Starting a car that sat for four years

Question:

I bought a 1979 Corvette in February 2007 with intentions to replace the existing L82 engine and automatic transmission. Now I see I will have to put off the replacement for another year or more. So, in the meantime, I want to drive this car instead of having to wait another year. The problem, however, is that this car was last driven in 1995, and has not been started or moved in the past four years. However, it has been kept under a shelter and covered all that time.

I recall having read an article on starting an engine that has been sitting for many years, but cannot find it.

As best I remember, this article mentioned a stepped process of changing the oil several times, and adding transmission fluid to the engine oil to soften old seals and gaskets. Any help or suggestions on trying to get some use out of this old engine and transmission would be greatly appreciated.

Answer:

The first thing you should do is determine whether or not the engine is stuck. Using a socket and large ratchet or breaker bar, try to rotate the engine by hand using the crankshaft pulley bolt. As an alternative, you can remove the flywheel inspection cover to try turning the engine via the flywheel with a flywheel tool. Make sure the transmission is in neutral if you try this technique.

If the engine is stuck, you can try to free it by removing the spark plugs and injecting Marvel Mystery Oil or another high-quality penetrating oil into each cylinder. After repeating this and letting the oil soak for a few days, try breaking the engine free by hand.

If (or once) the engine is free, change the oil and filter. Rotate the engine until it’s in the proper position for the number one cylinder to fire and remove the ignition distributor. In the alternative, leave the engine in whatever position it happens to be and make note of the distributor position so that you can put it back into the correct position later on. Then use a suitable tool and drill to spin the oil pump. The pump’s drive shaft can be found at the bottom of the distributor’s hole. If you look at the bottom of the distributor you’ll see that the distributor shaft resembles a large flat screwdriver and this spins the oil pump driveshaft when the engine is running.

You can buy a dedicated oil pump spin tool that fits perfectly into the distributor hole or fashion your own by cutting the handle off of a long-enough screwdriver and chucking the end into a drill. Use a high-speed drill to spin the oil pump until the gauge indicates there’s pressure and then spin it for another minute or two.

The factory oil pressure gauge in your 1979 Corvette is electric, so you’ll have to put a good battery in the car and turn the ignition key to the “on” position to get a gauge reading.

With a good battery and good oil pressure, next turn your attention to the fuel system. At the very least you will have to drain all of the old fuel out of the tank and fill it with fresh fuel.

Though you may get away with not rebuilding the carburetor, it’s advisable to just go ahead and do it before even trying to start the engine. After four years of sitting idle, the carburetor is very likely to leak when fresh gas fills it up.

Visually inspect the fuel and cooling system hoses and replace any that look questionable. Also carefully inspect the wiring, which may have been damaged by rodents or other animals while the car was stored outdoors, and remedy any problems you find. Drain any remaining transmission fluid, drop the pan, and have a look at what lurks inside. If nothing is apparently amiss, replace the filter, reinstall the pan with a new gasket, and refill the transmission with new fluid.

Make sure you have at least one good dry chemical fire extinguisher within reach, say a quiet prayer, turn the key, and hope for the best.

Once the engine fires, look for fuel or coolant leaks. If all is well, set the ignition timing and adjust the carburetor. Let the engine come up to operating temperature while constantly monitoring oil pressure and coolant temperature, and checking for fluid leaks from the engine and transmission. Once the engine and transmission are good to go, you’ll next need to go through the brake system before actually driving the beast.