The 93 Ford 3.8 engine utilizes Torque-to-Yield head bolts. If you didn't replace the head bolts and torque/turn them correctly, you've most likely caused the same problem over you were trying to fix. Plus, if you don't do the sequence properly, you'll have issues again. Here is the installation process for the heads:
- Clean the cylinder head bolt hole threads with a tap. Lightly oil all bolt and stud bolt threads before installation except those entering coolant jackets.
- Position new head gasket(s) on the cylinder block using the dowels for alignment.
- Position the cylinder head(s) on the block and install the new bolts hand tight.
- Torque the head bolts in the proper sequence as follows:
- 37 ft. lbs. (50 Nm)
- 45 ft. lbs. (60 Nm)
- 52 ft. lbs. (70 Nm)
- 59 ft. lbs. (80 Nm)
- Loosen each bolt one at a time in sequence 2-3 turns, then torque to 11-18 ft. lbs. (15-25 Nm)
- Rotate each bolt in sequence an additional 90 degrees.
Here is an image of what the torque sequence looks like on the head:
(Source: Chilton Auto Repair Manual 1993-1997 Pg 13-34)