Harper - Reinstate Monica
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Can I leave my car sitting outside for about 5 years?
78 votes

I've done it. I don't recommend it, unless the car has exceptional sentimental value or is especially equipped for an unusual job. Sell it on Craigslist or better method, and then, buy another one ...

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Is revving the engine to redline on idle at morning bad?
54 votes

If your engine even has a problem carboning up, you don't clear it at cold start. Nor do you clear it by spinning the engine to redline. "Revving" isn't meaningful to diesel engine performance the ...

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Can salt water be used in place of antifreeze?
29 votes

Terrible idea. The salt will precipitate and block the radiator fins Of course you know you can dissolve things like salt into water. You probably also know there's a limit to how much it can hold - ...

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Why does a catalytic converter have to connect to the engine electronically?
22 votes

It is not a simple filtration system. It is, as the name implies, a catalyst system. In order to work properly, the catalyst must be maintained in the correct condition, which means, being fed the ...

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How slow ( not zero) can a car engine run without hurting engine and saving on fuel
Accepted answer
20 votes

The oil problem You can run any engine speed you want as long as you keep the oil pressure up. Because of the impossibility of getting a roller bearing down a crankshaft, engine bearings are "...

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Is it okay or useful to run heat and AC at the same time?
Accepted answer
17 votes

You're meant to. In fact, in older cars, it was automatic when redirecting air to the window defroster. On this GM control, the far right position would activate the A/C compressor. Almost always, ...

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Does kicking a tire off your car from underneath it while it's held up by a stable jack pose safety threats?
14 votes

Even if you had supported the car properly with jack stands, it was still a huge mistake to kick it or exert force on it. Even jack stands are not so stable that they can handle a lot of dynamic side-...

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Car won't start after sitting for 2 years even with a jump. Is it a starter or alternator issue?
13 votes

It's the battery Starting an engine takes a much larger energy impulse than jumper cables can deliver directly through their typically-thin wires and the small surface area of their alligator clamps. ...

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Is it possible for a vehicle to be manufactured without a catalytic converter?
13 votes

Yes, in theory. The government doesn't care how your engine hits the required emissions numbers. As an engine designer, you get a tabula rasa, and are free to build any system that will do the job. ...

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Why do mechanics give the wheels a spin after raising a car for inspection?
12 votes

What exactly are they looking for? Anything that could be wrong or irregular. Tire defects Bent wheel rims Worn bearings noisy anything dragging brakes health of differential gears condition of CV ...

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RPMs too high on freeway?
12 votes

That is the excellent Mazda B3 engine. It will give you 300k service if you treat it nicely. It loves to rev. It does not like to lug. If you are at high power at low RPM (e.g. an RPM that feels ...

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Why don't we rotate tyres but you rotate tires?
12 votes

You always fit the best tires on the rear. Why? They don't motor*, don't steer and barely brake - why can't rear wheels just be casters? The rear tires are your rudder They keep your car from ...

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Two-stroke vs four-stroke design
Accepted answer
9 votes

Depends. A key point of 2-cycle engines is that a thing called scavenging happens with the piston at the bottom: at the end of the power cycle/ beginning of the compression cycle. During ...

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Maintenance tips to prolong engine lifespan for short trips
8 votes

If you are filled with the "urge to do something", I could give you some placebo task that does nothing but makes you feel like you're being diligent. But that's silly. This service is not that big a ...

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Are car batteries meant to be disposable or are they re-chargeable?
7 votes

Lead-acid batteries are rechargeable. Have you tried recharging it? That often will do. Lead-acid batteries fail after 4-7 years The simplest reason is there's acid in them. But some other ...

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"Iron wires" showing through sidewall
6 votes

Sidewall damage is almost unrepairable. If it is indeed damage to the steel belts, the tire will fail violently (instantly) soon in the future. That's a good reason not to be trying to change it ...

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Where does the power in an idling engine go?
6 votes

Get in your machine shop and devise a hand crank for your car's engine. Crank that baby over. Note that it's fairly difficult to crank over, even at 20-30 RPM. Now devise a "gear-up" device that ...

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How can I prevent the backup camera from turning off in a Volkswagen Passat 2014 when going backward at over ~30 km/h?
5 votes

Your root problem is a cognitive bias. It's really difficult to understand "safety" when accidents happen rarely. All minds are hardwired to learn about things by direct experience. So when ...

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When jumpstarting a car from another car can one connect the chassis of one car to the chassis of the other car?
5 votes

Car batteries are extremely well-connected to chassis Almost all cars use the chassis of the car as the (negative) ground. Chassis is extremely well bonded to the battery negative terminal, since this ...

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How do cars drive through deep water as shown on many videos online?
5 votes

Later, they will sell the car to a sucker And that poor sucker will have constant electrical problems, which cost them thousands in attempted repairs, and ultimately lead to scrapping of the car. ...

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I put E85 gasoline into my non-flex-fuel car
Accepted answer
4 votes

Probably not, but you've confused the poor computer, because the fuel doesn't have nearly the energy content it is expecting. Your best bet is probably to get some proper gasoline cans, siphon off ...

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Seized engine due to being run without oil
4 votes

The critical bearings in your car are plain bearings, because it's super hard to push a roller bearing over a crank eccentric. (Might be possible with camshafts). Plain bearings are amazing, ...

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Aftermarket seats
4 votes

OEM seats, e.g. From a wrecking yard, could work... but this is a bit tricky. Seats will definitely swap between your same model and year, so if there is an up-level trim version of the seat, that ...

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What's the difference between 2 A and 10 A charging options?
4 votes

TLDR: use 2A when unattended. An ideal battery charger does 3-stage charging based on the battery voltage - to quickly charge in the midrange, taper the charge near full, and then trickle at the ...

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Getting Stale Gas Out of a Gas Tank w/out Dropping the Tank
4 votes

Just dilute it 3 year old gas? Don't worry about it. Drain it as far as possible, then just dilute it by filling the tank with new gas. It'll be fine. If you're really that, that worried about ...

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Does the mileage indicate the quality of the gas?
4 votes

"miles remaining" is an guesstimate based on your recent driving The system has stores a great deal of data about your past driving performance, and the "miles to E" is assuming you will continue ...

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Simplest installation of car-powered car-pc
3 votes

Electronic modules that take car 12V and make 5V are sold at every convenience store, gas station and grocery store in the developed world. Right next to the phone charging cables. They're not even ...

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Using an Anderson plug to jump start a vehicle
3 votes

Tow trucks use Anderson SB series connectors, typically the larger SB350, gray to connote 12V DC. Look up the current ratings for that beast. Note the listed hot-plug amperage, so yes, yanking it hot ...

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Dealership says European cars need rotors replaced with every pad change because they use softer metals in rotors
2 votes

That's not decided by the dealer, it's decided by the "last turn" figure in the spec on the rotor. If the machinist determines that turning it down to a clean surface will result in rotor ...

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Does drilling a hole in thermostat affect engine temperature during cruising speed? (Please read my explanations before answering)
2 votes

Waste of time. Air can already leak through the thermostat. Thermostats are baffles, not seals. The difference is a seal prevents all flow, a baffle only prevents significant flow. Baffles are used ...

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