S10 Blazer

Coolant Leak From Heater Core on Chevrolet S10 Blazer

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: 118,937 (53,000–200,000)
5 model years affected: 1990, 1991, 1992, 1993, more1994
15 people reported this problem
Viewing 1 - 7 of 7 comments
heater core started leaking on right front carpet; tied off hoses,plugged one with wooden dowl and clamp.have been driving w/o heater....during tolerable winter conditions~~~~~~~`
Replaced the heater core and installed a ground wire from the heater core to the chassis ground. Blazer now has 247000 miles and haven't replaced the heater core or the radiator since. Electrolysis is a terrible thing.
Heater core went out and antifreeze leaked in the passenger side floor board. A new heater core had to be installed