Daughter's 02 Camry 4 cly has a slow antifreeze leak. Takes 200 miles or so and reservoir goes to Low level.
Have looked extensively for fluid on ground, in engine compartment, on engine components but have found no evidence of leaking.
No white smoke at start up and no obvious oil contamination.
Carpet not wet anywhere under dash.
Radiator cap hold pressure when tested - no decrease over 10 min.
Radiator pressure test dropped just under 1 psi over 10 min.

Any advice on other checks I can make to identify the problem? Thinking the start of a head gasket problem. I'm not familiar with how to check for combustion gases or for antifreeze in the oil. Any advice appreciated.

 

Check for pinkish residue (if you are running the Japanese style coolant which is redish) around the water pump.
If there is no signs of this pinkish stuff, almost looks like red corrosion, do a cylinder pressure test to rule out a blown head gasket.
Has the car overheated? Just overheating one time can blow the head gasket and the result can be slow to show itself.

 

Not using the pink coolant - but no sign around water pump of any residue or discoloration.Bought car used about 2.5 years ago - so no history beyond that on overheating. Going to check combustion gases then will do pressure test.

 

Can anyone tell me the location of the weep hole on the 02 Camry water pump? Best/easiest to see from underneath the vehicle?

 

I had a leak on my 1995 Toyota Camry 180k and I kept adding ( monitoring the increases over time) until I could see the leak. It was a very slight crack between the upper hose connection and radiator. This car was driven locally so if something leaked or burst it was always a few miles away and towable. I did not want to spend the money to have someone do it since I would be out hundreds and they probably would not find it. I has to use a magnifying glass to see it.