So I have had my 2003 VW Jetta for 6 years and never has my car ever hit above the 190 mark. I did lots of logging for timing pull and the log for the water temp was always 100C. Today it was at 108C. I had my drivers side fan go out last week so I replaced it with a Valeo fan off MJM. I removed my upper hose and replaced the fan from the top so coolant came out but very little, I replaced the half gallon that leaked with water. The coolant is still very pink in color. For 2 days it showed normal temps but now it goes from 1 to 2 lines above 190 at a stand still with ac on. I verified the fans run while the ac is on and not one drop of coolant is leaking. I checked the coolant level and made sure there isn't any air in the system. Thermostat was replaced 10K ago and timing belt with water pump was done 25K ago. If I rev the motor alittle at stand still the temp drops back to 190 and slowly climbs again. My thoughts are a sticking thermostat, bad water pump, clogged radiator (but I think unlikely) or the Valeo fan just isn't flowing like the stock fan. What are your thoughts experiences?
Mods are GIAC, 2.5 down pipe, front mount intercooler, 02M swap and a few other bolt ons