Hi all. Trying to play detective here with a coolant issue on my 2003 Boxster S w/90k miles
Timeline
- Night I arrived to BRBS in 2018, coolant light was flashing after 12 hour drive
- We filled it up, not sure on bleeder valve (assume it is closed)
- On first fun run next day, as soon as I stopped, full coolant dump #1
- We filled up, Alan followed me back to Swiss Inn, went about the day
- Stefan checked it out, we left bleeder valve open, car runs fine for 4 spirited days BRBS, I ship car to Seattle
- Car runs great, I order new coolant cap with 04 on it
- Put new cap on, I close the bleeder valve, go for a spirited drive, as soon as I stop, coolant dump #2
- I fill up, leave bleeder valve open, and (forgive me) drive for the next 2 years with no issues
- Bring in the car for 90k service, ask them to look into the issue. They say:
- Coolant issue appeared to have some air in system. Bled and filled. Pressure tested fine, no overheating or loss of coolant on test drive
- I pick up the car (bleeder valve is closed), spirited drive home, as soon as I stop, coolant dump #3
So my questions are ... before I bring it back to be looked at, has anyone had this and what is my lead?
- Is it the cap? As noted I replaced the cap and this has happened before and after
- Is it the tank? I had replaced the tank in 2012, there have been 0 leaks at any other time, and they said it pressure tested ok
- Indy was thinking it might be a thermostat?
- One message board described the exact situation and said " It turned out that I didn't have the driver's side fan running properly. There is a resistor that according to a local Indy mechanic goes bad somewhat regularly. When it goes bad you lose one of the fan speeds and it can cause the car to dump coolant. That's what happened to mine. They replaced the resistor and the cooling system works fine now." Does that seem feasible?
- Another board said it was the "bleeder valve o-rings." Maybe?
Thanks for your help