oran09

Hey so I own a 2009 Lexus es 350. I recently checked the fluid levels and noticed it was low, the tank was almost empty. I opened the radiator cap and there was still coolant in it. My car never over heats though. The temp gauge on my car has never past the middle between hot and cold. I decided to test it and poured water into the coolant tank as I am gonna going to get it replaced asap. The water level has since not gone down. With about 120 miles put on since then.I suspect it’s the water pump as there is a noise coming from the passenger side of the engine bay. What else could it be if not that.

ESh

It is not necessary the pump. You need to check underneath for leaks.

chuyrobles

The noise could be a worn out bearing in one of the pulleys or the belt. With the belt off, rotate each pulley; they should feel smooth as you rotate. Then check for side to side and fore/aft movement. There should be none, except the PS pulley will sometimes have about 1mm fore/aft play.

As for a possible leak, check the usual places - the hose connections, radiator seams, water pump weep hole, radiator cap, thermostat housing, and coolant reservoir. It is normal for a little loss over time. If it’s been awhile since you last checked, say 50K, you may be alright.

spaceballs

If you're in a rust belt region there's also another common coolant leak location at the head gasket, bascially corrosion from the outside + acidic coolant from the inside (if it's not been changed for a while) all work together to eat through the gasket.
Good news is that this leak won't cause the coolant to mix with the gas or engine oil, bad news is if it's the rear bank that's leaking that's probably an engine out job.

chuyrobles

Is there an update to the disappearing coolant?

oran09

Yeah, I looked around the engine with no engine bay cover and say some pink dried fluid coming from the water pump, the water pump bearing was also worn out. I replaced the pump pulley and the belt all at once at 100k miles. The car runs amazing now, the car definitely got quieter as well.