Parking a Car for a Long Period

A parked car can deteriorate over time. In fact, when a car sits for months or years, it's actually just as hard on the vehicle as it would be to have it running high miles. Many things can begin breaking down on a parked car.

So how do you avoid this?

The question came up in our Ask a Mechanic forums when rcasey found that his 1986 300ZX Z31 was running roughly after two years of sitting in a basement garage. He believes it was missing a cylinder (only running on 5 of 6).

Most likely, it had a plugged fuel injector, which could have been caused by a lot of things, including bad gasoline or deposits. Rcasey got his problem resolved, but what could he have done to avoid the issue to start with?

When a vehicle is to be parked for a long time, certain things should be done to keep it fresh. First, additive should be added to the gasoline to stop the fuel from separating. This is a common issue as most are unaware that gasoline can "go bad." It begins to separate, becoming varnish in the process. This makes it very bad for engines.

When I worked in a wrecking yard as a teenager, we used to "punch" the gas tanks on cars we were going to crush and drain the fuel into barrels. You could smell "bad gas" and know it was no good. If the gasoline was still good, we'd use it in the vehicles being used in the junk yard (forklifts, running cars we called "yard cars" for fetching things, etc).

Another thing is exercise. Most people don't realize this, but a car needs exercise just as you do.

The number one thing you need to do with a sitting car is use it. Take it out for a Sunday drive a few miles every month or so. Sitting is as hard on a car as are hard miles.

Running it is not the same as driving it. If you don't move the car once in a while, the rubber on it - tires, bushings, etc. - will dry and crack and require replacement. Moving parts that don't get lubricated unless they're moving, such as CV joints and such, also require exercise.

If you put additives in the gasoline to keep the gas from going bad and you run the car every month or so and drive it around, it will be able to otherwise be "parked" for years.