Cooling system issue

[tonyfromjersey]

This just started this past week. The car starts up fine, and as it starts running okay, but as I drive, the temperature climbs directly into the "red" zone. It stays there a few minutes, then abruptly falls into the normal range. It stays there for the rest of the drive unless I get stuck in traffic, in which case it starts to climb but stays safely in the normal range. Just out of curiosity, I put the heat on while the temp gauge was in the "red zone" and it was blowing cold air, but as the car ran for a while it blew hot air as usual. The car has showed no other signs of overheating nor is there any smell of anti-freeze. The final issue is that the fan seems to run forever after I turn off the car and drains the battery.

Any ideas?

Thanks,

Tony

77 Spider 1800
05 BMW 325xi
1963 Boeing KC135R

[rlux4]

While it's in the red zone get out and check your bottom radiator hose, if it's not HOT the thermostat is sticking closed, perhaps popping open eventually. You can do a visual check of the thermostat by putting it in water and heating it. It should start to open around 100° and be fully open around 190°.
Also, when it's operating in the normal range, run your hand along the bottom part of the radiator left to right and see if you have any cold spots, indicating plugged tubes.
Good luck,
Ron

[So Cal Mark]

erratic heating/cooling usually means air in the system

[kristoj]

Definitely want to begin by beeding the system and go from there.

[mbouse]

http://webpages.charter.net/mbouse/Blee ... System.pdf

Seems to be a popular theme this week.

[mdrburchette]

If it is air in the system, I'd be wanting to find out why. You should consider pressure testing the system once you've purged the air.

[ga.spyder]

Tony ,I had the same symptoms ,scroll down to ''cooling system problem''.I did not have air in my systembut my guage was reading hot then would snap back to normal(not gradually fall).I disconnected the black overheat sensor(not the red guage sensor!),cleaned all grounds,and put a new end on my guage sensor.All is back to normal,I did buy a temp guage on ebay ,but installed it after the problem was solved.
good luck ,Craig

[racydave]

No heat from heater indicates possible air.

[tonyfromjersey]

Finally getting to the car today, going to replace the thermostat as I saw some leakage and the bottom hose was cold, then I will try the bleeding the system procedure outlined above. It's too nice outside to leave the convertible in the garage.

[tonyfromjersey]

Thanks again for all the advice guys, I'm back up and running cool. The only thing I missed was the "clean the garage floor" procedure after I missed the drain pan and dropped half a gallon of old anti-freeze on the floor . Otherwise not too difficult of a job.

Tony

[So Cal Mark]

congrats, thanks for the update

[rlux4]

Cool! Cool.
Ron