interested to know how coolant flows through a closed thermostat?

There is a small by pass next to the thermostat so when its closed water still can flow. Otherwise the system will pressurize from the water pumps continuous force.
Or something along the lines of that.
On a lot if jap and american truck engines they use a rubber hose as a bypass, on cars it's usually built into the casting of the engine.

[Parksy]

Cheers. I only ask because I had the same problem, it turned out I didn't have a thermostat at all. When I installed a new one, I didn't get any more flow out of that hose. Mind you I checked it when cold.

[nissannewby]

There is a small by pass next to the thermostat so when its closed water still can flow. Otherwise the system will pressurize from the water pumps continuous force.
Or something along the lines of that.
On a lot if jap and american truck engines they use a rubber hose as a bypass, on cars it's usually built into the casting of the engine.

Basically this

[Col.T]

Graeme,
I get the impression that your thread is based on curiosity rather than a hard problem.
If coolant levels are good, engine temp. is good and there is love and good vibes all over, I'd settle with the Happyman's explanation and sleep well.
Cheers
Col

[graeme1969]

Gday,

Changed the thermostat today fitting an original. When I started it up there was no flow from the tube which was continuously flowing previously. The flow only started from there once it was pretty much up to temp. It looks to me as the old thermostat is stuck open 2-3mm, and looking at the layout of the thermostat cover I reckon that there should only be flow through that tube if there is flow through the radiator which should only happen when the thermostat opens. Shouldn't it?

[Parksy]

That was my assumption too Graeme. But glad you got it sorted.

[graeme1969]

Gday,

The temp gauge definitely sits higher (about 1/4) than it did previously. Time will tell whether this is going to be a good or bad thing, depending on how well it can maintain more of a stable temp I guess.

Below is a pic of the old thermostat which still looks to be in very good condition. Out of curiosity what does the bottom spring valve achieve in the operation of the system?


Graeme

[nissannewby]

Gday,

The temp gauge definitely sits higher (about 1/4) than it did previously. Time will tell whether this is going to be a good or bad thing, depending on how well it can maintain more of a stable temp I guess.

Below is a pic of the old thermostat which still looks to be in very good condition. Out of curiosity what does the bottom spring valve achieve in the operation of the system?


Graeme

The bottom section closes off a port in the housing which will allow fool coolant flow through the radiator, when its cold this port is open and the coolant flows around the head without going back through the radiator, this allows quicker warm up as less wear occurs at operating temp. As it warms up and gets hotter it obviously closes that port and allows full cooling effect from your radiator.