Part of being a detective is noticing the small things that others might miss. A subtle sound here, a faint odor there ... It could all add up to trouble if you don't take action now. Troubleshooting a car's strange behavior when something is going wrong can work the same way. By paying attention to the clues your vehicle is providing, you can head off an expensive problem that's building or avoid being stranded in the middle of nowhere.
With this quiz, we're officially deputizing you to be an automotive detective! We'll give you the symptoms — all the clues you should need to wrap the case — and you'll provide us with the culprit. You'll need to use all your senses to hunt down some of these problems, so don't be shy about rolling up your sleeves, getting your hands dirty, listening for a telltale sign, or sniffing out a troublemaker. You don't get to be an automotive detective without diving deep into what might be wrong with your automotive partner. You're a team; if it's got a problem, you've got a problem.
Earn your automotive badge by acing this quiz! It doesn't matter if you're a loose cannon with no respect for authority and refuse to do things by the book or a grizzled veteran who only has five days until retirement. There's room for you on our force!
You're about to stake out a suspect's business when the "Check Engine" light pops on. What should you do?
Ignore it and see if it turn back off.
Cancel the stakeout and head to the mechanic.
Pop the hood and see if anything is leaking.
Check to see if the gas cap is on tight.
The "Check Engine" light can come on for different reasons, but the easiest to check (and eliminate) is the gas cap. if it's loose or damaged, the car's computer will throw an error code. Make sure it's tight and see if the light goes off. Otherwise, make an appointment with the mechanic to get it looked at.
You're about to head to the station when you see a puddle under your car. What's the first thing you should do?
Call a tow truck.
Call the bomb squad.
Call your mechanic.
Identify the fluid.
Finding fluid under your car is (usually) never good. The only time your car can form a puddle without alarm is if the fluid is just condensation from the A/C compressor. Find out if the puddle is water, oil, coolant, brake fluid or something else, and the area it's coming from. This is a vital clue about what's happening.
Your mechanic tells you that your fuel pump has gone the way of the angels. What could have been a reason for this?
Driving with an empty fuel tank
When you drive around constantly on "E," you're putting your fuel pump at risk. The fuel in the gas tank helps to cool the pump, so when the tank is eternally almost empty, heat buildup can damage the pump. Splurge for a full tank every now and then.
You discover that a dirty rat has put some sugar in your gas tank. What will most likely happen?
It's an urban legend that we've all heard — sugar in the gas tank will disable your enemy's car. The truth is that sugar doesn't dissolve in gasoline and, since it is heavier than gas, it will just sit at the bottom of the tank. The worst it can do is clog your fuel filter, which traps the foreign matter and doesn't allow it to do any damage to your vehicle (that's what a fuel filter is designed to do).
You press the brake and the pedal feels spongy and soft. What's your reaction?
"Someone's cut my brakes!"
"There's an issue with the brake fluid."
We're not saying the bad guys DIDN'T mess with your brakes, but the most likely option is that there is either air in the brake line or the fluid has gotten old and is absorbing water (which keeps the fluid from applying hydraulic pressure efficiently). Whatever the case, have this checked out before it becomes a more pressing issue.
Your automatic transmission is suddenly shifting like it's possessed, and there are strange grinding sounds. What's happening here?
You don't have enough transmission fluid.
When your car's automatic transmission starts shifting unexpectedly, you hear a grinding sound and there are spikes in your RPMs, the most likely cause is low transmission fluid. Get it checked out before a bill for new transmission fluid becomes a bill for a new transmission.
The smell of rotten eggs is wafting through your car. What is the most likely culprit?
Someone's put an egg up your tailpipe
Sulfur in the gas tank
A bad catalytic converter
When you smell sulfur while your car is running, it's not a rival detective moving in on your case. It most likely means the catalytic converter is going bad and not transforming the chemicals from the internal combustion process into less harmful gases. Eggs on the OUTSIDE of your car means you've cultivated enemies.
You have your car towed in and the mechanic delivers the bad news — your engine has seized. What caused this?
Your engine overheated.
Your engine was running without oil.
To get to this point, you've probably ignored some pretty clear signs — puddles of oil under your car, the oil pressure sensor lighting up on the dashboard, loud knocking coming from your engine and more. Finally, the engine just up and died, and while that's bad news for you, the mechanic probably walked away smiling, thinking about the labor bill to come.
You smell burning rubber while your car is on the move. You're not going fast enough to generate that smell. What could be the cause?
Low tire pressure
A leaky radiator
A faulty oil sensor
A loose hose
If you're not chasing the bad guy — or being chased by the bad guy — and you smell burning rubber. you could have a rubber hose that's loose and is coming into contact with a hot part of your motor. You literally could be burning rubber. It could also mean you've got a leaky oil gasket somewhere in the engine. Check for hoses first; it's the easiest thing to rule out.
