Electric Water Pump, engine

Making an increase in the velocity of water flow in a cooling system often does not improve the cooling ability or efficiency of a closed circuit cooling system like that in a vehicle engine.

This can be demonstrated by removing the thermostat, which in effect is a restrictor that regulates coolant flow to maintain a preset temperature. Removing it can cause coolant to flow to more quickly through the radiator which is the heat exchanger, the coolant flow is too quick to allow sufficient heat exchange from the coolant to the radiator structure and the passing/surrounding atmosphere.

It would help if you tell us what vehicle and what condition/s are that are causing the overheating.

Rod, G'day, trialled one of them a few years ago on a Patrol 2.8 TD, could not get it to cool the engine properly at all. Eventually got my money back. In certain applications I think that they can be effective, but not in the application I was looking at. Good luck.

The only time an extra water pump will improve cooling, is if your engine is working very hard at low revs i.e when the mechanical water pump is turning slowly.

G'day Rod,
I have a landcruiser 1996 1hz with DTS t/c and 3" exhaust. I have had overheating problems since new. Just enough to have the a/c stop working efficiently but not cook the engine.
On long hills towing the caravan as someone said, your revs drop and so does your water pump slow down. In soft sand fully loaded with reduced tyre pressures was another case. You may be able to drop back a gear to get your pump up to speed but I would usually back off the load.
I have recently replaced the radiator, and have also fitted a thermostatically controlled Davies Craig electric water pump on the bottom hose. It cost about $250 at super cheap, made in Melbourne. There is a sensor on the top hose connected to the thermostat which you can adjust.
I have only just completed this installation so I now need to roadtest it under load.
Another option would have been to fit a thermostatically controlled fan on the radiator, there is plenty of room. One advantage of the pump, is that it is wired to continuosly run after the engine is shut down until the temperature reaches your setpoint. Engine temperature rises quite a bit after stopping, which is a good reason to leave your engine idle for a few minutes if you stop at rest areas after travelling at highway speeds.
When I have fully load tested results with the EWP I will post them if anyone is interested.

Cheers,
Bill

Rod N

Most, I repeat MOST manufacturers have done their homework when they release a vehicle on the market. Unless you are asking your vehicle to do something it was never designed for, operating it in extreme ambients, have fitted accessories such as turbos or a bank of lights in front of the radiator that would do a 747 jumbo as landing lights and you have an overheating problem then I would suggest you look for a malfunction such as radiator blockage, thermostat or whatever rather than trying to overcome with an electric water pump. As far as lugging the engine to such low revs that the standard water pump can't do its job try shifting to a lower gear and letting the engine operate in a more appropriate rev range.

Cheers Pop