Hello, I'm a new Member ;)

I have owned my Tundra now for a little over 8 years. Its been the best and most reliable truck I have ever owned. I noticed my check engine light came on yesterday morning, I put my scanner on and the code came back for Insufficient coolant. I just had the radiator replaced about a year ago, so I popped the hood, low and behold the darn antifreeze reservoir was empty. The trucks gages never read that it was getting to hot or overheating of any sorts. I added antifreeze, drove it home which is an hour away from where I work. Checked it when I got home and it seemed like it dropped a little but not enough for me to be able to tell. This morning before leaving to work I checked, and it was completely empty again. The full reservoir is emptying completely with in 8 hours. I see nothing dripping from under the truck any where, Any suggestions that I could get before just running it up to a shop? Thank you in advance guys

 

Hi, my name is Luis, and I like to party!

 

First, welcome from LA (Lower Alabama)! So it emptied overnight while just sitting there? There HAS to be a leak somewhere for that to happen, I would think. You might get a better response by posting this in the Ask the Toyota Mechanic forum.

 

Welcome from Nevada

 

Welcome from Delaware

 

Welcome from Utah! Have you changed your oil recently, to rule out a gasket leak? Next question, when they replaced the radiator did they fill it with new coolant completely? They may have left air in the lines. The resevoir isn't that big so it could easily be sucking that up as the air settles out.

 

Welcome

 

Welcome!

 

welcome from so cal

 

Welcome from SoCal.

 

Welcome from Ohio

 

Welcome from NY.

 

Welcome from NC! You either have air in your coolant system (just burp the system to get the air out), a bad head gasket (does your oil look like a milkshake), or a coolant leak.

 

Welcome from South Carolina!
Another indication of a blown head gasket is often white smoke at the exhaust pipe...If it's a small leak at the head gasket, the motor may only use water when it heats up (crack expands) and the coolant may not actually get into the oil. Vacuum created in the radiator will also pull a little coolant back from the reservoir as needed and as everything cools down. Hoping though that you only have a fixable leak or simply air in the system. But if air, I would be surprise you would just now be seeing a problem after running the new radiator for a year. Best of luck!

 

Welcome and hope you get it resolved…Some great advice on here.

 

The sign of white smoke can be an indicator but isn't an absolute, so it's still possible to have a bad head gasket - sorry. Your shop would probably do a compression test to verify. It sounds like maybe the reservoir/cooling system is working as the reservoir will increase in volume as your engine heats up (coolant expands) and then lose some coolant and the engine cools down and the radiator pulls some coolant back. Maybe you are doing this, but I always dilute 100% antifreeze with water 50/50 or just buy the stuff that comes pre-diluted. I wouldn't worry too much about the color mixing or the coolant color result. (I use the Toyota 50/50 coolant, which is red.) The important point is that you have the correct concentration of antifreeze in your engine. You might want to get an antifreeze level tester just to be sure you have the right concentration for your particular climate.

 

Okay, will do. The coolant I added is prediluted 50/50.