I have two cars that regularly sit for longer than that and when I'm ready, I just get in and drive. My '80 Volare runs fine on the gas I last put in about eight years ago.
Changing brake fluid is something that is recommended but almost no one does. It isn't going to be any different from sitting vs. Driving it for the last three years. The reason for replacing it is it loves and absorbs moisture from the air right through the porous rubber hoses and the reservoir cap. Water in the fluid boils at a much lower temperature than brake fluid. When it boils from the normal braking temperatures, that moisture will vaporize and lead to one form of brake fade in the form of a low and mushy pedal. The moisture also promotes corrosion of metal parts.
Antifreeze is alcohol and is always going to be alcohol. It's the additives that become depleted in about two years but that's two years of heating and cooling cycles. Acids form in the coolant from the natural combustion in the engine and leads to corrosion of the metal parts. That chemical reaction is accelerated with higher engine temperatures which yours has not seen recently. Changing the coolant is always a good idea but I wouldn't make that a priority. The goal is to flush the acids out and get new antifreeze with a fresh supply of corrosion inhibitors and water pump lubricant.
The spark plugs didn't deteriorate from sitting. I'd leave them alone, at least for now. If there is some running problem, every part you replace adds another potential variable to the list of things that could have happened. Tugging on the spark plug wires could tear the terminal from the wire's core and lead to a misfire, possibly not right away.
The oil didn't change from sitting in the engine vs. Sitting in the container it came in. The oil in my '93 Dynasty has been changed only once, at 2,500 miles, so I'm driving on 15 year-old oil. It only has 4,100 miles now. The coolant and brake fluid are original, so you can see that age isn't the issue; it's mileage that's important to those items.
Thursday, June 2nd, 2011 AT 11:55 PM