While you're tailing a suspect, you think you smell syrup. What could be the cause of this?
You haven't had a decent meal in three days and you're hungry.
Your transmission is leaking.
You have a faulty heater core.
The active ingredient in antifreeze — ethylene glycol — is a sweet-smelling substance, and if you're smelling it inside your car, it means you've got a coolant leak, and the heater core is a likely suspect. Also, if you're fantasizing about pancakes, be sure to eat, even if you're on a stakeout.
You're changing your spark plugs and notice that the end is black and oily. What could be causing this?
A bad valve cover gasket
When the end of the plug is oily, it means oil is getting into places where it shouldn't be. One cause of this could be a faulty valve cover gasket which is supposed to seal the spark plug port. Get it checked out because oil leaks are nothing to mess around with!
What could be the cause of light-yellow foam on your car's dipstick?
Not enough oil
Too much oil
Just as running your car's engine with not enough oil can be bad for it, putting too much oil in can damage the engine. The oil gets whipped by the spinning crankshaft and a yellow foam starts to form. Drain off a little, and pay attention to the manufacturer's recommended oil volume.
You're having trouble starting your car, and there's a whining sound coming from the area of the gas tank. What should you inspect?
A bad fuel pump
When your car doesn't want to start and there's a whining noise coming from the gas tank, you've got a bad fuel pump. The engine might also sputter, and your gas mileage may fall like a rock. Get it checked out before it completely gives up the ghost.
The mechanic tells you that you need new tires. What can you use to see if he's on the up-and-up or trying to pull a fast one?
Stick a U.S. penny into the tire's groove so that Abe Lincoln is upside down. If part of his head is covered by the tread, your tires have more than 2/32 of an inch of tread, and they have more life in them. If you can see all of Abe's hair, however, your mechanic is shooting straight with you, and baby needs new shoes.
You're on patrol when you hear your car make a clunking, creaking sound. What's the situation?
Your suspension is worn.
If you notice clunking or creaking sounds as you drive, especially when you go over bumps, it means that a shock or strut in your car's suspension system is giving out, or certain elements of the system need grease. Get it checked out, and keep your ride quiet. You can't sneak up on suspects in a clunky vehicle.
You're in a high-speed chase! Suddenly, the power steering cuts out and the car's temperature starts climbing. What just happened?
The radiator has blown.
The transaxle has just broken.
The head gasket has blown.
Your serpentine belt just broke.
The serpentine belt runs through your engine and connects several systems, including the alternator, the power steering pump, the air conditioner and, in some cars, the water pump. If this critical belt gives way, you'll notice it first with the steering.
You notice that your car's tires are wearing strangely — the outside edge is noticeably worn. What's the cause?
You're hitting the curbs too often.
The camber is off.
The camber of your tires — sometimes called the "angle of attack" in racing — describes the angle at which the tread makes contact with the road. If the camber is off, one side of the tire makes more contact than the other, resulting in uneven wear. If you notice this start to happen, get the suspension checked out.
Your car is steering harder than it used to. What should you have looked at before your next chase?
The brake rotors
Tie rods and rod ends
The tie rods and rod ends are part of the suspension system that keep your tires working together and turning with the steering wheel. If you notice that there's increased resistance when you make a turn, it probably has something to do with these components.
You are picking up a distinct vibration when the car's engine is running. What's the probable cause?
The engine and transmission are held into place by mounts that keep them in place tight against the frame. When the rubber on these mounts wears, or if the mount is failing, the vibration of the motion of the engine or transmission will be felt in the frame — and by you.
You're creeping up on a suspect in your car when the sound of the engine becomes insanely loud. What blew your cover?
The exhaust manifold
The muffler helps to deaden the noise of the internal combustion process. When the muffler develops a hole, that sound quickly becomes unmuffled and your car starts to roar. Replacing the muffler is the only way to quiet the beast and get back to silent pursuit.
After you use the defroster, you notice that inside of your car's windshield has a sticky film. What could be causing this?
Someone's put a candy bar in your tailpipe.
There's a coolant leak.
If your antifreeze is going places that it shouldn't, that can cause all sorts of problems in your car — a sticky film on the inside of the windshield after running the defroster is one of them. Check the coolant level (after the car has cooled down) and see if the level is low.
There's a grinding sound every time you apply the brakes. What needs to happen for this to go away?
Flush the braking system
Replace the brake rotor
Replace the brake pads
The brake pads slow or stop the vehicle by creating friction with the brake rotor. The pads will wear away over time, and you'll hear a grinding noise when the brakes are engaged that will get louder over time. Get them replaced before they start to scar or warp the brake rotor!
You hear a ticking sound when the engine runs. What's the best course of action?
Run! It's a bomb!
