1985 - 1998 General Motors Cars Heater Core
New Heater Core fits the following vehicles:
New Spectra Premium Aluminum Heater Cores - Inlet Fitting = 3/4", Outlet Fitting = 3/8" - Measures Height = 6 1/2", Width = 7 1/4", Depth = 1"
ISSUE:
Some vehicles may exhibit (repeat) heater core leaks. This may be caused by a chemical reaction called electrolysis. Electrolysis involves an ion exchange between the heater core and engine coolant which can result in a breakdown of the heater core material. This is similar to the operation of a battery.
ACTION:
Check for electrolysis on any vehicle with a heater core failure. If electrolysis is verified, flush the coolant and follow additional steps as required.
SERVICE PROCEDURE:
Electrolysis Inspection:
If there is a condition of a heater core leaking or repeat heater core leak, check for electrolysis using the following procedure:- To check for electrolysis use a DVOM set on DC volts. Place the positive probe of the meter in the engine coolant and the negative probe on the negative battery post.
- Adjust engine throttle to 2000 RPM to properly get coolant flow and true electrolysis voltages.
- If more than .3V is recorded, flush the coolant and recheck.