Coolant lost at times?

05 PreRunner 2WD V6 Automatic. I have noticed the coolant level dropping. But it doesn't seem to be doing it all time. Have not found any signs of leaks around engine compartment or on the ground. The first time I notìce this, I was cĺeaning out the glovebox and found that it was damp. But after clearing out glovebox, and placing a papertowel inside, haven't seen any signs of the leak. My fìrst thought is the heater coil might be the issue.
Any thoughts?

 

Have a mechanic do a pressure test to see if your water pump is bad ....

It's a starting place...

 

My 05 did this too. Pressure tested. Never could find out where it went.

 

Thanks Yoda & Jokker! I will definitely start with the pressure test.

 

I replaced my water pump, no leaks, but it does need to be topped off once in a while

 

Thanks "thewarriordinghy"! I haven't seen signs of a leak in the water pump area. But, I will not rule it out.

 

Different engine, but I usually have to top off about every 9 months or so. Coolant will slowly evaporate through the vent in the overflow. That said, when my water pump went bad at ~20,000 miles, it only had a slow trickle from the weep hole. Never reached the ground but it left a pink trail of crust down the front of the engine block.

 

I will take another look to see any signs. Thanks ecoterragaia

 

No problem

 

Pressure test and do that thoroughly. You have 05 Truck and those are "known" to have head gasket problem.once you replace it it will work but factory HG had some issue.

 

BlueT, would I be able to see any signs of a bad head gasket? Like foaming on the oil dipstix. I'm not losing coolant continuously. Thanks for shedding some more light on this problem!

 

Do search on the 2gen forum for headgasket issue, there are a lot of different things that may show up, most is now written up in various threads.
If you catch headgasket right at the beginning, all you need is new headgasket, than will need new or machined heads, and lastly if you completely ignore a new engine.
So you need to find a leak.

 

Great BlueT. Thanks for pointing me in that direction.