Slow Water Loss

2000 Jeep Granda Cherokee, 112K Miles.

Jeep losses water (2 quarts) over a 2-3 week period. Coolant reservoir does NOT draw down. Replaced filler cap and seemed to work for a short period of time. Occasionally, it does draw down but, have not found any sign of water loss. I must fill radiator directly for the system to work properly, otherwise it overheats.

Thoughts?

2000 Jeep Granda Cherokee, 112K Miles.

Jeep losses water (2 quarts) over a 2-3 week period. Coolant reservoir does NOT draw down. Replaced filler cap and seemed to work for a short period of time. Occasionally, it does draw down but, have not found any sign of water loss. I must fill radiator directly for the system to work properly, otherwise it overheats.

Thoughts?
First - Welcome to the forum.

Could be a couple of things, but I would check (or replace) the hose that goes between the radiator filler neck and the reservoir tank. It may have a hole in it or otherwise be "leaky" or blocked. That means also check for a clogged hose or loose clamps on the hose at each end. Also check for any "dirt" around the filler neck (since it seemed to work for a short time).

I say this because the radiator should draw coolant (by vacuum) from the reservoir as the system cools.

Please let us know what you find.

Take Care,

Don't they make an anti freeze or an additive now with the UV leak detector stuff in it like for A/C systems?

Don't they make an anti freeze or an additive now with the UV leak detector stuff in it like for A/C systems?

You can get flourecent dye additives to use with a black light. Check with Napa, or ask your local dealer if they can sell you a bottle.

Coolant leaks also typically leave a whitish scunge trail if it has been going on for very long. Look for clamp seepage, water pump seal etc.

Internal leaks into the crankcase can leave a chocolate milkshake scum under the oil fill cap and elsewhere.

It does sound like you are pulling in air if it isnt drawing coolant from the reservior. You could also have the wrong cap.

Coolant also leeks out of the water pump. I have a '96 i just recently replaced that because the gasket was bad. You can check it, on the top there is a "weep hole" and if coolant is coming out of that then the gasket is bad. Usually it drains off of the bottom of the engine, right in the middle.

Coolant also leeks out of the water pump. I have a '96 i just recently replaced that because the gasket was bad. You can check it, on the top there is a "weep hole" and if coolant is coming out of that then the gasket is bad. Usually it drains off of the bottom of the engine, right in the middle.

Turns out I actually had two problems. First, the radiator cap was not seated properly and thus it did not always draw a vacuum. Second, after running in park there was no leak detected. However, after driving around I noticed a small leak in the area of the water pump. Replaced the pump and fixed the cap now all is well. Thanks.