| Auxillary coolant pump leak - fixed | |
Over the past few weeks I had noticed a coolant leak on my tiled garage floor (Ecotile PVC tiles, very good product), which seemed to be getting worse. Having run for a bit by topping the coolant up, the time came for a proper investigation. I thought it likely that the new radiator I fitted earlier this year may be leaking, perhaps from one of the o-rings on the hoses which I hadn't replaced when I changed the radiator, but everything was dry at the front of the coolant system. Closer inspection revealed dripping coolant from the auxillary coolant pump on the left side of the engine bay, down near the left bank exhaust manifold. This small pump is tucked away behind a foil heat shield, together with two solenoid coolant valves:
The heat shield is secured with three 10mm nuts, the lower of which was a right bu**er to get to as access is limited due to the proximity of the left side of the engine:
I managed to get the lower nut off with my Harbour Freight flex-head long reach ratchet with a deep 10mm socket on the end:
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I bought this tool on my last US trip, having seen Christian use one on an LR Time youtube video. It was the only thing I had in my toolkit that worked, and access from below is worse than from above.
With the heat shield removed, the auxillary coolant pump becomes visible, along with the leaking coolant:
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This pump pushes coolant through the heater core, so I learned that my 4.2 supercharged has three coolant pumps - 1. Engine (belt-driven) coolant pump, 2. Supercharger (electric) coolant pump and now 3. Auxillary (electric) coolant pump.
To remove the pump, the inlet and outlet hoses must be removed. These are held in place with wire clips, and some idiot at JLR designed these so the top of the wire clip is facing the chassis rail, rather than inwards towards the engine where access is (relatively) good. One needs to insert a pick or thin screwdriver to pull the wire clip away from the hose end fitting, before releasing the hose. It took me probably two hours of skinned knuckles before I finally had the hoses off and could release the pump.
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This is the pump - it's a BMW part, p/n 6 904 541. I bought a salvage item for £30, a new pump is about £80:
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Once removed, some material could be seen along the pump casing joint:
On splitting the pump, this turned out to be remains of the pump casing sealing o-ring which had been extruded out by the coolant pressure. I put this down to the heat of the left exhaust manifold, which is very close to the pump, probably softening the o-ring material in use.
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I changed the pump for the salvage item and reassembled everything. No leaks were present when the engine was run, proving this failed pump o-ring was the cause of the leak. I hope this write-up helps someone else when trying to find the cause of a coolant leak on their L322. ---------------------------------------
2009 4.2 SC Buckingham Blue
2021 Hilux 2.4
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16th Dec 2024 7:25pm
You mention using floor tiles, have they been down long and did you have to seal the concrete floor before laying them?
