Removed mine and no problems. Only thing is that every once in a while I will hear the water flowing through the heater core. Not a bother though.

 

This is only true without flow. With high flow rates on some GM 4 cyl engines for example, you can have 90psi+ in some parts of the system, generally within the engine itself. You cannot exceed pump output pressure+static pressure, so if 12psi static and 60 psi pump output, you could have 72PSIG at the pump outlet, and less the further you go downstream, back to less than 12 at the pump inlet. For example. That valve is not a pressure regulator, though, it's a flow reducer. Reducinig flow DOES also reduce the pressure at the heater core, especially the intlet tank end.

The reason for using a flow restrictor or 'H-valve' bypass in the heater circuit is to prevent heater core flow from exceeding a certain value, to reduce erosion corrosion. So, removing that valve will shorten the life of your heater core. Flow noise will be increased with higher flows, too, as mentioned.

 

Can I get an update on this. My heater core restrictor broke today when I replace my leaking heater hose. I put a 3/4" plastic coupler in it's place. Anyone have any problems yet running without the restrictor? I'm running a Meziere HD Electric Water Pump. I wonder if that makes a difference since the flow is consistant. Maybe the pressure wont be as much as with a mechanical pump at higer rpm's. I definately do not want to damage the heater core. Should I put the stock restrictor back on? I can probably pick one up from the dealership if needed.

Thanks

 

I'd say if you are worried about it then reinstall a new flow reducer.