Are you driving a used car and hoping it will be able to keep puttering along for at least one more year? You are not alone.

According to automotive information and marketing company R. L. Polk & Co., consumers, on average, are holding onto cars longer than they have in the past.

So with cars getting older and older, it is getting more and more important to recognize problems with your car early on before it is too late.

Does that pinging noise coming from your engine mean it is on its last leg, or will a simple, cheap maintenance stop put you back on the road in no time flat?

You may not know a lot of about cars, but in-depth automotive expertise isn't necessary to stay ahead of major problems. Just keep an eye out for one of the five following warning signs ...

car alternator sitting on counter in auto parts store

No. 5: Your parts store sends you Christmas cards

Mark Larsen, a franchise training manager with Car-X Auto Service, said there is one sure sign that it may time to junk or sell a used car.

"If the parts store starts sending you Christmas cards, you know you've spent too much money there," said Larsen. "Also, when they know you by your first name and they know the names of your children."

Spending too much too frequently on repairs is a big reason to put your old used car out to pasture.

Knowing when you are better off getting rid of your car for another one is a fine line. Getting $2,000 worth of repairs on a car that is only worth $5,000 may or may not be worth it, depending on how good of shape overall the car is in and if you anticipate any other problems in the near future.

But if you walk into the parts store and realize you know all five of the employees by their first name, maybe it is time to take a drive down to the local new or used auto lot.

Next up, beware if your car seems to have an insatiable appetite for oil ...

man doing oil change on car

No. 4: Your car is burning through oil

Nobody likes to see a pool of oil underneath the front of their car. But there are even worse problems to have than an oil leak when it comes to older cars.

If a car is starting to use up a lot of oil, but you see no signs of an oil leak on your driveway or garage floor, it could be a sign the car is on its last leg.

Larsen said burning a quart a month is not uncommon, but if the engine is taking close to a quart a week there is a problem.

"The oil is just burning it up because the engine is tired and it's not tight anymore," said Larsen. "It could be the rings or the valve seals could be so hard that they just can't hold the oil anymore. It tends to be expensive (to fix)."

But that expense can be nothing compared to our next signal ...

mechanic working under car with repairs

No. 3: Pinging noises from engine

Cars make all sorts of sounds, many of them normal. All of us have been paranoid at times about a noise coming from our car that ends up being nothing. But what if it is something more serious?

A weird noise coming from your engine could mean all sorts of things, but if it is coming from the inside of the engine block, it is probably not good. Fixing something inside the engine block requires opening it up, which is always going to be expensive.

"If you have an internal engine noise that is somewhere along the lines of a crank or piston, or an internal engine noise that is something that isn't going away and is going to get worse, or a rod knock, or a valve that's got a popping noise to it -- any of those things is an internal engine problem, and that really pushes the engine to the point that it needs to be replaced," said Larsen.