What Happens When You Let Your Car Sit and What You Can Do About It


A lot of us are taking a bit of an unplanned break from driving lately (to put it nicely), and with that can come a few little problems that most of us aren’t really used to having to worry about. Ironically, this whole shutdown just happened to coincide with gas prices dropping to some of the lowest levels of all time. I mean come on, that couldn’t have happened on my road trip last November?!

So while we’re still saving money on gas and there’s less wear and tear on our cars, that doesn’t mean there aren’t some drawbacks. For instance, a lot of people get excited about super low mileage cars, but me? Not so much. If I’m looking to buy a car, I tend to prefer one that has seen consistent, healthy usage with a medium to low amount of miles for a number of reasons.

So here’s what to look out for whether you’re storing your car for the winter, have a sports car that doesn’t see a lot of miles, or happen to be locked down in the middle of a global pandemic the likes of which humanity has never before seen (what are the chances of that, though?).

Cars Are Designed to Be Driven:

OK, well duh, right? What I mean is that any seals, hoses, lines, moving parts, and even tires are designed around the assumption that they will see regular use. Without running the engine, you’re not circulating oil, coolant, and other various fluids through the system. Those seals and hoses rely on fluids running through and over them to keep from drying out and deteriorating.

For a few radiator hoses or vacuum lines, that may not seem like a big deal. But something like the rear main seal? That’s a lot of work to replace. Piston rings? Ouch. That’s basically a full engine rebuild right there. Then you have moving and rotating assemblies like your valves and cams, as well as Lamborghini Countachrod bearings and of course the gears in your transmission and differentials. Starting them up without sufficient oil coverage isn’t the best thing for them.

Matt Farah of The Smoking Tire has an interesting take on this with his ownership of a Lamborghini Countach — a notoriously unreliable car, and one that is very expensive to maintain. However, that is exactly the sort of car that tends to sit un-driven for extended periods of time since their owners are afraid to put excessive miles on them. Matt on the other hand drives his all the time and has very few issues — lending credence to the fact that these cars need to be driven in order to keep them running their best.

However, these are extreme cases, and more applicable to high end sports cars and super cars than neglecting your daily driver for a few weeks at a time. So here are a few common problem areas you might run into if your car will be sitting, as well as what you can do about it.

A Dead Battery:

A car battery will naturally drain over time, even if it’s not hooked up. However it will drain even faster when connected, as there will be a slight load on the electrical system from things like alarm systems, status lights, or even the clock on the dashboard. Letting it sit will drain the battery slowly over time, and then it might not have enough to crank over when it comes time to start it.

What you can do about it:
Your battery relies on the alternator to keep the battery charged, and that requires you putting some miles on it here and there — and just starting the car and letting it idle for a few minutes isn’t enough. Just starting the car takes a solid chunk out of your battery’s charge, so you need to actually CTEK battery tenderspend some time on the road to make up for it, I’d say 10-20 minutes at least, but there are more reasons I’ll get into later on for why you want to give it more than that.

You can also use a battery tender, which gives your battery a slow trickle charge. This is often used on sports cars that don’t see a lot of use, or cars that stay in the garage for the winter.

Flat Spotted Tires:

If you let your car sit in one spot for too long, this is bound to happen. It used to be much worse back in the days of bias ply tires, but it is still very much a thing with modern radials as well. The rubber and steel that makes up the carcass and tread of the tire will begin to relax into the ground, leaving a flat spot in the tire. This might feel like your tires are out of balance, and should go away within a few miles of driving, but if left too long, this can be permanent.

This is also a recipe for your tires drying out and showing cracking and checking on the sidewall where it is exposed to the sun day in and day out Race Ramps FlatSpottersin the same spot. Without getting that rubber moving and flexing, it just accelerates the process.

What you can do about it:
Easy, just drive. Even a trip around the block or down to the store once a week will go a long way. If you plan on letting it sit for longer (say, if you’re storing your car for the winter), or have bias ply tires, there is something you can do. You can park your car on FlatStoppers from Race Ramps, which are made of a tough, concave foam that will help to keep your tire’s shape.

Rodents Can Be an Issue:

Especially if you store your car outside, you might find that a few furry critters have taken up residence under your hood or in your exhaust. In making a nest or looking for food, they often like to start chewing on wiring harnesses and vacuum lines, which can lead to issues that are particularly Rodents eating away wiringannoying to track down. Plus, many manufacturers started using biodegradable materials for their harnesses and parts that literally are food (I’m looking at you, Mercedes).

What you can do about it:
Again, just driving is usually enough, but not always. Some people swear by putting bars of Irish Spring under the hood, because apparently rats hate the smell of it as much as I do. However your mileage may vary here. My dad tried that once and they just shredded the stuff, possibly just out of spite, who knows. My best advice is just to check around under the hood every so often, or if your car has been sitting for a while.

Moisture Can Collect Where It Shouldn’t:

This isn’t quite as common as it used to be, but it will still happen. It’s inevitable that moisture will get into various places, like your fuel lines and oil. That’s because rubber hoses, fittings, and seals do a pretty good job of keeping moisture out, but it’s not 100%. This normally isn’t a problem Drive your car regularly to avoid issuesbecause you’re constantly cycling through fuel and do regular oil changes, but it can build up over time and cause corrosion in the lines, as well as diluting the fuel and oil, making them less effective.

What you can do about it:
This one is a little out of left field I know, but bear with me here… You gotta drive the damn thing. Also, it’s important to keep in mind that mileage is not the only thing that makes your oil less effective, which is why if you seldom drive the car, you still need to change the oil somewhat regularly. Also, keep in mind that your brake lines are susceptible to water intrusion as well.

Have any other questions or something I missed? Drop a comment below!

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Garrett Davis
Garrett has something of a sickness when it comes to cars, working on everything from Jeeps, to sports cars, to over-engineered German nightmares. Currently he is embroiled in an Audi Allroad offroad project, and is slowly losing his grasp on sanity.


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