Boxster overheating

[Valley Llama]

Brother -in-law borrowed the Boxster for a quick 'spin'. Half of a gas tank later he returns and said it was over heating. He said it dumped a lot of fluid at one point. We talked about watching the gauges, etc. which he said he always ignores. After the fluid dump he drove at least 30 miles with the temp gauge 250 red light flashing and the water sign flashing. After letting it cool down and topping it up and bleeding the air out I find it now runs great until the temp hits the mark to open the thermostat. After it does that it is fine for about 5 minutes then it quickly overheats and dumps a load of coolant out the coolant filler cap. The coolant does not appear to be in the oil at all and nothing is leaking. I suspect some sort of blockage in the system. Any ideas?

[JFP in PA]

Start by shooting your brother in law...……….…………..

[Valley Llama]

Yep - thought of that ... I found were it is leaking, however. The system leaks at the coolant bleeder valve. The wire flip clip just comes off. The coolant flows out of the bleeder valve 'cap'. The device that holds the clip. It is a star shaped sort of thing with 8 screws holding it down. The coolant, when pressurized gushes out from under the star shape cap. I will try to replace it and then see what happens. I'll update as I dance through this thing.

[BYprodriver]

Don't bother if he drove it that hot that long just hire a lawyer to "Fix it".

[Brian in Tucson]

Replace the tank and the thermostat, and keep your fingers crossed. And counsel your sister to divorce the fool ASAP.

Actually if a bad thermostat is the problem (probably is) the bleeder is probably okay. It's just spewing because coolant is boiling and steam is displacing coolant and forcing it back into the tank--is coolant also going out the overflow hose. It would dump in front of the right rear tire.

Good luck

[ddodgen]

your problem sounds chronic but I had an overheat that happened right after I had the starter and the oil air separater replaced. only took a few miles and it topped out. kept putting coolant in it but once it cooled down and topped off it has been fine now for several months. Kept thinking that somehow the coolant lever was lowered when they replaced the parts but don't know how.

[Valley Llama]

I replaced the bleeder valve and the coolant cap - bled the system - crossed my fingers - and it seems to be okay. The oil is a bit darker so I'll change that but it now runs well and I made a quick 10 mile return trip with no challenges. I think the spring 'tune up' will involve changing the pump and thermostat as well as a complete fluid change. If it happens again I will replace the tank...and my brother in law can only look at it now but he can never touch it again. Thanks for the advice and support.