General internal combustion engine questions.

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16
votes
3answers
5k views

Static vs. Effective compression: Why does higher effective compression not require higher octane gas?

Background I've been trying to do a lot of research on boost lately because I'm planning on running a moderate turbo setup on my daily/light-duty-autox car in the future. I'm trying to get into the ...
6
votes
2answers
4k views

Lugging the Engine (Manual Transmission)

So...lugging the engine obviously isn't something that is good. But why? For example when you feather a clutch to get the car moving, it lugs for a quick moment when you hit the catch point (When ...
5
votes
3answers
12k views

Engine power specification at different rpm?

Car companies advertise power of an engine at different rpms. Car 1: 80 PS at 6000 rpm Car 2: 85 PS at 6500 rpm What does the power at different rpm mean? Does it mean Car 1 has better power than ...
6
votes
4answers
20k views

Is engine braking harmful? [duplicate]

Possible Duplicate: Does Downshifting (Engine Braking) Cause Extra Wear and Tear? My wife and I have a disagreement about a practice of mine--engine braking. When I'm driving her manual ...
2
votes
2answers
802 views

Mazda 323: Plugged in Coolant Temp Sensor - Now Car won't Start

I recently bought a Manual 97 Mazda Lantis 323 1.8L DOHC 16 Valve BP. I found the following wire unplugged on the drivers side of the engine, next to the water intake from the radiator: It plugs ...
8
votes
3answers
6k views

How to begin learning engine tuning?

Quite simply, I want to begin tuning and modifying automotive engines for hobby. I have always been fascinated with cars, and I want to become knowledgeable in as many aspects of car tuning as ...
15
votes
7answers
63k views

Is idling bad for your engine?

If I sit in my car for 30-40 minutes with the AC and the car idling, does that "hurt" the engine, or does it simply waste gas and pollute the air? Would it be better if I turned off the car? A ...
6
votes
2answers
13k views

Engine Size and Fuel Consumption

I have this weird misconception that the engine size is related to the amount of fuel being burned in one cycle(4-stroke engine). I know this is stupid but how does engine size relate to the amount of ...
5
votes
2answers
25k views

Oil in coolant - how much trouble am I in?

I have oil in my coolant reservoir. Could it just be the head gasket or is it almost certainly the entire engine or might it be something else entirely? Thanks in advance...
23
votes
9answers
33k views

Is it necessary to 'burn in' or 'break in' a new car?

I've just bought a new 2011 plate car. I've heard stories of people 'burning in' engines for the first few hundred or couple thousand miles using methods such as: Not driving above 50 mph. Varying ...
14
votes
2answers
8k views

Why doesn't the engine stall out when you come to a stop with an automatic transmission?

When you come to a stop with a manual transmission you have to push the clutch in or take it out of gear to keep the engine from stalling out. What keeps the engine from stalling in an automatic ...
6
votes
2answers
8k views

Oil pan threads stripped?

EDIT Helpful links on how threads got stripped and by who: http://tl.acurazine.com/forums/showthread.php?t=878261 Seems to be a common problem with some shops, where they don't take good care. ...
15
votes
2answers
20k views

Is starting your car with the A/C on bad?

I was always yelled at by my father when I was first starting to drive when I left the A/C on when I turned off the car, and then later turned it back on, with the reasoning that I was ruining / ...
9
votes
4answers
25k views

Why does a Turbocharger only produce boost when the engine is under load

As per the Title. Why does a turbocharged car only produce significant boost whilst the engine is under load. Is is something to do with how much exhaust is being produced or is there some kind of ...
7
votes
1answer
844 views

Car Suddenly Decides To Not Crank

Today I turned the key to start up my car and all the lights (headlights and instrument panel) came on bright and normal, but the engine made absolutely no sound. It wouldn't start, it didn't even try ...
5
votes
2answers
76 views

Water leaking into frame case/engine?

I just had my 2012 Mini Cooper S (66K miles) repaired last week last week for a failed/leaky water pump. My car had an episode where it overheated and shut down and wouldn't start after pulling over ...
5
votes
1answer
96 views

Acceptable amount of slack in a timing chain with high mileage?

1995 Chevy S-10 Blazer - 4.3 L Vortec V6 (vin W with PCM) - 230,000 miles original owner. FWIW, this model car/engine does not have timing chain inspection and/or changing as part of the routine ...
5
votes
5answers
11k views

What is the purpose of plastic engine covers?

I have a 2010 Toyota Corolla. What is the purpose of the large plastic cover that stretches over my valve cover? Does it have a particular function? Are they just for looks? Or are they designed by ...
1
vote
3answers
375 views

My 2001 Mitsubishi Airtrek revs at 2250rpm for 30 seconds before slowing. Will this speed harm the engine?

My 2001 Mitsubishi Airtrek 2wd with 86000k revs at 2250rpm for 30 seconds before slowing. Will this speed harm the engine?
7
votes
1answer
346 views

Why does an engine's idle RPMs take time to settle from a cold start?

I've noticed my car's (healthy) engine will idle at a slightly higher RPM for a few moments after it's been started from cold/not run for a day. I also noticed that my (somewhat less healthy) other ...
4
votes
2answers
1k views

Dealership Installed “Oversized” Oil Drain Plug As Solution

In this question, we discuss stripped oil pan threads. I learned it is a result of user error - over tightening and cross threading, by the dealership I consistently go to. Many people have come ...
8
votes
2answers
9k views

How much power (HP) do the components on the engine belt generally use?

