Coolant Pump

Information Only- There are two pumps within the cooling system:- One electrical coolant pump One mechanical coolant pump

Coolant Pump

How to test the pump

The electric pump operates when the engine temp is v-high, but the engine is turned off. The fans and pump use the same switch (next to the thermostat). To test the pump run the engine until the fans come on, turn off the engine and listen to the pump (it's quiet, so go around to the front of the car).

Check the fuse

The pump has its own fuse, so if the fans operate but the pump does not, check the fuse first! It's located under the dash-cover (remove the two screws and lift off). It is fuse no. 4 in the 'C' fuse box

Locating the pump

The coolant pump is located next to the left hand headlight pod (when sat in the car). It is a little electric pump with two wires and two hoses attached.

Sourcing a new pump

During my research Ashaman found a site which showed a very similar pump, which had been used in the past to replace a Mercedes coolant pump, which is very similar to the Lotus pump.

http://www.autoperformanceengineering.com/html/jabsco.html#C030P5

This pump is 12 volt and features a magnetic drive - this means that there is no way for water to ever get into the electrics. It also means that if a foreign body got into the impeller and jammed it, the motor should not burn out.

I purchased my pump in the UK from: http://www.southernmarine.co.uk/index.htm (look under JABSCO CIRCULATION PUMPS).

59500-0012 Jabsco 59500 circulation pump

It cost me £95 inc VAT, compared to the Lotus part at £195 inc VAT.

When the pump arrived it turned out to be EXACTLY the same shape and size as the original. Even the wire colouring is the same. Only difference seems to be that they recommend a 2.5amp fuse rather than the 5amp recommended for the original pump.

How to fit

1. Make sure that the coolant is COLD!
2. No need to drain coolant, not much spills as the pump is at the top of the system.
3. Loosen the water pipes attached to the pump.
4. Remove the 8mm bolt holding the pump in place.
5. Keep the piece of rubber that is wrapped around the pump for fitting the new one.
6. Get the new pump ready, then quickly pull the water hoses off the old pump and place onto the new one.
7. Fit new pump in the mount with the rubber etc.
8. Cut the power lead for the old pump and use an electrical joining block to connect the wires to the old connector (or use a new connector).