If your car has an oil leak, what color fluid would you find on the ground underneath it?
An oil spot under your car will be brown fluid. Most of the time, it'll be because of wear-and-tear on gaskets, seals and connections — and don't forget to check the oil pan seals, which are under the car.
True or false: A faulty thermostat is a common reason for a car engine to overheat.
The thermostat's job is to block the flow of coolant to the radiator until the engine has warmed up. A broken thermostat won't let coolant reach a hot engine, thus causing it to overheat.
Which is NOT one of the three things your car's engine needs to start?
For your car's engine to start, it needs to have good air/fuel mixture, compression and a spark (provided, of course, by the ignition).
Your steering wheel is vibrating and you can feel your car shaking, especially when you're idling. Sometimes it even stalls at a red light. What's going on?
If your car's engine is shaking so badly you can feel it in both your steering wheel and your seat, there's a misfire problem, often indicating a worn spark plug, a bad spark plug wire or a clogged fuel injector.
Why might your passenger complain of feeling vibrations in the passenger seat?
Excessive engine vibration, usually because bad motor mounts aren't holding it securely, can be felt on the passenger's side of the car.
What does it indicate if your car's engine oil turns from amber to a foamy, milky white?
Motor oil changes color from nearly clear or amber to dark brown and almost black, depending on how dirty it is. But if it's a foamy, milky white, that means some antifreeze (or water) has contaminated it, and you'll want to look into what could be leaking from the car's cooling system.
Which is the most common symptom of a seized engine?
Although all of these are symptoms your car's engine has seized or is about to seize, the most common sign is complete engine failure. Which is exactly as bad as it sounds.
If an engine's knocking noise is less of a "ping," and instead more of a deep hammering noise, what could be the cause?
A deep knocking that sounds more like hammering than pinging is called a "rod knock." This happens from wear-and-tear or damage to the rod bearings — and it's a fatal engine problem.
What does it mean to "throw a rod"?
"Throwing a rod" means a connecting rod, which connects a piston and the crankshaft, has broken. It makes a sound exactly like you'd think — a metal rod knocking under the hood, doing all kinds of damage — and is pretty much guaranteed to ruin your day. Don't even try driving it to the shop, just pull over and call a tow.
The engine turns over but won't start, you smell gasoline...and is that a puff of dark smoke coming out of the tailpipe? What could this trio of symptoms indicate?
Together these symptoms usually indicate the car's engine is flooded. Now what?
What should you do if your engine is flooded with fuel?
This can happen when the mixture of fuel and air gets off balance, most commonly in cars that have a carburetor instead of fuel injection. The best way to solve it is to let the excess fuel evaporate, so wait as long as you can, and then try to start the engine while holding the gas pedal to the floor — but be careful NOT to pump it. Pumping the pedal might be what got you in this predicament to begin with.
You hear a popping sound coming from under your hood, and now it it feels like your engine is hesitating. Which of these might be the problem?
When your car feels sluggish and you can hear popping from under the hood, it could be lots of things, among them: dirty or damaged spark plugs (and their wires), a clogged fuel filter, other ignition problems, or trouble with the car's catalytic converter.
Thick black smoke coming from your car's exhaust pipe is usually alarming. What might cause that?
Black smoke coming from a car's exhaust pipe can happen because the engine is flooded with gasoline, typically by damaged fuel injectors and sensors. Black smoke can also mean a problem with your car's air filter, too.
What is white smoke coming out of the exhaust pipe a symptom of?
On a cold morning you may notice white vapor coming from your exhaust pipe. It's normal and stops as soon as your car warms up — probably no longer than 20 minutes. But if it's white smoke coming from your car's exhaust pipe, that can be caused by all of these problems.
What kind of fluid leak could cause the color of your car's exhaust to turn blue?
Blue smoke indicates there's a problem with leaking and burning oil.
Why might it smell sweet in the passenger compartment of your car?
A sweet, steamy smell inside your car indicates a coolant problem, for any number of reasons, most of which point to the engine overheating.
Which is NOT a sign that your car's engine has a worn piston ring?
Excessive oil consumption as well as poor performance and loss of power are all common symptoms of worn piston rings.
Which piston problem sounds almost like a bell?
