Hi all. I am new to the forum and was hoping you could help me sort out a problem I am having with my 2010 Tundra with 115k miles on it.


About a week ago my heater was blowing cold air and the temperature gauge was acting wacky bouncing around from cold to hot and then finally stabilizing in the middle. I checked the radiator fluid and it was low so I filled up the reservoir and that took care of the heat and temperature gauge problem but by the end of the day the reservoir was empty again. Over the last week I have added a half gallon of fluid but I can't find anywhere that it is leaking out. I read some things that said it could be a leaking head gasket but I checked the oil and the color looks normal and I don't smell any different kind of smell at the exhaust.


Any other ideas what might be wrong? I'd hate to take it to the dealer without first knowing what the issue might be.

 

I would try and get a very good look at the water pump and radiator. You might have a pinhole leak that's letting the fluid out. Sometimes the fluid will evaporate before it starts dripping all over the place. Look for some pink crust/residue in the lower corners of the radiator or around the base of the water pump if you can.

I would guess this would be your issue as a head gasket failure with a vehicle that hasn't over heated and is only 5 years old would be quite uncommon.

 

I realize this is a little late, but if a future searcher is looking for this it may show up. My 2008 5.7L tundra was doing the same thing and it was the water pump. Get under the truck and look up and you will see the red fluid tell-tale sign if it is leaking. The bad news is that is is about $800 or so to fix it.