Your Car After a COVID Quarantine

Your Car After a COVID Quarantine

How sitting impacts a car: getting it back on the road

For many Houstonians, the COVID quarantine and resulting office closures have created a situation where a car has sat unused for long periods of time.  Like people, cars do are not meant to sit around.

A general rule of thumb is that a car should not sit for longer than a month without starting it up for 10 minutes.  This likely will not recharge a weakening battery, but it will circulate the fluids and keep rubber parts supple.

Today’s European Cars is starting to see cars that have not been driven for several months.  To date, all have had simple/predictable issues and only needed a comprehensive service to get back into shape.

If your car will quarantine longer than that, it should be driven monthly--a leisurely Sunday drive will keep your car happy.  If you let your car sit, parts will start breaking down and fluids will go bad.  This eventually will cause issues.

What Happens When You Let Your Car Sit

I don’t like to sit for a long time.  If I must, I get irritable and sometimes stiff.  Likewise, with your car:

  • Batteries go dead
  • Tires get flat spots
  • Gaskets and seals become brittle
  • Small leaks develop
  • Fuel goes bad
  • Engine oil deteriorates and traps moisture/condensation
  • Rust develops in the cooling system

This is not an exhaustive list, but the most common things your car might see after six months to a year of COVID quarantine.

A drained battery will probably be the first hurdle of a quarantined car.  Even though the car was “off” there are still systems drawing power—the clock always marches on, the car’s CPU consumes a little, and poorly grounded wires may continue to draw power.  We call this passive depletion “parasitic drain”.  Colder weather can exacerbate the problem and make it harder for your car to start—the cold reduces the battery’s output and thickens the oil, creatin resistance, and a slow or no start. 

On the quarantine list, the battery is usually the easiest to resolve.  Usually, a good drive or a recharge on a battery charger set at a lower output will cure it. Worst-case scenario is replacing the battery.

Tires lose air while sitting and the rubber on them becomes ineffective with longer periods of dormancy.  They crack and small holes eventually develop—you get flat spots because air is escaping from the cracks. If a car sits on a flat spot for a many months or years, you will ll need to get new ones.

Tires which have gone flat during quarantine need to be refilled to the correct pressure.  If they were old tires before quarantine, they should be examined closely. 

Gaskets, seals and rubber hoses often become problematic after sitting.  When left to sit, they become brittle and snap a little pull. Dormancy causes gaskets and seals to break down and not function properly.  Rubber hoses become stiff and don’t seal like they should; this is especially common with emissions and engine vacuum hoses.

Cars have too many seals and gaskets to review, but there are a few common failures we often repair:

Mercedes – oil filter housing gaskets and vacuum breaker plates

BMW – oil filter housing gaskets, valve cover gaskets and oil pan gaskets

W/Audi – water pump/cooling parts and O-rings, brake vacuum pump gaskets and engine vacuum lines.

Gasoline goes bad; and gas with ethanol goes bad quickly.   If gas is not stored in an air-tight container, the oxygen reacts with it and it breaks down.  Your gas tank and vapor system are supposed to be airtight.   However, the evaporative system is filled with rubber hoses, which frequently do not seal completely and air gets into the system. 

Lightly deteriorated gasoline will make your car run rough, and perhaps trigger a “check engine” light.  Often, simply adding new gas to the tank allows you to drive your problems away.

Heavily deteriorated gasoline will develop a gel-like substance, which will need to be flushed from the system.  It will clog systems and keep your car from running.

Engines deteriorate faster when not being used—even with our top-shelf synthetic Mobil1 oil.   Many drivers assume that because they don’t use their car that often, they don’t need to change the oil as frequently.  It’s actually the opposite—engine heat cycles evaporate condensation moisture which develops from sitting.   It’s the heat of running which helps with the evaporation.  Think of your house windows on a cold rainy morning and a sunny afternoon.  Same principle with a car sitting in the garage or driveway—the temperature changes lead to condensation.

