Questions tagged [engine]

Questions about vehicle engines. Most engines in road-going vehicles are 4-stroke internal-combustion gasoline or diesel engines.

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11
votes
1answer
627 views

What Can I Learn From Exhaust Manifold Temps?

I was wondering what I can learn from the temperatures on the individual exhaust pipes coming out of each cylinder. The question is general, and my specific example is on my 98 Mazda 626 GF 2L. Last ...
9
votes
5answers
50k views

Car dying at low RPM only after filling up with gas

My question is closely related to one about a Jag dying at low RPM, but is slightly different because it only occurs after refueling and because the problem persists after cleaning the throttle body, ...
9
votes
3answers
73k views

Does revving a car when cold make it warm up faster?

As winter comes along, I've always thought that revving the car would make it warm up faster, so the heating works better to clear the icy/steamed up windows. Does revving my car at idle to about 2-...
8
votes
5answers
33k views

Doing my own fuel induction service - how to, and how difficult?

I was recommended to get a fuel induction service for a 2002 V4 Camry, and am considering doing it MYSELF. The reasons for considering this are: My car idles a bit rough, especially when the AC is on....
8
votes
1answer
2k views

Electric water pump control

Electric fans are now common on cars, both aftermarket and stock. The advantages in horsepower, faster warmup, and hence emissions are well documented elsewhere. The same reasoning can be applied to ...
8
votes
5answers
81k views

What happens when you run out of fuel?

My question is specific to diesel or gasoline (petrol) engines. Many people told me that it is very bad to run out of diesel since it can damage the engine and it's difficult to re-engage it ...
8
votes
3answers
2k views

What exactly is a clutch?

I found out recently that the flywheel, driven by the crankshaft, is connected to (or part of) the clutch. I have a basic understanding of what a clutch does due to the fact that I know how to drive a ...
7
votes
3answers
5k views

Fiat Punto Wont Start. Fuel Light & Three warning lights flashing

My Fiat Punto 1.2 Year 2000 MK2 (I believe) will not start. The engine turns over but the car won't start. The fuel light is flashing and petrol gauge says empty which isn't the case. There are three ...
7
votes
3answers
222 views

What are some typical maintenance things that every owner should do regularily?

Right now I just get a car wash every month, and my oil changed and whatever is included in that. Usually just a quick "inspection". Is there anything else I should be doing for my car? Or also, is ...
7
votes
1answer
4k views

Heater smells like sulfur

I drive a 2006 Toyota Sienna. When driving with the heater on I often smell sulfur. This is more common when I am driving up a hill, but if I turn the heater off, the smell goes away. What causes this ...
7
votes
3answers
27k views

What are all the different types of fluid in a car and a short summary of their use?

A fluid is defined as anything that flows, hence for our purposes a gas or a liquid. I know that there is fuel, engine oil, engine coolant and brake fluid. Also air is normally taken in through a ...
6
votes
3answers
45k views

Overheating at idle - mechanic says head gasket

My car has been overheating at idle after a long period of time - perhaps 20-30 minutes in traffic. If I drive, it immediately starts to cool down again. I don't drive often so it hasn't been an issue ...
6
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1answer
10k views

Importance of engine compression ratio

Please explain the importance of Engine Compression Ratio. In Text books I could find the following importances Engine Cold starting Characteristics Torque Generated Fuel Consumption Noise Pollution....
6
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2answers
4k views

Royal Enfield Classic 350 - Motor Break-in Best Practice

How many km's should be driven with a lower speed to setup the bore for a Royal Enfield Classic 350, what is the minimum speed for that duration and how many km's should we maintain that lower speed?
5
votes
1answer
2k views

Why can a reasonably new car consume oil?

I have understood that the oil consumption between cars varies a lot, more than an order of magnitude. And by this I don't mean that a specific model of car consumes more oil than another model of car,...
5
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4answers
14k views

Ford Taurus common oil leak area?

On my last oil change, the technician noted some oil around top and side of the engine block and said there is a small leak. The only way to find where it is coming from is doing the whole dye test, ...
4
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2answers
2k views

Is it reasonable to charge the customer $1000+ to assemble the top of the engine?

