I always used 10w30 or 10w40 Castrol Oil.
The 1998 Ford Expedition Owner Guide shows ( 5W-30 )
How do you change gear oil in a 1998 expedition?"
On a 1997 or 1998 Ford Expedition ( 5W-30 ) * with engine oil filter change , 5.7 liters / 6.0 U.S. quarts
4.6 and 5.4 are using 5W30
The 1998 Ford Expedition owners manual shows ( 5W-30 )
The motor oil, in your 1998 Ford expedition, should be put in the oil fill tube. The oil fill tube should have a That labels it as the oil fill tube.
According to the 1998 Ford Expedition Owner Guide ( 5W-30 ) * with engine oil filter change , 6.0 U.S. quarts of 5W-30 engine oil for the 4.6 and 5.4 litre V8 engines
A 1998 Ford Expedition with the V8 4.6L engine requires 6.0 quarts of oil.
( 6 quarts ) with engine oil filter change ( according to the 1998 Ford Expedition Owner Guide )
( 6 quarts ) with engine oil filter change , according to the Owner Guide
According to the 1998 Ford Expedition Owner Guide ( 5W-30 ) * with engine oil filter change , 6.0 U.S. quarts of 5W-30 engine oil
On my 1998 Ford Expedition XLT. The oil filter was located on the drivers side behind or near the front bumper.