Oil changes are an easy fix.  Do them every 5,000 miles or annually and you will be OK.

Weirdly enough, rust forms faster on cars when they aren’t used. Regular driving slows down the formation of rust on the outside.  When cars are stationary, the oxygen and iron have more opportunity to react and create rust as compared to a car is in motion.

How To Revive A Car That Has Been Quarantined

If you parked your car without preparing it for quarantine, no need to stress too much--you’re in a majority.   Most likely, all that is needed is a little diligence and a service at Today’s European Cars. 

If you are handy and have the tools, there are several things you can do to revive your car:

Check tire pressures and inflate to the PSI stated on the sticker inside the driver side door jam, the tire sidewall or to where you like to keep them.  Also inspect your tires.  If you see cracks, you need new tires.  Don’t forget the spare.

Check the coolant level.  Top off with regular water if needed.  This is always a good practice if you are under the hood.

Check the oil.  Again, a great habit.  If your car does not have a dipstick, look in the manual or on a maintenance screen on the car’s dashboard.  Most cars don’t have dipsticks anymore, but there is a level sensor in the oil pan and a way to access it through the dash.  YouTube is loaded with answers for this.

If you think you need new gas, do not start the car.  Instead, siphon out all the old gas and replace it with new gas. Most cars have an anti-siphon mechanism making this difficult.  A shop like ours will probably remove the fuel pump and siphon directly from the tank.

If you think the gas is probably still good, add a quality fuel stabilizer and let it sit for a few hours to remove any condensation that has possibly accumulated in the gas tank.

Next you’ll need to start the car.  Pay attention when you put the key in—is it like you remembered?  If the engine will not turn over, it’s probably a discharged battery. Try charging it with a battery charger. If a jump-start is required, be mindful of the connecting the positive-to-positive terminals and grounding correctly.

If your battery will not hold a charge once the car is running, you probably need a new battery.  We’ve had availability issues with a few of the Mercedes battery sizes—Mercedes is out of stock.  BMW batteries have always been difficult as most cars had three different sizes specified for the car; however, you should use a battery with the same specifications.  Don’t forget to program BMW batteries or reset codes on other German brands.  Don’t mix AGM and traditional batteries.

When your car starts, it may run a bit rough for a while as it works out all that gummed up fuel. The exhaust also might smell different if the gas is old.  Let it idle normally for 10 minutes. Check underneath the hood and car and for any leaks. 

If any of your gaskets went really bad, you might see some puddles underneath the car.  Make a note of what you see and the colors. Remember, most cars have under-panels, so leaks are not always apparent, and you can connect the position of the leak to the position under the car.

Oil – light brown
Transmission fluid – pinkish, except for some Mercedes, which are blue.  Usually more towards the center of the car
Power steering fluid – pinkish
Coolant – Blue for Mercedes and BMW, pink for VW and Audi.  No German modern cars should ever have green.
Brake fluid – clear and usually near a tire

Monitor the temperature of the car to make sure it doesn’t overheat. Don’t idle too long.  If you notice the temperature gauge rising, turn on the heater and put your blower motor on high.  If it still continues to rise, turn off the car immediately. 

If you notice leaks, we can help.  It is never 100% safe to drive with a leak of any sort, so you’ll have to assess whether you can drive it to us or use a tow service.  It all depends on what is leaking, the severity of the leak, and how much fluid has leaked.

We’ll probably start with an oil change and assess your car with our inspection process.  Each one of our techs has more than 10 years of experience; we can review a car efficiently.  Unless specified otherwise, we’ll review your car, build an estimate, talk to you for approval and complete the work as instructed.

Today’s European Cars offers a 24-month or 24,000 mile warranty on our repairs.  We call it the “Longevity Guarantee”.  We can do this because of the quality parts we choose and our benchmark workmanship—it gives us the confidence to offer this warranty to our








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