I've been noticing my coolant level seems to be going down. The last two times I had it in the shop they reported a low level and refilled it. Followed by today I noticed it's near empty on the reservoir. It's disappearing and I have no idea where it's going. No drip marks underneath anywhere on the driveway or the car. No pink sludge on the bottom of the radiator. No pinkish hue or any indication it's getting into the engine oil on the dip stick... I'm at a loss here, any ideas?

 

Could be the water pump and it is slowly coming out the weep hole. Remove the oil filter cover under the car and look up in there with a flashlight for pink, crusty crystals. The plastic panels under the car would catch most of it, but will crystalize. If you have 75k miles or more, I would strongly suggest it is the water pump.

I thought I was in the GS350 forum thread, but still stand by having the water pump inspected. There is a skid plate on the GX you take off and look for the pink crystals

 

That's at least a suggestion. I'll get up under there with a flashlight, I have no idea where that outlet would be.

 

My 07 was leaking at the water pump. When I was replacing the water timing belt I did the pump also. It was leaking and drying up and not even hitting the ground. I could not see it without taking it apart.

Seth

 

Like the others have said, take the front skid plate off, and look up on the drivers side of the block. On bad leaks, there will be a pink crusty trail down the side of the block, other times you can't really see it without taking it apart. But if the radiator isn't leaking, my money is on the water pump.

 

Mine was very solid at the high level mark for the first 50K miles. Then slowly started going down. By 100K miles, I could barely see the fluid in the reservoir. Replaced the water pump with the timing belt at 100K point. Now the level is pretty solid for the past 5K miles.

 

Quite unlikely to be the case but I had a similar problem with a Taco and it turned out to be a crack in the engine block. A quick smell around the tailpipe confirmed it was burning it. But you have to work that engine very hard for that (like say all coolant drains from a puncture but temp gauge doesn't move and it's -25