BUYING AN OLD, LOW MILEAGE CAR

WHAT TO PREPARE FOR!

Author: Andre Clemente
Last updated: March 29, 2020

 

low mileage car maintenance
1988 Honda Civic with 40k original miles owned by …yours truly

Finding an original, low mileage 30+ year old “time capsule” is a beautiful thing. The glow and depth of the original paint, the factory fit and finish, the blemish-free wheels that look out-of-the-box new … what a beauty to behold.

survivor car low mileage preservation

All the original stickers, VIN#’s, and factory labels are intact. You open the door to what is left of the original new-car smell, where you hop in to sit on moist leather seats (or stain-free cloth with no rips). The gear knob has virtually no wear, and the steering wheel feels brand new in your hand. All the buttons and knobs press and turn with the precise, solid “click” that the factory intended. What more could you ask for?

low mileage cars maintenance

Unfortunately, it’s the things that you don’t see that you have to be wary of. Cars that have sat for a long period of time (regardless of miles) are prone to many issues – a large chunk of which I address below. Keep in mind, many of these issues are the result of uneducated sellers improperly maintaining (or storing!) a car that isn’t being driven.

The fact is, you’re about to make a large financial investment towards the old car of your dreams. The items addressed below are for the people who want to drive their car regularly, as well as take as many precautions as possible.
 

FUEL SYSTEM

Some of these “survivor” garage finds haven’t been started in 10 or 20 years. What does that mean for you? 10 or 20 year old gas! Gasoline itself can last for months, even years – but only if kept in a sealed, air tight container. Your 20+year old fuel system is no longer air tight like it was intended from the factory – outside air and moisture exposure decreases the life (and octane rating) of gasoline substantially. Sure, the car may start and run, but the gas will be full of water and completely degraded.
Varnish and gummy deposits will form, clogging carburetor jets, injectors, and even stick to intake valves. Also, ethanol can cause rubber fuel hoses to deteriorate from the inside out, leading to pieces of hose innards flaking off and getting sucked into the fuel delivery system. Moisture forms along the walls of the gas tank, which in turn get absorbed by the ethanol in gasoline (ethanol is hygroscopic. When people say “gas can go bad in as little as 30 days”, they’re not kidding – they are referring to the ethanol absorbing water).
preserving a survivor collector car
 
What to do: Siphon or drain out that bad gas! Why risk clogging up your system? If you want to be extra thorough, have the gas tank flushed and cleaned. While your at it, go ahead and replace the fuel pump and fuel lines. Seem a bit extensive? Not if you want your car to run as good as it looks! You need to budget for this service before you buy that “barn find” – use it as a negotiation tactic to bring the price down. Those who are familiar with air-cooled Porsche Turbo’s, for example, aren’t new to replacing or cleaning the entire fuel system before starting after even just a few years of sitting. Consult your enthusiast clubs and forums for the particular car you are looking for, and they should guide you in the right direction (as well as any credible repair shops for your make of car).
 

ENGINE OIL

Engines are designed to run on a normal basis – not sit for years untouched. Cars that are driven frequently (and maintained properly) run happier and more efficiently than one that sits all the time. Your Owner’s Manual clearly states to change oil every X miles OR every X months – and there’s good reason for it.

A sensible car enthusiast knows to change the oil on time, regardless of mileage in between intervals. Unfortunately … not every seller is a sensible car enthusiast. Constant short drives before operating temperature is reached will eventually turn the oil into a thick sludge. Oil will get contaminated with moisture, and overtime it will oxidize, break down, and change its viscosity.

Under low temperature operation the oil essentially deteriorates by contamination rather than by oxidation. The mixture of water, oil and contaminants form a mayonnaise-like sludge which tends to settle out of the oil on the bottom of the oil pan and in other areas of the engine not sufficiently washed by the oil.” – Lubrication Engineers Technical Department.

This sludge can also clog your car’s CCV system (if so equipped) as well as other oil-related systems on the vehicle.

What to do:Change the oil immediately! Unless the car had a recent oil change, make it a standard for yourself to change the oil as soon as you buy a car. The color on the dipstick will only tell you half the story. If it’s been sitting for a decade with occasional cold starts, it would be a good idea to remove the oil pan and inspect it for sludge. There’s no sense having fresh oil mix with the contamination at the bottom of the pan. Again, this applies to cars that have been sitting for years, regardless of mileage.

If you are inspecting a car for purchase, remove the oil cap and check for white sludge. Moisture that doesn’t get burned off will condensate on the cooler parts of the engine (such as the valve cover), as well as parts that rarely get washed with oil (such as the oil cap). If you see white sludge, don’t start it! Instead, show it to the seller and negotiate the price down. However, if everything looks fine, disable the fuel supply and dry-crank the engine to prime before starting (if the seller will let you). Moisture in the crankcase will burn off when the engine reaches operating temp.
 

RUBBER

Ever wonder why old, low mileage cars produce oil leaks when driven for the first time after sitting for years? Or why the car doesn’t feel “tight” and composed on the road, like a low mileage car should?