In general, how much power (HP) to the components on the the engine belt actually use? I'm trying to come up with an estimate of how much horsepower an engine wastes on things like the AC compressor, ...
7
votes
2answers
6k views

WHY does an engine stall? (manual transmission)

Before you write off my question as one that's been answered a million times already, I want to clarify. I understand that the engine needs to go a certain rpm and when you try to engage the clutch ...
6
votes
1answer
1k 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 ...
4
votes
3answers
3k 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, ...
3
votes
2answers
2k views

Gas pedal not responding

It just doesn't work, as if I weren't even pressing it and it happens regardless of the speed. I have to turn the engine off and on again and it'll work for another 3 or even up to 20 minutes ...
2
votes
3answers
3k views

92 Civic engine won't start after replacing head gasket

I just replaced the head gasket in my 1992 Civic. Started it up before putting everything back together (just a second since it had no coolant, exhaust wasn't connected, etc.) and it ran fine. But now ...
2
votes
3answers
306 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 ...
12
votes
1answer
152 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 ...
8
votes
1answer
858 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?
7
votes
4answers
659 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 ...
7
votes
4answers
57k views

Cold start squeaking noise in engine

I just purchased a used 2010 Corolla 3 days ago. I've only now noticed that when I start the car, there is a squeaking sound coming from the engine. It lasts no more than a second. Sounds like it ...
6
votes
5answers
10k views

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

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. ...
6
votes
4answers
2k 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 ...
5
votes
1answer
39 views

Reliability of water test for valve seal

I took my valves out, cleaned and lapped them and put them back together. I also put new valve stem seals. At least on one side of my V6 Tacoma. I performed several water tests to check the seal of ...
5
votes
1answer
49 views

Rebuild for longevity

So, I have a question about a 98 2.0 rt neon. I am going to get a top/bottom rebuild on it, the block has 260000 km on it. I have seen rebuild kits on the market anywhere from 300 dollars (ebay ...
4
votes
2answers
391 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?
4
votes
1answer
556 views

Astra Turbo sounding like a diesel

http://www.youtube.com/watch?v=ph6JOhFJcJA The video above demonstrates the sound I hear when my car is at operating temperature. I don't know why it would sound so rough. It doesn't sound quite as ...
4
votes
1answer
473 views

2001 Pontiac Grand Am SE oil in the coolant

Recently my car started chugging and "vibrating" at low speeds, and the check engine light is flashing on and off. On inspection, I found oil in the coolant. I don't know a lot about cars, but a ...
4
votes
1answer
2k views

Car Stalls When Coming to a Stop

Make: Chevy Model: Cavalier (4 cyl.) Automatic Year: 1993 Miles: 230K Normally my Cavalier drives just fine without problems. However, if I drive for 45+ minutes then it will sputter and stall out ...
4
votes
2answers
5k views

Engine never warms up (actually: it cools down) at highway speeds

I have a 1997 Caravan (base model) and normally on my drive to work and my highway drives in rush-hour, the engine warms up just fine. I took a road trip for work, about an hour and fifteen minutes ...
4
votes
2answers
854 views

Forced induction and engine braking

So does forced induction negate the effect of engine braking on compression motors? For example, going down an incline, drop into 3rd (automatic) to get some engine braking going. With my new Chevy ...
4
votes
2answers
2k views

does a car normally continue moving at a constant speed when in gear and the foot is taken off the accelerator pedal?

I remember when driving a passenger car, when I took my foot off the accelerator pedal completely, but remained in gear, the car would normally continue to move at some low speed, different for each ...
3
votes
1answer
133 views

VW Golf 2001 Mk4 Diesel ASR Engine Problem

I've spent a crazy amount of money on my car lately and I still have the same problem. I've replaced the: Catalyst Converter Radiator Starter Motor EGR Valve Track Rod ends & Wheel Bearings ...
3
votes
1answer
65 views

Should I care about valve order or are they interchangeable?

So I've just learned how to take valves down and I'm pretty fascinated by the whole mechanism. I got a C-clamp compressor and took two valves out just to try. Went smooth. A question: is it important ...
3
votes
1answer
66 views

What is a stress riser?

What is a stress riser and why is it important to avoid them during engine construction or rebuild?
3
votes
2answers
1k views

What exactly is Honda's i-VTEC technology

I see that almost all of Honda's cars have an "i-VTEC" logo at the back. I googled it and came to know that it has something to do with different cam profiles. Can someone explain? A diagram or ...
3
votes
2answers
331 views

What happens to a car engine when giving max throttle while not in gear

I was driving (well standing still actually) during rush hour, and I was suddenly wondering what would happen to a car engine when I would push the accelerator pedal all the way down while the engine ...
3
votes
1answer
232 views

Bottom piece of spark plug broke off in motorcycle engine

I was riding my 2005 RM125 dirt bike the other day when it bogged down all of a sudden. I noticed the spark plug had backed out of the head, thus causing the stall. I pulled the spark plug all the way ...
3
votes
2answers
2k views

BMW 330D 2001 E46 Turbo Charger not working as expected after changing

I have a problem with my car. My car: BMW 330D, 135kw, 2001 year, E46. A week ago my turbo charger got broken when I was driving. There was a lot of white smoke going out of exhaust and there was ...