I know two people, each will be storing a different car for the winter. Let’s say mid-November through mid-April. Neither car will be taken out of storage or started until spring.
Each will be in an unheated but enclosed, cement floored storage area. This is the north. We’ll have a week in January or February when we have temps in the -20° F range.
One is an early 70’s Ford. The other is a 2010 Honda.
What needs to be done to prep these cars for storage?
Fuel stablizer?
Does it makes sense to disconnect the batteries?
Mouse poison in the storage area has been suggested.
Check the antifreeze in the radiator–you don’t want it to freeze (they have antifreeze/coolant testers). You might add fuel stabilizer but for only 4 months it probably isn’t needed. Some cars have devices which run all the time (such as clocks), so you might disconnect the battery.
You might also clean out the contents on the inside of the car–those cookies and candy bars might as well be used up…
Dump some fuel stabilizer in the tank and drive the car around the block - that should give enough movement to mix in the stabilizer with the gas and get it through the fuel lines.
Pull the battery and store it for the winter. I’ve heard contradictory advice whether or not to keep the battery on a trickle/maintenance charge during storage or not. I pull the batteries out of 2 motorcycles and 2 jet skis every fall and don’t keep them on trickle charger, but just on a shelf in the basement. I put them on the charger in the spring, charge them up and re-install them, and have never had one fail on me - these are 4-5 year old batteries now with fairly difficult service conditions, especially the watercraft.
Put some mouse poison in the car. I once had a mouse/mice make a nest out of the carpet in a car I stored once. Cost me an ungodly amount of time to replace the carpet and something like $400 as well.
If you can put the car on jackstands to get the weight off the tires, I’d suggest it, but I don’t think it’s necessary by any means.
Other than that, that’s all I can think of. I’m sure someone with more knowledge will be buy shortly to add anything.
Definitely disconnect the battery. Note that some security systems and radios aren’t very happy when you do this, so check their user’s manuals for the proper procedures first. Most cars will drain the battery in somewhere between a few weeks to a few months, depending on the car. Very few will last six months without killing the battery.
You might want to jack the car up and put it on blocks to prevent flat spots from forming on the tires. In six months the tires probably won’t be too bad, and in reality if you just drive the car around for a couple of weeks in the spring any flat spots will work their way out.
Fuel stabilizer isn’t a bad idea, though usually your gas will still be ok after six months. The blended fuels they use in some areas go bad faster, from what I’ve read.
I wouldn’t bother with putting oil in the cylinders in the spring as suggested by SanDiegoTim, but that’s just my opinion. If the car has been sitting for a year or two I might though, and I would if the car has been sitting in an area close to the ocean (salt in the air causes more corrosion problems).
In the spring, the first thing I would do is drive the car around and slam on the brakes a bit hard over and over to make sure they are working freely. I’ve had brakes stiffen up a bit after they’ve been sitting for a while. This also helps to scrape off any surface rust that may have formed on the rotors.
Mostly, though, six months isn’t that long. Reconnect the battery, check the car for critters (air intake, exhaust, etc), crank it for a bit and it should start fairly easily. It’s when they’ve been sitting for a year or two that they get a bit more finicky about starting, at least in my experience.
You really only need to disconnect the negative terminal of the battery. I do this every winter for my RV and add fuel stabilizer to tank, which I fill before putting it to sleep (helps keep moisture out). I also buy one of these to help keep moisture out of the interior. But the water that collects needs to be dumped periodically. I would put a good coat of wax on the vehicle and buff it out like you normally do.
On the mouse front, you also might want to put some steel wool in the intake of the 70’s Ford. The old airboxes make perfect little mouseholes, especially since your air filter is a wonderful source of nesting material. On most newer cars the intake baffling is… baffling to rodents and so that’s less of an issue.