Love all this Raoult's Law, Graham's Law, takes me back to high schoool chemistry.

I checked my coolant today and it was below the low line when cold. Bringing it in this week

Mine is also below low when cold. I haven't checked it with the engine warmed up its been in the garage for a few days. I've got about 17,000 KMs on it, 3 oil changes in already.

LOL, bringing the car in dealer for a coolant check? You guy must be loving the wait at the dealer. Some coolant top off is normal for any car; if the car actually has problem then there should be coolant smell or oil contamination. Enjoy your car instead of freaking out about every little details....

??

I wait to take my car in when I have 3-4 things to do at once since I hate driving anything but my BRZ.

-WQC-039 recall
-My epic windshield issue
-fuel pump
-coolant

Enjoy your car instead of making assumptions about other people. :thumbsup:

I think its the other way around... fluid under pressure takes longer to heat up than fluid not under pressure. Hence the "boiling" once you have opened the pressurized system. I could be wrong, but thats my take on it.

I smell antifreeze burning after mine has been running for about 30 minutes, dealer couldnt find anything, so I'm going to take my blacklight to it. Its not a normal black light, its a mercury filled bulb that puts out 4000 microwatts/cm squared... its pretty damn bright... and I have a uv filter to it makes a high intensity blacklight and antifreeze will glow neon with this light. If I find a leak, I'll snap a pic and show you where I found mine.

Well technically speaking, you don't need to heat up a container to make the water inside boil, you can just drop the pressure.

Grab a box of pasta, it should say to boil it longer if you're in a high altitude (low pressure) area.


@ahausheer's rationale seems right on the money.

To go back to my last post regarding the issue and the coolant being topped off. Scientifically speaking, it should take MORE time to get to operating temp but at the same time, the car should stay warmer LONGER after getting to operating temp and turning the car off.

I haven't really noticed a truly longer warm up time, maybe by about 10-15 seconds. On the other hand, I do notice the car staying warm longer after I let it sit. I used to come back to the car 2 hours later and have to wait for it to reach the 6oclock position on the thermostat. Now I can just get in and go it seems.

Edit: The dealership insisted on running a pressure test for me. No leaks anywhere.

Yea, thats what I said... lol.

If I'm not mistaken, shouldn't it "burp" back into the reservoir. I think thats where the overflow is... Again, I could be wrong, I'm not much of a hvac guy. I know I had an old school chevy, and it overflowed back into reservoir and then if the reservoir filled up it just spewed over on the ground.

I just derped hard.

Yeah if I got this right, you're saying the specific heat (energy required to raise the temp +1º) increases with increasing pressure? If so that's completely right.

Thing is with a fluid like antifreeze (50/50 mix), the heat capacity would be so high and the differences in pressure (open vs closed radiator cap) would be so low that they may not be note worthy.

95% mad, 5% scientist.



That's pretty much how I imagined it. I remember on my last car the coolant expansion tank had a lid you could open with a hose on the top. One end transferred coolant and the other was open to the atmosphere. I literally know nothing about automotive cooling and I'd rather not take "educated" guesses at where exactly this system becomes closed if ever.

Thats exactly what I was saying... lol.

The system is closed in the radiator cap. The spring in the cap has a certain amount of pressure. When the water pump is spinning it creates a vacuum/suction to pump through the block and return to radiator where heat dissipates. Should you become low, the pressure decreases, and pulls in fluid from the burp tank (reservoir).

Again, I'm not a mechanic, nor hvac guy, I know friends who are, and my college experience was only 1 semester of automotive engineering.

But I think we got a pretty good handle on it, :party0030: Lets go build a car now... lol

Damn just saw this, didn't follow up on the thread. I'm going to call Scion & ask, definitely going to get my $ back for the coolant then. Thanks! :bonk:

Need to go back anyways because one of my rear shocks is leaking. Should be covered under warranty tho. Yes it was Longo, don't usually have problems but my ace service tech (Meng) was out that day.

A car shouldnt use coolant. The cooling system is a closed system, so if there is any disappearing, you either have a coolant leak or the car is burning coolant. Either way its a warranty issue. The dealer should fix it.

Are you checking the overflow tank? because that can go up and down. its not a solid indicator of how much coolant is in your radiator/cooling system. The overflow tank is just a place to go when the fluid is hot and expands beyond what the system can hold. It could be empty and it doesn't necessarily mean you're low on coolant.

Lots of inaccurate info here...
 

Guys, you are all not entirely correct. Let's look at the facts that I DO know:

Fact #1:
The boiling point of a liquid will change based on the pressure it is exposed to. Eg: Water at standard atmospheric pressure boils at 100 deg C or 212 deg F. If the water was taken up the top of say, Mount Everest, it would boil at a significantly lower temperature.

Fact #2:
Liquids DO expand and contract due to temperature. I work in this industry and make a good living out of it so I know this as fact. You'd be surprised at how many 'engineers' conveniently forget thermal expansion for fluids happen. Liquids can also compress (contrary to popular belief that they don't).

Okay, now extrapolating to a car (key word: extrapolate - these are not 'confirmed' facts by me), the cooling loop that you can visually see on the car engine bay is the overflow / reservoir which is usually there to allow for thermal expansion and contraction much like in my industry how we have thermal expansion tanks that can take in additional fluid or squeeze it back into a system. This means that depending on when you check you car, the level will most likely vary.

Also keep in mind that ALL fluids even when exposed to ambient temperatures CAN evaporate (even if the temperature never actually hits the boiling point). There is an equilibrium between the air and the fluid and the fluid vapour pressure allowable in the air. If you are in a really dry room, you don't have to heat the water much to actually get it to evaporate (albeit it may take a while). The coolant loop in your car is not truly "sealed" and thus can evaporate to atmosphere quite readily (again, it may take forever but it IS possible). When I say truly sealed, I mean something like your refridgerant in your AC or fridge. THAT is truly sealed with no way of it getting out short of a physical leak.

The moral of the story? If you are that worried - look out for blue patches in your engine bay and under your car. If that stuff is truly leaking and/or evaporating off a surface, you will see signs of blue crust. Keep a log of the level, air temperature, coolant temperature (if you can) in order to truly diagnose whether you are leaking or simply in transition between expansion and contraction.

A leak is a leak and you will physically see something (puddle, crust, etc.).

Let's use our heads and get facts ladies and gents. Not some heresay.