Slight coolant consumption "normal"?

[byez]

My coolant in the overflow tank of my 08 Tundra 5.7 goes from max to low around every 15,000 km.

I checked the water pump and and cant see any leaks.

Is coolant consumption considered normal?

 

[renegade_987]

Every once and a while that will happen on my f-150. I don't think it is a big deal as long as it is not excessive. When mine does it I just add a little extra and she's good to go!

 

[91344George]

If it is a "sealed" system it should not lose more than a few drops over that time. My guess is you have a slow leak somewhere I would also check the cap to see if the venting valve or seal is defective.

 

[Rand]

so you lose a quart? pint? liter? in 1 year? I'd say thats not normal.

 

[zyxelenator]

Water evaporates over time.

 

[toneydoc]

I would check all the fittings, clamps, hoses, etc. Some expansion and contraction is normal but level should not change too much. Although in the Great White North you are closer to the pole and things could be different than here in the Great South. Check for a small leak

 

[Donald]

You may need to add a dye and check with the proper light and glasses. Small leaks will evaporate so you will never see any drops. Also a pressure test kit could help. Are you checking it at the same temp? If you check it cold and one day its 10F and the next its 40F you might see a difference. Don't use a "leak stop", find the leak and replace/repair what is leaking.

Have you checked the oil for coolant?

 

[Trav]

If its a pressurized overflow no its not normal, there is a small leak somewhere 100%.
If its just a bottle with a flip top cap then yes there can be slight evaporation over long periods.

 

[dparm]

It's a sealed system and in theory should not lose any fluid. In reality, it may lose a very small amount over the course of a year or two.

 

[Trav]

Quote:
In reality, it may lose a very small amount over the course of a year or two.

Maybe but i would guess the difference between cold and hot is anywhere from 0.5-1qt of coolant. That would be quite a bit in 15K.

 

[SHOZ]

I've seen the plastic side tanks on the radiator leak very slowly. Usually when cold.

You can take them out and recrimp them with a vise grips.

 

[antonmnster]

I add about 2-4 oz every 6 months or so.

If it goes up I'll worry.

 

[mechtech2]

Some evaporation is normal.
But your consmption requires more careful observation.

 

[andyd]

Best feature in my BMW is the low coolant level sensor. It is a simple little gizmo in the expansion tank. If the level drops 3", it trips a check light in the overhead display. It is 25 yrs old, so I carry a gallon of premix and some basic tools in the trunk. So far, so good. Ive had several of these cars and have never had an overheat. I think every one of them used a little coolant. All the hose nipples are aluminum, that pits easily. I use Permatex Aviation Forma-gasketon them . It acts as a lube to ease the hose on or off and helps fill in the pits. If a leak gets persistent, I wrap a clean rag or a paper towel around the suspected area. and check it.

 

[Virtuoso]

Originally Posted By: mechtech2
Some evaporation is normal.
But your consmption requires more careful observation.


+1

There is a slow leak somewhere. These are the worst, as they are nearly impossible to spot sometimes.

 

[widman]

No, its not normal for it to drop that far. Next time you have the engine hot, open the hood and look for a slight mist somewhere, especially around hose ends and bends. Look at any hoses. check under the dash around the heater, although you should smell the coolant if it escapes there.

I once had that with a 93 Cherokee. Couldn't find the leak anywhere. Then one day stopped after filling the gas to check under the hood before setting out on a 12 hour trip to the salt flats and there was a tiny stream squirting out 1/2" from the end of a heater hose. A little circumcision and we were on our way.

The other place it can go is the oil from a weak/loose head gasket. Check your oil for milky looks before starting.