Hello everybody.

After 3 days of not driving my 2006 Acura TL auto, I noticed that engine coolant reservoir is empty. Is this normal?

Last time I took my car to mechanic, he said he didn't see any leaks.

Thanks!

 

No!

1) When the engine is cold, open the radiator cap and check the coolant level. Is there coolant in the radiator?
If yes, make sure the coolant level is filled to just below the radiator cap neck. Use Honda pre-mixed coolant (from a Honda or Acura dealer) to top off.
If no, i.e. you can see dry radiator plates, you may have a problem and should take the car to the mechanic.

2) If the radiator has fluid, close the cap and then look at the hose between the cap and the coolant reservoir-- any signs of greenish or bluish liquid?
If yes, there is an adjacent leak you'll have to keep an eye on for a few days to determine if repair is necessary. Also check the reservoir cap for cracking and replace if necessary.
Fill the reservoir to the top line, then drive the car until warm and check for leaks.
Then drive and check the level for the next several days to make sure everything is OK.

If everything appears normal, the low coolant was probably due to normal consumption/evaporation.

Welcome to AZ.

 

check you oil level, is it high?

 

Definitely check the level of the radiator itself like these guys have suggested. I notice that the level in my reservoir changes based on if I use heat or cooling A/C. I think the system has to remove coolant from the reservoir to place coolant inside of the heater core, and when it is off, it is placed back into the reservoir after some time when the car closes the heater valve.

 

I don't think so. The reservoir is for normal operation of the car. When the car is hot it's normal for the coolant to "expand" and some will move to the res. When the car cools, a vacuum is formed as the coolant "shrinks" and coolant is drawn from the res. "Expand" and "shrink" are used loosely here. If you are seeing the res dip when the hear is turned on then you have air somewhere in the system that isn't getting purged.

OP - It's not normal. It's exiting somewhere. Hopefully to the outside and not into the engine. As others said, do yourself a favor and use the genuine Honda/Acura pre-mix to top off and see what happens.

 

Make sure it's not in the oil, add some more coolant or distilled water to top off.