Running hot loseing antifreeze - 1999 Oldsmobile Alero

Well, Rebecca, we can't have it both ways!
If you are, in fact, losing antifreeze, it will only be a matter of time, (days to weeks) before your engine begins to overheat, and could possibly self-destruct if not quickly fixed.
Now, to be sure it is anti-freeze, dip the very tip of your finger into the liquid and taste it, just a tiny drop. (You or a friend).
If it is antifreeze , it will be really "sweet".
If it is, then it is time to put a radiator pressure tester on the radiator,
pump the tester up to operating pressure, and raise the car up into the air and find that leak.
Will likely take a strong flashlight to see dark areas.
God bless your efforts.

You're losing the antifreeze probably due to a leak. Look under it for a puddle. if no puddle, tighten all hose clamps and have the cap tested, if it's ok, you need to pressure test the cooling system to try to see the leak. If you still can't find it, it may be a head gasket or cracked head.

If yo keep adding then you're obviously losing antifreeze somewhere. If it's not dropping on the ground then I'd say you have a blown head gasket and it's going out the exhaust. If you keep running it hot and it is a blown head gasket, sooner or later you'll warp the head or crack it, then you'll really be outting out the money for a fix.

water pump seal may have gone and blowing water out when engine is hot. or a hose pipe has a pin hole in it run engine and squeezes the pipes around when engine at temp. should not hear any hissing.

Fill the tank with the CORRECT antifreeze up to the fill line (There should be two lines - a "Hot" and a "Cold"). Find out where you are losing your antifreeze - look for a puddle under the vehicle after you fill it. If no puddle, run until the vehicle is warm, shut it down, and look for a puddle.

If your cooling system was empty, you may have to bleed the system after filling the tank. A shop manual for the vehicle should tell you whether you have to bleed the system.

drain the oil an see if it has water in it. if it does that you have a big problem. if not that make sure the freeze plugs are in other than that umm...idk if there is no leaks than it has to be draining into your oil

Hello, if your car has a blown head gasket and exhaust is entering the coolant system, it will continue to run hot until it is repaired. Using pure antifreeze will make it worse. It should be at least 1/2 water. If the coolant reservoir didn't leak you could probably drive a few more miles, but not many, before it overheats again. All that is doing is giving you a little more capacity. If you continue to run the engine hot you are going to do more serious damage to it.
I suggest you have the head gasket replaced. That stuff you put in there seldom works, and if it does work, it's only temporary.

I hope this helps.

It could be the water pump, the air switches from hot to cold because the heater core is the highest point in the cooling system so as you run low on water you lose heat, if the water pump has siezed you are in danger of losing the serpentine belt, so don't wait to get it fixed.

yes, it most likely i think is running very hot
replace the thermostat and try again

gl G

There should be no anti-freeze under the valve covers, just valves, rockers, springs, and oil. If you are getting any antifreeze leaks at the valve cover then you have a cracked head. Since the engine has been pressure tested and has passed, my guess would be that the coolant reservoir is overfilled. Drain it down to the correct level and see if it does it again. If you are getting a strong sweet antifreeze odor when the car is running, you may be in need of a heat core. My PT Cruiser would leak sporadically, and after running a pressure test, it turned out that the 16 pound radiator cap I had on the car was losing pressure at around 8 pounds. so it would only lose antifreeze when it was really hot and/or I was running the AC.