yesterday i checked fluids in my hatch with a d16z6. the radiator seemed to be one inch from the top full. looked at the overflow tank, it was basically empty. put 50/50 mix in the overflow tank until it was above minimum level. checked it todayand it was below minimum, basically empty.

yesterday when i filled the overflow tank it was much warmer, today its 20 degrees cooler. i also ran my car for a while last night. is this settling in the overflow tank normal? my car never goes above 1/2 on the temp gauge also.



(also anyone with eg stock fenders in Seattle area message me)

 

Not for a days worth of driving.

 

should i fill it back up again and see what happens? ill check for any leaks in the overflow tank as well. what other possibilities can make this happen?

 

You can try the experiment a couple more times to make sure. Make sure there is no air in the system. Otherwise I'd start suspecting the headgasket.

 

Ya I would burp the system and make sure theres no air in the system... OEM cap? You could also use a coolant system tester and make sure there are no leaks

 

leaks under the car? white smoke out the tailpipe?

if no to those questions......

feel the passenger side floor well, is it wet?
A bad heater car will steal alot of antifreeze....

 

When the coolant level is low, you should top off BOTH the radiator and reservoir with coolant. Bleeding the cooling system may also be a good idea.

 

There could be multiple issues causing you to loose coolant. Start with the cheap/obvious solutions:

Like others have mentioned - make sure you have no air in your system by bleeding it. There should be a small bleeder located either by the thermostat or by the upper radiator hose connection to the head. I usually fill my cars by back filling it through the lower hose connection at the thermostat.

Next, take off your radiator cap (when it is cool), there is a silver spring loaded button on the bottom of your cap. If it just hangs, that means your cap is bad. Also check the rubber gasket on the cap as well as where the radiator cap sits into the radiator, sometimes that part has erroded away causing coolant to flow into your reservoir and not flow back.You can also get your radiator system pressure tested, it is a very simple process and should take no more than 5 minutes at a mechanics shop. They can also test your cap with the same tool.

More advanced checks: After running your car up to its operating temperature (enough to where your thermostat opens and your fan kicks on/off a few times), run your hand over the entier radiator, feel for cool spots. If you find very noticeable cool spots, it means your radiator is partially plugged. Cheapest fix will be to replace the radiator (and cap).

I'm assuming your fan and thermostat is working properly because you said it doesn't operate above 1/2 on your temperature gauge.

GL
-USDM1

 

Look for white spots around the engine bay. If you have a leak and the coolant dries it leaves a white residue where the coolant was and has dried.

If you can, raise the front end of your car up a little bit, jack stands or ramps will be great. If you don't have those items then just prop your front end on a curb. Turn your heater on high heat and full blast to speed up the bleeding process. Grab a funnel, stick it in the hole for the radiator and pour the 50/50 mix in till its about half way up the funnel. As the air comes out the 50/50 mix in the funnel will recede, leaving you with an airless system.

 

you wanna fill the radiator first then fill the overflow tank.
do you have any other symptoms that you notice? idle, etc?