Lets just start over because the cap isn't the problem :(.
There is no dripping whatsoever, no fluid out of the exhaust, and the fans are running perfectly. I installed my own mechanical gauge to ensure the car was in fact overheating. Since then I haven't had my car overheat (two weeks. I haven't added coolant in 600 miles so far.). I check my reservoir every night after work and it's been depleting quickly. After the past 600 miles the reservoir down to the min level and I'm getting worried. I have done a combustion test ( this tests the coolant for carbon deposits / c02 emissions in the coolant. Basically an easy test for a BHG. ) And I also did a pressure test and both didn't come back with any results. After these tests I just went ahead and replaced the thermostat with an OEM thermostat. My car usually runs around 190 degrees and has not exceeded 210 degrees. I noticed something that made me think its a weeping water pump. When I sit at a red light or a few red lights in a row my temp goes up to 205 or 210 degrees but does not exceed this temperature. After I start driving the car cools itself back to 190 degrees.
This sounds like fans but I have tested them and they are perfectly fine. Fans wouldn't explain my coolant loss if the temperature does not exceed 210 degrees the coolant cannot boil out because the temperature is too low.(1.1 bar cap + 50/50 mix). My car runs flawless other than this loss of coolant. Doesn't sound like a BHG when it runs and there were no carbon deposits / c02 gasses in the radiator fluid.
Thanks for reading and I'd appreciate it if anyone could shed light on what I should do / replace next! I have replaced a lot thus far and hope I can pinpoint this soon!
/edit: Also oil is clean and does not contain coolant or water and same goes for the coolant. Coolant is clean and does not contain oil. I have changed my oil within the past week and it was pristine. Also the oil levels are consistent and do not ever decrease. I am very particular on fluid upkeep and keeping an eye on my system.
Tuesday, November 6th, 2012 AT 6:41 AM