It could be said that for cars, there is no such thing as “maximum mileage.” This Honda CRX Si went a long way to prove the deal. But barring preventive maintenance on a meticulous level, what precisely happens when a car’s odometer hits the wall?
The term “maximum mileage” varies depending on who you ask. Routine maintenance in the proper places can make a car last nearly forever. Nevertheless, here are seven signs that your car is nearing retirement age and you need to either replace the engine or the car.
1. Loss of Engine Power
As an engine accumulates mileage, it will experience failures that lead to a loss of power. Consider the following for older engines.
- Worn valves, piston rings, and piston rods
- Camshaft degradation
When valves and piston rings fail, the engine loses compression and the power of its youth. These rings seal the engine combustion chamber to induce compression. Without high compression, the air/fuel mixture has more difficulty igniting from a spark.
Piston rods hold engine pistons in place and transmit their power. One engine cylinder means one rod. When a piston rod isn’t doing its job, the engine can’t either — or rather, not as well.
A camshaft is a long rod beneath a housing on the engine block. Using a timing belt, the rod rotates to move pistons inside the block. A camshaft that’s worn or out of position can reduce engine power or even prevent the car from starting.
Other parts of an older engine can fail, too, such as bearings, seals, and tappets, but you get the idea. All of these issues can occur as a car reaches maximum mileage.
2. Burning Oil
Related to some of the above issues that cause loss of engine power, we have excessive oil consumption.
As a car approaches maximum mileage and hasn’t experienced good preventive maintenance, it will likely burn more oil. You may notice blue smoke from the exhaust or even rising from the engine block.
So what about all those crooked numbers on the odometer that causes an engine to burn too much oil? One common issue is worn-out piston rings, which can cause oil to leak into the combustion chamber. The engine may also consume oil due to worn valve seals or guides, which lets oil encroach upon the intake system.
A car with high mileage may have worn cylinder walls or a damaged cylinder head gasket, which can cause oil leaks that are not only messy but dangerous. The oil could burst into flames while you’re driving.
The car may also run hotter, leading us to symptom number three.
3. High Engine Temperature
By “high engine temperature,” I don’t mean the dashboard temperature gauge moving into the red (if it does this, pull over because you’re at risk of the car’s radiator exploding).
Rather, the gauge may be creeping up past the operating temperature of your engine’s days gone by.
The standard operating temperature for most cars is about 200°F. If it consistently runs hotter, perhaps the water pump is failing. This one’s easy enough to fix. Or maybe the thermostat is stuck — again, not a big issue. A rotting radiator can be swapped out with some effort.
On the other hand, Max mileage engines may have a worn head gasket that causes oil to leak into the spark plug chambers (again, very messy and dangerous). You may also have a faulty oil pump that doesn’t get enough lubrication for moving parts.
That worn head gasket can also make your car produce a lot of white exhaust smoke, the number four sign on our list.
4. White Exhaust Smoke
In most cases, heavy white smoke from the exhaust — and I mean heavy — means a blown head gasket. This white smoke is bearable while the throttle is open and encompassing while the engine is idle.
Waiting at a stoplight, these max mileage cars can become surrounded by a cloud of smoke as the car suffers from coolant burn. Along with allowing oil to leak, a blown head gasket lets engine coolant into the cylinders, where it promptly gets fried, releasing white smoke as a byproduct.
Other causes for coolant leaks include damaged cylinder heads and, in extreme cases, a cracked engine block. Cars with maximum mileage can suffer both, to which most mechanics would advise the replacement of the entire engine.
5. Heavy Fuel Consumption
Today’s cars are fuel efficient, with many getting well over 30 miles per gallon. High-mileage cars are less fortunate.
If the gas station clerk knows you by name or the station has named one of the pumps after you, your car is using too much gas. Some things that cause heavy fuel consumption in high-mileage vehicles include the following.
- Worn fuel injectors and oxygen sensors.
- A failing suspension system.
- Loss of engine compression due to worn gaskets.
- Overall greater friction between the engine’s moving parts.
If your car is approaching 200,000 miles and uses a lot of gas, it’s likely reaching what casual drivers would call maximum mileage. I say casual because, with preventive maintenance and good driving habits, any mechanical problem is laid to rest before it’s born.
6. Rough or Hesitant Shifting
High mileage transmissions, whether automatic or manual, may not shift as smoothly as they used to. Automatic transmissions might give the car a jolt as they move between gears, whereas manual versions can become difficult to shift.
Wear and tear on the transmission’s internal components, such as gears, bearings, and synchronizers, impact ease of movement. As these components wear out, they cannot engage or disengage gears — or have a hard time trying — leading to more effort from the driver.
A bad torque converter can also cause shifting issues. A torque converter is a circular device with a hollow cylinder in the middle that transfers power from one rotating unit to another. I mention them for maximum mileage cars because they’re expensive to replace — up to $1000 for parts and labor.
And then, we have the transmission linkage, which consists of bushings, rods, and joints. The linkage connects the transmission to the shift lever. As parts fail, shifting from gear to gear gets more difficult or even impossible.
7. The Car Is Noisy
Maximum mileage cars are often noisy. Maybe it doesn’t bother you but think of your passengers.
A typical internal combustion vehicle has hundreds of moving parts; not all will keep quiet as they age (this goes for human beings, too). Squeaks, creaks, and rattles eventually become commonplace.
Some causes for unwelcome noise in a max mileage car include the following.
- Worn bushings that no longer provide cushioning between parts (arthritis for your car)
- Deteriorating framework due to rust or worn suspension parts such as ball joints or, again, bushings
- Sagging door hinges
- Lack of overall engine lubrication, which creates a dry, raspy sound from under the hood
- Aging parts in the steering mechanism
Nor does the car need to be running for noises to occur. Maybe the frame creaks when you sit down. Perhaps the hood squeals when you lift it. You get the idea — old age equals funny noises.
How to Prolong the Life of Your Car
I’ve preached the virtues of preventive maintenance in this piece because it does change the definition of “maximum mileage.” Regular fluid changes, belt/chain replacement, coolant flushing, and filter cleaning make a world of difference.
When something does go wrong, pounce on it quickly. That check engine light isn’t on to make the instrument cluster look prettier. Something’s up, and the longer you let it slide, the worse things will get.
Driving habits also make a difference. For example: Revving the transmission to the red line for every gear all the time might be fun, but it will eventually affect both the engine and the transmission.
I won’t wriggle my index finger any further. Remember that it all boils down to taking care of the car that takes care of you.
A lot of things happen when a car reaches maximum mileage. None of them are good — except for the idea of owning something for a long time.
Most car parts that fail with age are inexpensive to replace. It’s the big things you have to worry about, such as transmissions and head components and structural integrity. You might have to consider getting a new engine or selling your car when the structural integrity of important components is in question.