spark plugs are used to ignite the fuel-air mixture in a petrol/gasoline engine.

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9answers
228k views

What is the difference between normal, platinum, iridium plugs?

What is the difference (besides price) between normal, platinum, and iridium spark plugs?
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11answers
157k views

What happens if a single spark plug unexpectedly goes down in a multi-cylinder engine?

AFAIK vehicle manuals say owner must replace spark plugs every N miles. Suppose he fails to do so and a single spark plug unexpectedly dies in an engine with multiple cylinders right in a freeway. ...
18
votes
1answer
5k views

How do I know when to change my spark plug

I ride a Piaggio scooter with a single cylinder engine. Recently I broke down and the engine wouldn't restart. It turned out the spark plug was stuffed. How can I ensure that doesn't happen again?
13
votes
2answers
15k views

How much does spark plug gap affect fuel efficiency?

I've read conflicting reports regarding how plug gap can affect fuel efficiency. For example, I've read that too small a gap won't cause a clean burn, or that too large a gap can cause misfires due ...
12
votes
5answers
3k views

How to properly change out spark plugs?

I am looking into how to change out my spark plugs on my 4 cylinder 2005 Mazda 3. All I know to do is: 1: Open each cylinder. 2: Use a spark plug socket (with the rubber insert) to remove the old ...
12
votes
2answers
2k views

Is there a measurable benefit to replacing spark plug wires?

My 92 Civic has very old spark plug wires, probably original, but their resistance is in-spec (under 20k ohms), they have no external damage, and the vehicle has no misfire or other symptoms ...
9
votes
1answer
72 views

Where do spark plugs get their electricity?

Where is the electric charge coming from and does it have a large amount of electric charge to it?
9
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2answers
205 views

Firing a Coil on Plug

I was wondering if there is a simple way of firing a coil on plug outside of the car. The coil in question is just a two wire coil on plug and I don't know if its possible to just hook up a 12V ...
9
votes
1answer
55 views

Ford F150 broken spark plug removal

I have a friend that has a 2003 F150 V8 3 valve V8 motor, when he went to change the spark plugs some of them broke off. How do you remove the part that is still in the head? Here is what a new one ...
8
votes
3answers
6k views

2000 Honda Civic Won't Start after Replacing spark Plugs

My 2000 honda civic ex 4-dr sedan seemed like it was misfiring. I decided to check the spark plugs to see if that was the issue. I replaced the spark plugs. The car would turn over however the ...
8
votes
2answers
88 views

Why are the spark plugs from the same 2 cylinders corroding faster than the others?

On my engine ('99, 360 v8 Magnum), I replaced the spark plugs less than 15k miles ago, because of misfires in cylinders 2 and 8. Those two plugs were badly corroded. Today I had to replace them again, ...
8
votes
1answer
287 views

What can I do with an Inline Spark Tester?

Due to my recent problem with weakly firing plugs, I'm looking at inline spark testers. I've seen three basic types: The simple flashing one which goes in between the wire and plug with the plug in ...
8
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2answers
232 views

Follow up question on spark plug heat range

@vini_i gave a great answer to my previous question here (What is spark plug heat range) Part of that answer is that the reason for spark plugs having different heat ranges is that if it runs to ...
8
votes
1answer
62 views

How to check if spark plugs are firing? Coil-on plugs

While trying to diagnose a tricky car not starting problem I was asked to check if the spark plugs were firing at all. I've found plenty of resources on inspecting the condition of spark plugs after ...
8
votes
1answer
1k views

What do i need to know when replacing a valve cover gasket

I have an oil leak from a cracked valve cover gasket that i want to replace myself. I bought the gasket nearly 6 months ago and i am apprehensive at doing it myself without sort of feed back as to ...
7
votes
1answer
64 views

What is the effect of different spark plug electrode tip diameters?

When choosing spark plugs one has a lot of options. One of the differences is the diameter of the electrode tip - some spark plugs have a large flat tip, and newer models often have a really thin tip. ...
7
votes
1answer
3k views

What does a healthy spark plug look like?

The spark plug pictured here: Has some black carbon on the underside of the ground electrode and has black carbon on the "base" area below the centre electrode (not pictured). Is this normal and ...
7
votes
2answers
56 views

How to diagnose the cause of no power reaching the spark plugs when power reaches everything else, after checking fuses?

I've been trying to get my long-suffering Toyota RAV4 first generation (1998) to start after numerous different problems, the latest of which I've narrowed to the spark plugs not firing seemingly due ...
6
votes
1answer
88 views

What is spark plug heat range

I was watching a show and their project was adding a bolt on turbo kit. In the process they mentioned that they needed a colder spark plug. What does a hot or cold spark plug mean? What changes ...
6
votes
1answer
548 views

Two-stroke dirt bike piston running into spark plug

Recently, I submitted a post on here regarding a broken ground electrode on the spark plug of my 2005 Suzuki RM125: Bottom piece of spark plug broke off in motorcycle engine Well, I found out what ...
6
votes
1answer
112 views

High revs after changing spark plugs

I have an '07 Chrysler Town & Country. Check Engine Light came on 2 weeks ago, ran the diagnostics : Misfire in cylinder 3. So we changed the spark plug in that cylinder to see if that was the ...
6
votes
3answers
1k views

Estimate for head removal / reinstall

In changing the spark plugs in my 2000 Ford Mustang GT (4.6L), I sheared one of them (number 3) The ceramic is totally removed, as is the hex nut. The threaded portion as well as the ground electrode ...
6
votes
1answer
77 views

How long would pouring a little oil into a spark plug well take to stop a car starting?

