23-06-2013, 08:53 AM
As Darren said...
Because the heater matrix provides a restriction to the flow of the water around the engine, if you block it off completely, before the thermostat opens, you won't get any water flow around the engine, it has nowhere to go, so anywhere that is creating more heat than another place - you get hot spots...
Bypass it by putting in a Thru Piece - you end up sending ALL the water around the bypass, even when the thermostat opens up, it's easier to flood water through the bypass than it is to move it through the radiator, meaning the red hot water that's been round the engine just keeps getting pumped through a pipe, not actually going through the radiator..
Some engines are designed to not have heater matrixs connected all the time - ala VW engines and Ford engines, they have actual valves on the pipes to stop the flow, but you will damage a PSA engine doing it, the amount of times I've seen XUDs with bypasses and they're always saying it overheats, runs badly etc, then wierdly the head gasket goes..
Because the heater matrix provides a restriction to the flow of the water around the engine, if you block it off completely, before the thermostat opens, you won't get any water flow around the engine, it has nowhere to go, so anywhere that is creating more heat than another place - you get hot spots...
Bypass it by putting in a Thru Piece - you end up sending ALL the water around the bypass, even when the thermostat opens up, it's easier to flood water through the bypass than it is to move it through the radiator, meaning the red hot water that's been round the engine just keeps getting pumped through a pipe, not actually going through the radiator..
Some engines are designed to not have heater matrixs connected all the time - ala VW engines and Ford engines, they have actual valves on the pipes to stop the flow, but you will damage a PSA engine doing it, the amount of times I've seen XUDs with bypasses and they're always saying it overheats, runs badly etc, then wierdly the head gasket goes..
