The heater core under the right side of the dashboard may leak engine coolant which can puddle on the passenger front floor. The loss of coolant may cause an engine overheating condition. Our technicians tell us that removal of the dash board is necessary to replace the heater on these vehicles.
Coolant Leak From Heater Core on GMC S15
Average mileage: (–)
1 model year affected: 1990
1 person reported this problem