no radiator cap! how to see if its low on water?

I know this is a Tacoma forum but somebody out there knows the answer so my niece has a 2001 Malibu and it doesn't have a radiator cap, the radiator is completely enclosed under the core support it just has an overflow reservoir.

thing is the other day I saw about a gallon of water on the driveway where she had parked and she said she never dumped anything out so I went to check if the radiator was still full and you CANT.

the overflow tank is half full so I plan to fill it completely and see what happens and if I can find where the water leak is (probably water pump) but how do you know when this thing is full or not full? wait for the engine to overheat or lock up? what a stupid design.

rant over

if anyone has experience with a system like this can you advise on filling checking technics

thank you

 

Drop a mouse in there and watch it swim.

 

im trying to find mouse sized scuba gear on ebay right now

it looked like plain dirty water but it covered from the front wheel to back wheel and had to be at least a gallon of it.

strange thing was the driveway was completely dry, she stopped by to visit for an hour then left and I went outside to see the water there.

this water appeared out of nowhere and I cant seamed to figure out where it came from on a clear sunny day and she said she didn't spill or dump anything out. its really freaky but maybe 6 dogs came take a piss at the same time but the car isn't leaking anything and it only took about a quart to top off the reservoir which is all red dextron fluid so I now know the water was not from the coolant system.

I guess i'll put it in the WTF I dunno category and forget about it.

 

Gotta interject right here on that: The connecting hoses have to be intact and leak free.

A thought on the gallon? of water in the driveway: The air conditioning was on when she drove into the driveway. Nothing to d with the radiator.

 

my first thought too but the a/c is on the opposite side of the car and she didn't have it on since it was around 50 degrees outside that day

 

what rock lobster said. there should be a line on the overflow bottle to show where full is, its usually about half way up the bottle. If you fill the bottle to the top then you'll definitely have a leak as it pushes out the overflow as it expands as it warms up. I bet you'll find that most vehicles now days are set up like that with no cap on the actual radiator, works the same as any other cooling system.

 

It could have been on if she turned on the Windshield Defrost. Has it done it since that first time?

Did some jackass at the Quickie Lube fill up the overflow tank?

 

Brilliant minds think alike.

 

maybe so but I say its a stupid stupid stupid design to have it that way because you cant see if the radiator is full or not or if the water pump is flowing water to see if the thermostat is working. it turns you into a parts changer by necessity because you cant diagnose anything easily.

 

You're beginning to understand modern technology. You must be a quick learn!

 

don't know, she never stops the car long enough to let the cloud of dust catch up to them lol. plus she parks on grass all the time but leaves no dead spots.

its been two weeks just to get her to let me check it and she only came by because now that she "has to use it for a long trip this weekend"

I even thought windshield reservoir tank but it was still full so everything I think of that holds liquid is rulled out

 

you just have to learn to adapt your diagnostic techniques to the technology changes. hell my 97 taco is sophisticated compared to the 70s Chevy trucks I started out with.

 

She keeps a dixie cup in the car?

 

you never really stated what color the liquid was that you seen, that car should be red/orange tinted if it was antifreeze. But if it really lost a gallon of coolant then the overflow wouldn't be half full still like you said it would probably be empty.

 

it was dirty water like leaf stained ditch water, like watered down coffee, it definitely didn't look like coolant at all and checking the reservoir confirmed she had it full of red coolant..

i have no reason to suspect it is the case but ... I been thinking what else could it be but trapped rain water since she doesn't use the car a lot and it sits for weeks at a time, maybe the fender was full of rain water and the trash blocking it from draining moved enough to let it drain out when she stopped in the driveway. its all i can think of because she definitely brought this liquid with her because i was just parked in that spot before she arrived and i was working under my truck and it was bone dry.

she wouldn't lie about dumping something out and she doesn't care what i think about what she does, she is 27 years old and will smoke weed right in front of me so i know she wouldn't be dumping alcohol and lying about it if that's what you are suggesting

 

A few silly questions:
Is the driveway level or not?
Did anyone check the trunk to see if it had caught rain/wash water and drained out that way?
My daughter has a Impala, and it is a pure PITA to work on.

 

driveway is flat and level

trunk is full of crap but dry and not holding water anywhere, plus the water was in between the drivers side tires not at the rear

so is her Malibu, basicly the same car, by the way she got a notice to set up a repair time to come in about the defective ignition recall so your daughters car might be on that list too if its during the year class as the others

 

Don't get your panties in a bunch, nobody suggested she lied about anything. The dixie cup was a joke that went over your head... but it actually is sounding more plausible now.

 

your the only one who got bunched panties, I thought the suggestion actually made sense, joke or not, and I was just giving my reply that in her case its not in question.

you must have a tough time on forums if you are all that sensitive about stuff

 

my 2 cents,
I believe the system has to be "sealed" and pressurized for it to work, especially in transferring liquid back and forth from the overflow to the radiator and back again,,, I've seen the bottle have plenty of water and the radiator be low,,, yes it will overheat.

That being said, looks like something else if she has continued to drive it, otherwise it'd be toasted by now