Over heating issue
Have 2007 C70 with 150,000 miles. Runs great but has been over heating for the last month. Yes, it has been hot here, hitting 108 down in Fresno. I live in Coarsegold CA. , elevation 2500 ft., usually about 10 degrees cooler than in Fresno. During drive down into town ,no problems. Coming back home no problem until I pull into driveway and shut engine off. Then the coolant starts boiling back into the coolant bottle causing pressure to build up, coolant overflows and has ruptured one coolant tank already. Have taken vehicle to both European specialty shop and the Fresno Volvo dealer with no found root cause. Replaced coolant tank and cap, thermostat, ETC module. Run all the ECM tests with no fault codes found. The fan assy with sensor was replaced, same problem. All electrical tests and circuit tests are OK. Still, , it overheats when coming up hill back home. Any ideas or similar concerns. Thanks.