"Piston slap," the sound a piston makes when it rocks back and forth inside a cylinder, sounds a lot like a bell.
The mass air flow sensor (MAF) measures the air flowing into the engine, and it figures out how much fuel needs to be injected. How would you know if it's malfunctioning?
You'll know your car's MAF is bad because it can decrease your car's fuel economy by as much as 25 percent. Ouch.
What 's that green or orange sweet-smelling fluid creating a spot under your car?
Ethylene glycol antifreeze is that green, orange or yellow sweet-smelling fluid. The first symptom of a leak? If you don't notice the indicator lamp, you will notice when your car's engine overheats. Antifreeze is lethal but tasty to cats, dogs and other animals, so be sure to clean up these puddles as much as possible.
What happens if you accidentally put diesel fuel into a car with a gasoline-powered engine, and then drive home?
Diesel is thicker than gasoline, which means as soon as you started the car, the diesel went to work clogging your gasoline-powered engine's fuel injectors, filters and lines. If your car makes it home and continues to start, you'll feel timing and performance problems before the engine finally gives up the ghost.
You turn your car off, but it continues running. It's not possessed. But why would that happen?
Also called "run-on," this mostly happens when you fill up with the wrong octane gas for your car. Both a failing solenoid or an overactive carburetor could also cause the problem.
What is your car's engine lacking if it is surging at highway speeds?
If your engine is surging, it's a sign that it's not getting the right fuel mix or enough of it.
Hearing dinner sizzle on the grill is far better than hearing a sizzle under your car's hood. What does it mean if you hear your car's engine sizzling or hissing right after you turn it off?
Sizzling indicates there's a fluid — engine oil or antifreeze — leaking onto something hot, like the exhaust manifold.
Knock. Knock. Your engine doesn't want to come in, but it does have something to tell you. What is engine knocking/pinging a sign of?
There are a few reasons, and degrees of severity, for your engine to start pinging or knocking at you. It happens because of a problem with the air-fuel mixture, and could mean any of the following: You need to use a different fuel octane, there may be carbon buildup, or the spark plugs need replacement. Left unfixed, it can do some serious engine damage.
What could be wrong if your car's gas mileage has been poor lately, and now it's stalling?
Poor gas mileage and stalling, as well as rough idling and/or a hissing sound from under the hood, can be symptoms of an engine vacuum leak.
What's causing the clicking noise that gets louder when you rev your engine, but then disappears at higher speeds?
Clicking noise, also called "chatter," is the sound of your car's valve train, specifically defective hydraulic valve lifters (also known as hydraulic tappets).
The check engine/malfunction indicator light could come on on any number of reasons. What's NOT usually one of them?
The check engine light, also known as the malfunction indicator light, will trigger for a lot of things, including a bad catalytic converter, dirty air flow sensor or even a loose gas cap. But if you forget to change your oil, it won't give you reminders before the damage is done.
What controls your car's performance and drivability, like the engine spark and fuel efficiency?
The engine control module (ECM), also known as the engine control unit (ECU) or powertrain control module (PCM), handles the engine's performance.
Which is the worst-case scenario for why your car has low oil pressure?
First, check that your oil level isn't low. Not the problem? It could be oil pressure. If that's not about 10 PSI for every 1,000 RPMs of engine speed, it could be a bad oil pump, in which case the oil-pressure sending unit could be on the fritz. But the worst scenario is worn engine bearings, which means your engine will need to be either rebuilt or replaced.
You're idling at a red light when you hear what sounds like a metallic double knock. What part of the engine could cause that noise?
Faulty piston pins cause engine noise, but it's a really specific type of 'secret knock': a metallic-sounding double knock, usually most noticeable at idle.
Which is NOT one of the three most common engine problems?
The most common three engine problems: It won't start, it overheats, or the "service engine soon" light comes on.
The check engine light shouldn't stay on for more than a few seconds after you start your car. What should you do if it starts flashing?
A flashing check engine light means the problem is more serious than a loose gas cap. Check for signs that your car's engine is misfiring, a serious problem that could cause damage to the catalytic converter.
Which is not a reason for a car's engine to seize?
Your car's engine may seize if there's a lack of oil, if there's rust accumulation, and if there's a mechanical issue like a loose piston that's become lodged.
