"O/D off" is overdrive off. There should be a button to activate it. If it does not work then most likely there is an issue with the switch or solenoid on the transmission to actuate it into overdrive.
You need to check the oil pressure immediatly if you have not ever rebuilt the engine. The rattling could indicate extremely worn rod bearings (excessive play in the piston rod), piston slap (form excessively worn piston rings) or a worn main bearing. Does it burn oil excessively? If not then you could probably rule piston slap out. Even the valvtrain could have problems, such as a sticky lifter or extremely worn spring. The key right now is to note oil pressure.
Sunday, July 13th, 2008 AT 11:16 PM