GF drove the 9-5 without cap on coolant tank !

[01stage295aero]

so the girlfriend drove my car around tonight with the cap to the overflow tank off..... said the car did not over heat or throw any lights... when she pulled into the driveway and shut the car off coolant puked out a little... is it possible to drive it with no cap on the overflow tank ?!

[bornfromjets03]

I'd assume so.. I wouldn't go doing it for weight reduction though.

All I can think of is that coolant flow wouldn't be as good due to the fact that the system wouldn't be able to pressurize correctly

[bob3000]

I drove mine for about 20 miles with the cap off so the system would pressurize when my heater bypass valve failed .

No big deal and no harm will be done.

[01stage295aero]

cool.. dodged the bullet on that one replaced the thermostat and did a flush when i got pulled away from the car, on the phone for 20 mins.. meanwhile she shut the hood and thought it was good See this is the bad thing about her being down with a bad turbo hahaha luckily it was in the low 60's last night not 95 like earlier in the day