GM Service Manual Online
For 1990-2009 cars only

Object Number: 159495  Size: MH

The engine oil heat exchanger is mounted to the top of the engine block under the intake manifold flange. Oil is pumped to the oil filter, then to the heat exchanger, and on to the rest of the engine. The exchanger provides the following two functions:

    • Engine coolant warms up faster than oil. During cold operation, the coolant warms the oil in order to provide better flow during cold engine operation.
    • During normal operation, the engine coolant cools the oil, which helps increase the oil life and protect the internal engine parts from damage.