Put more radiator fluid in the coolant system.
Change the distributor cap.
Change the timing belt.
The timing belt keeps the crankshaft and the camshaft in sync so your car can function properly. When this belt starts to wear, it'll make a ticking sound. If it breaks or comes loose, you'll be going nowhere. Getting the belt replaced now will save you from having to call a tow truck later.
The squealing sound coming from under the hood is getting louder. What's the most likely suspect?
You're running low on oil.
Your car is overheating.
A tensioner is loose.
Belts under the hood of your car stay taut thanks to tensioner pulleys located throughout the engine. When one of these tensioners starts to wear out, the belt will become looser and start making a squealing or chirping noise. Get the tensioner repaired, and keep the pressure on the belt!
When you check your oil, you notice white foam. What's the most likely cause of this?
Too much additive in the oil
A damaged head gasket
The head gasket keeps the oil, coolant and other fluids from mixing within your engine. When the oil has a white foam to it, that means water or coolant has contaminated the oil system, which means a gasket has failed. Get your car into the shop pronto!
In the old days, a gumshoe could disable a suspect's car by simply removing which part?
The distributor cap
Back in the old days, cars had distributor caps and points that fired the spark plugs and made the internal combustion process happen. They were fairly easy to remove, and no distributor cap meant no ignition, and the car was stuck. Modern cars have ignition coils and toothed timing wheels, which are more efficient (but make it harder to easily disable a vehicle).
Your engine seems to have a mind of its own when it comes to heating. Sometimes it's over, sometimes under. What gives?
The car's computer is faulty.
You have a bad thermostat.
The thermostat is a valve that detects when your engine has reached its operating temperature and then opens to release coolant into the system. If this valve goes bad — gets stuck open, closed, or doesn't operate correctly — it will affect your engine's temperature.
Having trouble starting, the engine misfiring, poor gas mileage and the "Check Engine" light are all signs that what has gone bad?
The intake manifold
The exhaust manifold
The car's computer
The car's computer — usually called the Engine Control Module, or ECM — controls many systems in your engine, including how much fuel to add to the air for the most efficient combustion. If this module goes bad, the system goes out of bounds quickly.
You're hotter inside your car than a guilty suspect in the interrogation room. Which of these could be the problem?
The car is overheating.
The car's thermostat has failed.
The A/C compressor has gone out.
The A/C compressor works to pressurize the refrigerant in the system and sends it to the condenser, providing cool air to the cabin. When this part breaks down, it can make loud noises, leak refrigerant and throw other symptoms, the biggest one being warm air comes out of the vents and never cools down.
You press down on the accelerator but it takes forever for the car to go faster. What do you need to check before the criminals get away?
The accelerator pedal
Throttle control cable
Over time, the throttle control cable, which attaches the accelerator pedal to the throttle, can become stretched or loose. When this happens, the pedal won't open the throttle properly and acceleration will suffer. Repairing or replacing this part should get everything moving again.
You tell the motor pool mechanic that there's something wrong with the carburetor. Why is she now laughing?
Modern cars don't have carburetors.
In older cars, the fuel/air mix needed for internal combustion was created by the carburetor. In modern cars, this job has been taken over by the fuel injection system, which atomizes the fuel into a mist for better results.
She could hear it when you pulled in.
Nothing ever goes wrong with a carburetor.
She just replaced your carburetor and it needs time to adjust.
What is one of the most difficult problems to track down in a malfunctioning car?
Every detective has his or her open-and-shut cases and cases that take a lot of deduction to figure out. Because the problem may be intermittent or affect different systems in odd ways, electrical problems in a vehicle can be some of the toughest issues to track down.
You've put a lot of miles on your car lately chasing down suspects, and the center of your tires are looking particularly worn. Why would that be?
You've been going over some rough terrain.
The tires are under-inflated.
The tires are over-inflated.
If you notice that the center part of your tires' tread seems to be wearing faster than the outside edges, you've probably got too much air in the tires. Check the pressure recommended by your manufacturer, and make sure that's how much you're putting in each tire.
You pull up on a stakeout at night and notice that your headlights are pretty dim. What's the issue?
Your headlights need to be cleaned.
Your battery is shot.
The headlight bulbs need to be replaced.
The alternator is going out.
When the alternator starts to fail, your car's electrical system will start to show telltale signs, such as dim headlights, slow-moving power windows and the battery losing its charge. Get to the mechanic before the battery dies completely and you're stuck in the parking lot.
You feel a vibration when you apply the brakes. What's causing the shakedown?
Warped brake rotors
When you feel a vibration through the brake pedal when applied, it's typically because the brake rotors — the rotating discs the brake pads grab for the friction needed to stop the car — are worn or warped. If they're not too warped, sometimes they can be turned back to true; if they are too warped, they'll need to be replaced.