I recently have an engine overheat issue and see my previous post for details: How long does items in the engine last in general for standard size cars? This is an interesting follow up on that at ...
4
votes
1answer
2k views

Do Compression Rings and Oil Ring Wear at the Same Rate?

Is it possible that the oil control rings might be worn to the point that you're burning significant amounts of oil, but the compression rings still be good? Or do they typically wear out together ...
3
votes
2answers
4k views

"tick-tick" sound in Enfield Clasic Motorcycle

BIKE ENFIELD CLASSIC 350 2013 Model ODOMETER: 14000 One and half year old Oil changed one and half month before general servicing. There is a particular sound from the engine while riding ...
3
votes
2answers
17k views

High-pitched squealing coming from engine

I've been told that a wet serpentine belt causes this. Is that true? If not, what else could it be? How can I fix this? This is a 2004 Chevy Trailblazer (4.2L 6-cyl. engine). I hear the noise ...
2
votes
3answers
370 views

Is my mechanic ripping me off?

My 2002 ford focus (built after may 23) died and the AAA and tow guy both said that it needs a new fuel pump. Anyway I went to the mechanic and he said it'll be 350 for the pump and 200 for labor. I ...
2
votes
1answer
6k views

How much force is needed to push a piston down? [closed]

Combustion from fuel and air is used to push a piston down. When they combustion it creates a lot of force, my question is how much force is needed to push the piston all the way down when the vehicle ...
33
votes
8answers
16k views

Why do manufacturers detune engines?

I was wondering why a manufacturer would detune an engine. An example -- there are many others -- is the Mercedes-Benz OM612 engine. Same engine, lower (peak) power output in the Sprinter than in the ...
21
votes
6answers
187k views

When is an engine flush a good idea?

I have heard really mixed opinions about the necessity of engine flushes. My quick research suggested that manufactures do not recommend doing them. In addition, I have heard of extreme cases of blown ...
21
votes
4answers
4k views

What are the benefits of a dry sump?

I've heard references to dry sumps, usually in reference to racing engines. But more recently I came across an article about a 'supercar' which stated that it had a dry sump. What are the benefits of ...
20
votes
6answers
7k views

What is regenerative braking and why don't we use it?

I know that many electric cars use regenerative braking to enable the car to become more efficient by converting what would otherwise be lost heat energy in to a more useful, reusable form of energy. ...
18
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4answers
5k views

What is the difference between a 180° V4 and a true boxer motor?

Reading this thread which talks about V4 motors, I am wondering what exactly is the difference between a 180° V4 motor you'd find in a Subaru and a true boxer (or horizontally opposed) flat 4 cylinder?...
18
votes
1answer
13k views

Why does diesel engine need a warm-up before the start-up?

When starting up, diesel engine needs approximately 5s before turning the key for ignition. Why is this neccessary and what can be damaged if you don't do that?
17
votes
3answers
5k views

Is my head gasket cracked?

My wife hit a large puddle of water in her 2006 Mazda 5. Until then it was running fine. The check engine light came on and car shut down and would not start again. Mazda says it is a head gasket. Is ...
13
votes
5answers
40k views

Why can some cars go through water while others can't?

Why can some cars (mostly old Russian cars on YouTube) seemingly go through water while others can't? I'm talking about situations when the water level is at half the height of the car, so the engine ...
12
votes
6answers
12k views

What happens if unsuitable oil is used in a vehicle engine?

I recently heard an urban legend-like story about a guy in a developing country who decided engine oil was too expensive and so used some vegetable oil instead. The story says the car ran for some ...
11
votes
7answers
24k views

Why did V4 engines never take off?

I read that Ford Taunus (not to be confused with Taurus, it was a small model for German market) used to be made with a V4 engine but that's about it. How come V4 never became more used in modern ...
11
votes
1answer
3k views

Brake Specific Fuel Consumption of 2-stroke vs 4-stroke

How much fuel do various types of engines burn per power output? I'm especially interested in naturally aspirated piston engines, and comparing two-stroke to four-stroke. The wikipedia article gives ...
10
votes
1answer
2k views

Scatter Camshafts - What are they and why do I want one?