To answer, lets first go over some facts about rubber:

  1. All rubber has a shelf life, regardless of use.
  2. Rubber has memory, and it can lose this memory when compressed for a long period of time.
  3. Rubber does not have to be “dried out” to lose its ability to seal
  4. Rubber will get eaten alive by ozone (known as “ozonolysis”), especially if the car is not kept indoors.

If the car is stored outdoors, expect the rubber to deteriorate fairly quickly. The UV from the sun causes the oils within the rubber to evaporate (oils known as “plasticizers” and “polymer additives”), leaving a rock-hard surface that cracks (or even crumbles) upon contact. Ever wonder why interior dashboards crack? The plasticizers and additives in the dash slowly evaporate in the sun, leaving a faded and cracked dash. On cars that have sat in the sun for many years, you’ll notice an oily film/residue on the inside of the windows – this is oil that has evaporated from the dashboard (as well as other rubber and plastic interior parts).

Even rubber that doesn’t see the sun (suspension bushings, etc) will still harden and crack from ozone damage (“Ozone” is literally O3. It is naturally created when UV reacts with 02 in the atmosphere). Ozone is all around us (in small amounts) and exposure to ozone will break down rubber over time.

However, the rubber on cars kept indoors will stay soft for decades. Does that mean it is still good? The answer is no!

Just because the rubber on your low mileage, “garaged since new” car feels soft and moist does not guarantee it can still seal properly! Rubber, when compressed for an extended period of time, will eventually lose its memory (ability to return to its original shape). Weatherstripping, engine gaskets, etc all remain in this compressed state for years – whether the car has seen 10k or 100k miles! As soon as you start using the car regularly, the rubber will loose its ability to seal (engine parts expand/contract with heat, weatherstripping decompresses from opening and closing the doors, etc). This applies to all rubber parts of the car, including suspension bushings, rubber lines, etc.

What to do: Don’t be surprised to see oil leaking from valve/cam cover gaskets (or anywhere else in the engine bay, for that matter) after driving the car for awhile. If you plan on driving the car regularly, you’ll need to replace all fluids, so it would be good idea to replace rubber hoses while the systems are drained. Plus, it’s a great time to get acquainted with your engine compartment. You do NOT want to have oil all over your pristine engine bay!

If you want the car to drive and handle as good as it looks (like a new car), considering replacing as much of the suspension and steering bushings as your budget allows. It isn’t cheap, but the enjoyable driving experience that follows is well worth the investment. The ride will be better, the steering will be sharper, and the handling will be closer to what the factory intended.

maintaining a low mileage car that has sat

 

TIRES

With the hundreds of cars posted on this site, it is not uncommon to see a few sitting on their original tires. (Fun fact: the original spare is filled with air from the same year the car was sold new!). The original tires might not mean much to you, but certain high end sports cars came with unique tires (in rare sizes) that are no longer produced today. By all means, keep and preserve them in for originality sake, but do yourself a favor and do NOT drive on them. As mentioned previously, all rubber has a shelf life! The life expectancy of a tire is based on its use, maintenance, how it is stored, and its physical age. While cracking and worn tread are obvious signs that replacement is needed, an important concept to understand is that bad tires may not show any obvious visible signs of needing replacement.

preserving tires old car thats been sitting

Wonder why the tires on a low mileage car can feel rock hard? Oils evaporate from the rubber over time, and the chemical bonding eventually disintegrates – resulting in a “rock hard” tire. These tires will not hold air like they used to.

In fact, all tires lose their ability to hold air over time. When a car sits for a long period, the tires get flat, – resulting in “flat spots” within the tire. Even the most finicky of collectors fail to maintain proper tire pressure while the car is stored. For a bias-ply tire, this can be detrimental.

Radial tires, by design, will “roll out” most flat spots once you begin driving. However, re-inflating a tire that is flat or highly under inflated is a great way to reduce the life of a tire. “A tire that is consistently 20% under- inflated can last 20% less.” –Michelin Tire.

What to do: Look at the date code on each tire. If a tire is more than 6 years old, get them replaced – especially if you plan on driving the car regularly. There is a reason manufacturers insist on new tires after 6 years, regardless of mileage or tread life. It’s not worth compromising your safety out on the road just to save money! Even if it is less than 6 years old, conduct a complete visual inspection for cracks and dry rot. Crank the wheel and look at both sides of the tire, as the inner tread could look substantially different than the outer tread in regards to wear, due to factory camber settings or worn suspension/steering components. If you plan on letting the car sit, be sure to move the car around and maintain tire pressure to reduce the potential of flat spots.
 

BRAKES

It is common knowledge that brake fluid absorbs water. What isn’t common knowledge is just how well and how quickly brake fluid can absorb water, as well as why this is a good thing:

  1. Exposed brake fluid can absorb enough water in one hour to be ruined.
  2. On average, brake fluid accumulates 3% water after 18 months in the typical sealed automotive brake system.
  3. 3% water content in brake fluid reduces the overall boiling point by 25% (water has a much lower boiling point than brake fluid, as well as a higher freezing point).

