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How to prepare a vehicle to be driven after sitting unused for 7 months?

Since the end of September 2015 my 1991 Cadillac Deville has been sitting on the driveway untouched. I wanted to drive it again, but before I did I wanted to ask you, members of the forum, if there is anything I should do to the car prior to driving it?

The vehicle has been sitting there untouched for about 7 months and I’m concerned about the gas, potentially the oil. Just prior to it sitting there I had all of the fuel injectors replaced which cost a fortune, so I want to be sure to tackle this issue of bad gas in the best possible way.

A little aside, I know the Cadillac needs a new battery. I would also like to mention the last oil change it had was probably a year ago which I used full synthetic mobile one and I probably put a thousand miles on it since that last oil change. The Cadillac was in full working order prior to having it sit there for almost 7 months.

Any advice on what I should do is appreciated!

How old are the tires?
Even if they are holding air, if they are older than 7 years or so, they are potentially dangerous to drive on.

Seven months is long term parking.

Remove the gas cap and smell the gas. Does it still smell like gas?

If so it’s okay.

Check all the fluids, make sure critters didn’t build nests in the intake, put a battery in it and fire it up.


I agree with Tester. There are cars on dealer’s lots that have sat longer than seven months. Especially used car dealers. I’m sure rental agencies have a few that have sat for more than seven moths too before they get replaced with the new models and sent to auction.

Charge or replace the battery. The car should start and run fine. You should add marine fuel stabilizer to your fuel now and at every fill up. It seems you drive the car very infrequently and the stabilizer will keep the gas viable.

About the only thing I can add is to check air pressure in tires before you drive it .

“There are cars on dealer’s lots that have sat longer than seven months.”

That is true, but the cars on dealer’s lots may not have tires anywhere near as old as the tires on a '91 Caddy. Unless the OP knows–through documentation–that the tires were replaced more recently than 7 years ago, those tires are…risky…

He can look at the date code on the tires, they will tell the year manufactured.

Every Year I Park Cars For 7 Months. I Only Charge The Batteries In The Cars Every Month Or So During Hibernation, Keep The Tires Inflated Properly, And I Do Park Them With Clean Synthetic Motor Oil In The Engines.

When I want to start one and get it back on the road I recheck and fill the tires, open the door, get in, put the key in, start it and drive.


If the fuel filter hasn’t been replaced in some time, this would be a good time to do it, before starting the engine for the first time. Besides that, charge up the battery fully with a battery charger, and check all the levels of the liquids. The first few times driving, make sure you recheck the liquid levels and pay close att’n the dash gauges that stay in their normal range, especially the coolant temp gauge.

Thanks everyone for your input! I’ve read every post and I’ll take it all into consideration before I start up the Cadillac.