It seems in the world on mini's as in Mini Cooper, there is a camshaft called a scatter cam. It changes the timing for cylinders 2 and 3. I've heard of changing the timing to have 1 and 4 firing at ...
9
votes
2answers
23k views

What are Performance Camshafts?

I read the following question recently: What is it about performance cams that make engines produce more power when they are installed? I know there are a few components for cars that have "cam" ...
8
votes
2answers
9k views

Starter Motor Intermittently will not engage

2003 Kia Pregio Diesel Van just purchased 1 week ago. Owner claimed no problems. Just did an oil change. Yesterday when I turned the key to start, the starter motor did not engage. No sound, I just ...
8
votes
2answers
4k views

Low power, bad gas mileage, smelly exhaust after engine work

My 92 Civic has had low power (need to use at least one gear lower than usual to get the same power) and has been getting bad gas mileage (15-25mpg vs 32-42 mpg usual) since I replaced the head gasket....
8
votes
2answers
110k views

Coolant/antifreeze leaking out of engine block (See photo/video)

I'm not sure exactly what is going on with my vehicle ('98 Wrangler, 4.0L), but it's pretty obvious something is wrong. I think I might have had some minor coolant leaking after the past few times I'...
8
votes
1answer
974 views

How do old cars actually lose horsepower?

I have heard that when a car gets old it slowly but surely loses its horsepower to some degree. For example, I used to drive a 1997 Ford Fiesta with a 1.25L 1242cc engine that supposedly produces a ...
8
votes
3answers
1k views

What are common cold weather starting issues with cars?

Based upon the current weather in parts of the Northern Hemisphere, I would imagine there are some people suffering from all manner of cold related vehicle issues. What are some of the leading issues ...
8
votes
1answer
2k views

Pneumatic Valve Spring Operation in Formula 1

In the 2006 Formula 1 World Championship the rules allowed for pneumatic valvesprings. These engines were required to have a 90° V8 engine with 2.4 liters of displacement, 4-valve-per cylinder layout ...
8
votes
1answer
5k views

How does Valve Overlap affect emissions?

In this question, it is suggested that valve overlap can affect emissions. In what way can valve overlap affect emissions?
7
votes
2answers
2k views

Are there any modern diesel engines that require electricity to continue running?

I was reading this question about an owner checking the alternator by disconnecting the battery, which is an easy way to validate on a gasoline engine. The single answer assumes that the OP is ...
7
votes
2answers
2k views

What exactly is meant by "engine coolant"?

I know that engine coolant is a fluid in the engine used to dissipate heat spots and keep the engine cool in general as the moving parts generate heat. In this context, I would call the oil an "engine ...
7
votes
6answers
15k views

Why do Diesel engines have a higher compression ratio than gasoline engines?

Are Diesel engines constructed differently, so that they have a higher stroke volume? (longer stroke, smaller combustion chamber etc.) I know the main differences between Diesel and Gasoline engines(...
7
votes
1answer
2k views

Overheat, coolant loss, P0170/P0117, hard start, smoke, delayed throttle, no vtec

So I'm on the road right now (or was, when I wrote this) having an issue that started a few days ago and I'm trying to diagnose it. I am not sure what info is relevant, it does feel like more than one ...
7
votes
5answers
59k views

How long should the engine be off until checking oil level?

I have seen contradictory advice for checking oil level on the dipstick. One advice is that the engine should be off for few minutes so that the oil has time to settle. The idea here is that the oil ...
7
votes
1answer
10k views

Cylinder Leak-down vs Compression Test

I understand that both cylinder leak down and compression tests are used to test for cylinder head, cracks, warps, and gasket leaks. I understand the difference between how each works: compression ...
6
votes
2answers
6k views

What does CC refer to when describing an engine?

I have been learning about various older cars on Wikipedia. I've always wondered what the "cc" refers to in the engine description. For example: 1964–1969 Porsche 911: 1991 cc 1965-1969 Porsche 912: ...
6
votes
1answer
2k views

What is the effect of the throttle body on the power curve produced by the engine?

I heard from another member of this community that the throttle body, among other things, has the ability to change the power curve of the engine. What exactly is a throttle body? How might the ...