1997 Thunderbird - 4.6 Modular I've read that the 4.6 SOHC is a great motor. I'm sure it is, but given enough time, they all seem to develop an oil leak around the oil filter adapter. It's a casting on the driver's side of the engine block down low in the front. The gasket is a composite with the orange sealing rings built into it. The gasket seals the oil filter input/output and the lower radiator hose output. In time, the rings sealing the oil passages crush down flat and oil leaks around the adapter. Because of the way the engine is mounted in the T-bird, there is virtually no room to access the bolts that hold the adapter on. Even getting to the oil filter is a PITA. The engine was leaking a quart of oil every two days, so it had to be done. I had to go through the wheel well sway bar opening with 20 inches worth of extensions, a ujoint and a 10mm socket. Took a total of 5 hours start to finish. Not one of Ford's better ideas.