XJ Cooling System

Hi folks. I bought a '97 XJ (my first one) a few weeks ago with 110K on it. It has the I6 engine. I'm doing maintenance on it to get everything to where I know what's been done. Right now I'm doing the cooling system. I ran a flush through it for several hours. I just cleaned that out and replaced all of the hoses. Right now it's full of distilled water. I drove it around the block a few times to get it to operating temp. I've let it sit idling several minutes, however, it doesn't seem to get real hot. I only have an idiot light, so I don't know the actual temp. The valve cover isn't that hot. The radiator cap isn't hot enough that it can't be removed. The heater is hot. The upper radiator hose has gotten hot enough that it is uncomfortable to squeeze with my hand. But my real concern is, when I squeeze it, it's real easy to squeeze and I don't feel coolant moving through. I'm hoping that's just because things aren't warm enough and not because my water pump isn't working that well. Should I be worried about the water pump at that mileage on these vehicles? I can see that water has been moving when I remove the radiator cap. As far as the condition of the system goes, there was a little rust in the system, and some white pasty sediment when I flushed it, especially in the lower hose. It's nice and clean now.

The vehicle runs really great, and is fun to drive. Hope I'm not being a worry wart.

sgtpeeper said:

Hi folks. I bought a '97 XJ (my first one) a few weeks ago with 110K on it. It has the I6 engine. I'm doing maintenance on it to get everything to where I know what's been done. Right now I'm doing the cooling system. I ran a flush through it for several hours. I just cleaned that out and replaced all of the hoses. Right now it's full of distilled water. I drove it around the block a few times to get it to operating temp. I've let it sit idling several minutes, however, it doesn't seem to get real hot. I only have an idiot light, so I don't know the actual temp. The valve cover isn't that hot. The radiator cap isn't hot enough that it can't be removed. The heater is hot. The upper radiator hose has gotten hot enough that it is uncomfortable to squeeze with my hand. But my real concern is, when I squeeze it, it's real easy to squeeze and I don't feel coolant moving through. I'm hoping that's just because things aren't warm enough and not because my water pump isn't working that well. Should I be worried about the water pump at that mileage on these vehicles? I can see that water has been moving when I remove the radiator cap. As far as the condition of the system goes, there was a little rust in the system, and some white pasty sediment when I flushed it, especially in the lower hose. It's nice and clean now.

The vehicle runs really great, and is fun to drive. Hope I'm not being a worry wart.

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I'd be very surprised if your water pump wasn't pumping enough coolant. Not impossible but highly unlikely. Buy yourself a cheapo $6 dial thermometer from the hardware store and tape that to the upper hose to help qualify your thermostat function. Or, pull the thermostat and put it in a pan of water on the stove. It should open just before the water reaches a boil.

sgtpeeper said:

I only have an idiot light, so I don't know the actual temp.

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Do yourself a huge favour and either install an aftermarket water temperature gauge or swap in an instrument panel that has all the gauges from another junkyard XJ together with the wiring harness and sending units.
Your XJ deserves a lot better than an idiot light, especially when it concerns the cooling system.

It is also not a good idea to run it only with distilled water, the anti-freezes not only provide anti-corrosion protection but they also lubricate the pump bearings/seals. The aluminum safe coolants immeadiatlely adhere to the alumium in the rad and provide coverage.
The way I normally fill it is to drain the coolant out, dump a gallon of pure anti-freeze and then a gallon of distilled water in. Then I take remaining gallon of pure antifreeze and dump half of it in the empy antifreeze container and fill both half full bottle with the remaining gallon of distilled water, end up with two coolant bottles of 50/50 mix, though after reading some articles I think I'm going to be leaning towards a 60/40 mix of anti-freeze/distilled water to get more anti-corrosion protection. I also drain and clean the overflow bottle and fill it half way with a 50/50 mix. Then top the rad off while it's running and allow as much air to escape as possible before I cap it.

Loosen the belt and see if you can physically move the water pump pully with your hands.ANY movement other than normal circular movement might indicate that the bearings inside the pump are shot..