Q. Is it normal for a customer to lose up to a quart of oil every 2,000 miles?
A. Surprisingly, if your customer is driving a 1999-2002 GM truck with the 4.8L V8 (also known as the Vortec 4800), the answer is "yes." General Motors says oil consumption of this magnitude under normal operating conditions is perfectly normal for these engines. However, a new fixed orifice PCV valve (p/n 12572717) is now available.
GM offers these suggestions:
Verify that the oil consumption is not the result of an oil leak or any other engine concern.
Perform an oil consumption test. GM says that at least 4,000 miles should be driven before the oil consumption rate can be established.
Remove the PCV valve and inspect the hose going to the intake manifold for signs of excessive oil.
If excessive oil is found in the hose, replace the PCV with a new style valve.
Figure 1 (above right) shows the difference between the older style spring and plunger type and the revised new style fixed orifice valve. The fixed orifice PCV valve has no moving parts and will not rattle when shaken. If a new style valve has already been fitted, oil consumption may be due to other causes.
Q. How can I determine which of the Toyota 1.8L engines I