This appears few weeks ago. Cannot find the source of leak. Wipe it clean. Reappear again. No sign of overheating. Coolant level drop not observerable. Anyone experiences a similar case?

 

Looks like spray from a really small pinhole somewhere. Get her really hot and then have a look while the engine is still running.

 

Thanks for your recommendation. So, I should include the reservoir inside the problem solving. Will find chance to get it warmed up. Very light driving recently with regular gas priced over two bucks Canadian a liter. I always go with 91 with my eyes closed when looking at the pump.

 

Check the Whole Fan shroud assembly

 

your radiator is likely leaking from the top seam, which is common after 20+ years of age.

 

The radiator among with the upper/lower rad hoses, accessory belt, tensioner were replaced on the timing belt job about a year ago. The new radiator is Denso branded. I took out the intake duct and the radiator is very clean. Only the reservior has pink dots...

 

i would do a pressure test on the cooling system to determine where the leak is coming from

 

Something to keep in mind the fans may be blowing coolant masking where the leak is. Sometimes small leaks will not reveal themselves with a pressure test. Best bet is to rinse it off with brakekleen and/or water combo then when dry sit there and watch to see what happens. Pink red toyota coolant is very corrosive and will eat small pinholes in the radiator and such.

 

I have posted a TON about coolant loss / leaks. Mine was first a leaky radiator, then non OEM clamps, which I had to keep tightening. Then another radiator started leaking and this time I used OEM clamps. Now I am still losing a tiny bit. I am told its a leaky water pump. I am about to do a timing belt job and replace the water pump in the process.

 

My 17 year old radiator cracked and caused a Blown Head Gasket
If your radiator is very old and looks like it is flaking out, maybe just replace the whole cooling system (radiator, cap, hoses, ...) instead of trying to fix it?

 

Thanks everyone's experience and sharing. My Denso radiator, upper / lower hoses, water pump, thermostat, gaskets were replaced one year ago. Pink coolant was filled after.

From you guys recommendation, I've observed for further leaks / bubbleing when engine up to temperature. As for now, I cleaned the reservoir really well. Will observe further. No coolant observable so far