The fact that brake fluid can absorb any moisture that enters the system is a positive thing. For one, moisture that is absorbed is dispersed throughout the fluid, preventing localized corrosion (this in turn slows the overall rate of corrosion from water within the system). It also prevents water droplets from forming … which could boil and freeze within the system.

You will notice that brake fluid has two boiling point ratings. A dry boiling point (0% water content) and a wet boiling point (3.5% water content). Even in a perfectly functioning brake system, brake fluid reaches its wet boiling point within two years, which is why manufacturers recommend a two year interval for brake fluid flushing.

What to do: The first thing you should always do is lift the cap and check the fluid – it will tell you much of what you need to know. Low fluid level indicates a leak in the system or worn brake pads. Dark fluid means it is contaminated and needs replacement. Even if the fluid looks good, you still don’t know how much water has been absorbed.

If a car has been sitting for a long period, expect a spongy brake pedal. In addition, wheel cylinders and caliper seals will dry out over time, causing them to shrink and initiate leaks – resulting in a low pedal.

Bottom line, prepare to conduct a brake fluid flush shortly after you purchase the car. Just like an oil change, bleeding the brakes is something I do immediately once I purchase a car, as most sellers never think about changing brake fluid during their ownership. You will have much more confidence during spirited driving when you have a firm pedal, and considering there are automatic “power” bleeders out there that make this a one person job, there’s simply no reason to skimp on it.

Of course, make sure there are no leaks in the system before you begin bleeding. Start off by pressurizing the brake system using a power bleeder. Then look underneath the car and check for any fluid dripping from the caliper/wheel cylinder area. Also note if any of the brake components appear “soaked” from leaking for a long period of time. Sometimes you won’t spot a leak, but will still have a low pedal (pedal fades toward the floor) when driving after bleeding. This symptom indicates a leak in the system, so if no external leak is visible, there is most likely an internal leak within the master cylinder.

A common myth is that a low pedal is a result of worn brake pads. This is not true. Disc brakes are self-adjusting – the caliper pistons slide outward to compensate for brake pad wear and clearance (this will result in a low fluid level in the master cylinder). Most drum brakes are also self adjusting, but there are a few that lack this feature. In this (rare) case, a low pedal can be the result of worn drum brake linings.

 

AIR CONDITIONING

If a vehicle has been sitting for a long time (whether indoors or outdoors) expect the refrigerant to be low. Even in a perfectly functioning system, cars leak an average of .5 oz of refrigerant every year through the front compressor seal alone. When the A/C isn’t used, oil isn’t circulated, and seals can dry up. This not only allows refrigerant to leak out, but it allows moisture to come in.

Moisture is the no.1 contaminant of an A/C system.

Air conditioning diagnosis and service is such a misunderstood topic that NOC has written a separate article on the subject of A/C service. I highly recommend giving this a read before tackling your A/C system, as there are many facts you should know before using a DIY recharge can from the auto parts store and before converting your R12 system over to R134a.

The article also explains why it is bad to run the A/C when it is low on refrigerant. Once the A/C is fully charged, it is important to use it on a regular basis. Don’t think that by using your A/C less, it will last longer. The exact opposite will occur. You want that oil circulating and lubricating!

 

Conclusion

While every car can have their own unique problems from sitting, you are at least aware of the common issues you will face when buying a low mileage car. Most of these issues result from incompetent or uneducated owners neglecting to care for the car as much as you would. This article was written to provide car enthusiasts and collectors a reminder of not only what to look out for, but how to maintain and preserve the cars they purchase on this site for the next owner. NOC wants to see these cars driven and preserved for years to come, and it all starts here with the basics.
 
Other articles you may enjoy:

How To Confirm Original Paint On Any Car
Orange Peel: Why Your New Car’s Paint May Look So Bad
Those Paint Defects Most Likely Aren’t From The Factory
What A Paint Thickness Gauge Really Tells You
…and more, in the Tech section!
 

Author:

Andre Clemente, Founder of New Old Cars, LLC ©
Article last updated: March 29, 2020
 

Additional Article Sources:

Gilles, Tim. Automotive Service: Inspection, Service, Repair – 4th Edition. Delmar, Cengage Learning, 2012. Print

Lubrication Engineers Technical Department: Motor Oil Degradation

Superior Sealing Technology: Elastomer Properties: Temperature

Tire Rack Technical Department Tire Tech: Tire Aging, Part 1

Tire Rack Technical Department Tire Tech: Tire Aging, Part 2

Tire Rack Technical Department Tire Tech: Flat-Spotted Tires

Understanding the Link Between Ozone and Rubber Deterioration

Science Direct: Ozone Cracking

…and many more! NOC takes incredible pride in posting only the most accurate information with the help of credible sources. Now, because some links are no longer active, not all sources are posted here. These links have been removed from the source’s website for unknown reasons. However, NOC downloads and retains all sources used to stand by every statement in this article. This is done for all articles on our website, and NOC is happy to share this information with the public. Your trust is our number one priority.

 

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