supra1970

2015 edge standard aspirated V6 with 18K miles coolant is leaking into the spark plug cavity (external to engine) causing a miss fire of # 5 cylinder. Just started in the last 500 miles only warning was an misfire and check engine light that went on and then reset on it's own. Head casting porosity? dealer had it for 10 days still not repaired. Any one hear about this problem