I realise this is a strange looking question! I'm in a country where many local mechanics unfortunately have a bad reputation for creating small problems while fixing other problems in order to get ...
6
votes
1answer
81 views

Socket wrench turns loose on top of spark plug

I'm trying to replace the spark plugs of my 2006 Prius, but the deep well 5/8 socket attached to a 2 in extender just turns loose, as if it does not fit in the top of the spark plug. I tried also 3/4 ...
6
votes
2answers
3k views

Really high idle after tightening spark plugs

I had a very nasty tick in my engine after doing a bunch of work to it, I just redid my chain tensioner which went a long way to fixing it, then I found that spark plugs could cause a tick, so I ...
5
votes
2answers
781 views

How can I adjust gaps to spark plugs?

Have a couple spark plugs that needs adjusting. Whats the best practise for this? Is this valid? http://motorqa.com/question/8/whats-the-best-way-to-adjust-gap-in-spark-plugs
5
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3answers
6k views

Are Oil Puddles in Cylinder Head Normal?

Changing spark plugs and one well was full of oil. I took off the valve cover to replace the gasket and noticed that there was quite a bit of oil puddled in the cylinder head. Is this normal or could ...
5
votes
2answers
77 views

Is it necessary to replace functioning spark plugs?

I have a 2000 Mazda Protege that last had it's spark plugs replaced about 4-6 years ago (about 40k-60k miles). It's a commuter car, but it's a short commute and mild driving conditions; probably 85% ...
5
votes
2answers
776 views

Will Driving 100 Miles With a Misfire Damage My Car?

Background: I have a 2002 Dodge Dakota Quad Cab slt with 4.7L Magnum V8. My check engine light came on when I was at work. I then drove 20 miles home to my house, pulled out my scan tool and ...
5
votes
2answers
111 views

Very slight arcing of good spark plug wires

While looking for the reason of occasional misfires I checked if my spark plug wires are arcing at night. There was no textbook arcing with popping sounds and pretty lights, but there was extremely ...
5
votes
1answer
11k views

How to diagnose a bad spark plug?

What I always did up to now to check if my spark plug was doing fire : Remove it. Keep it plugged into the spark plug cable. Ground it on the frame. Start and check if sparks happen. If they are ...
5
votes
1answer
368 views

Honda CBR 250 won't start after heavy rains, puttering noise

There has been heavy rain and yesterday I couldn't start my bike. The main and other fuses are not blown. I ride it regularly. Turning the bike on: https://vid.me/pYNw. The high-pitch noise is not ...
5
votes
1answer
16 views

2008 Grand Prix GPX

What spark plug should I be using? I did my own tune up and the guy at auto advance told me to get some Bosch spark plugs for my car but then I notice less power. A mechanic told me I shouldn't have ...
5
votes
2answers
421 views

How often should spark plug wires be replaced?

I last replaced them with the plugs about 4 years/60-70k miles ago. I bought platinum plugs I if I remember correctly, so I still got some life on those. The car (2001 Buick Regal) is still in good ...
5
votes
2answers
5k views

Spark plug gaps - manufacturer or shop manual?

So I have a 2000 Ford Ranger XLT 4.0L V6 OHV Engine and I recently replaced the spark plugs. The thing is, the original recommended spark plugs have a gap of 0.52-0.56, which is what is recommended in ...
5
votes
1answer
28 views

2000 Buick Century not running after spark plug change

I had someone come look at my car (big mistake I should have done I it myself). He said the spark plugs needed to be changed and while he was changing them he was revving the engine. He didn't put the ...
5
votes
2answers
311 views

RPM drop when coming to a stop in neutral, Civic 06

Let's say I'm getting off the freeway, I press the clutch, shift out of 5th to neutral. At that moment my Civic DX would usually drop to about 1000 rpm at idle. For the past month it drops too low, ...
5
votes
1answer
1k views

No spark on my new motorcycle

I recently purchased an 81 Suzuki GS450L, my very first bike. I'm not getting a spark. When it dies, it does so silently. No backfire, sputtering, etc. My first thought was that it had aftermarket ...
4
votes
4answers
36k views

What is the proper way to extract a broken sparkplug?

When dealing with a car with aluminum head(s), what is the proper way to extract a broken sparkplug?
4
votes
1answer
129 views

Do I Need to Ground the Spark Plug When Testing

When I'm using a known good spark plug to test spark at each wire, do I need to ground the threads of the plug to the engine block like the guy in this video is doing? What happens if I don't ground ...
4
votes
2answers
80 views

any downsides to early spark plug changes?

Are there any downsides to early spark plug changes? some say 10k 15k etc and some do it as early as 5k =S but would it be okay to get into the habit of changing them after each oil change (6k) miles ...
4
votes
1answer
13k views

Getting a stuck spark plug out

4 spark plugs--three finally changed but one won't come out and is apparently stuck with a deposit of carbon. Has a service every year so not as though it is ignored. we don't want to change the car ...
4
votes
1answer
539 views

When I remove a spark plug is it bad news if dirt or grime falls into the engine

Despite my best effort to clean up a corroded spark plug and blowing the area with an airline before removing would it be bad news if dirt or grime falls into the engine in the process of removing it? ...
4
votes
1answer
88 views

Gapping New Spark Plugs from the Dealership

In general, if I buy plugs from a dealership which looks up which plugs I need based on my cars VIN or license number, do I need to worry about checking the plugs gap, or can I just assume they will ...
4
votes
2answers
1k views

Spark Plugs 1998 Buick Lesabre

Where are the spark plugs in a 1998 Buick Lesabre? Pictures would be helpful as I'm a novice at this type of thing. I'm assuming I need all six because I'm getting a check engine light saying number 6 ...
4
votes
1answer
59 views

Vespa Plug,Contact Point and Condenser

For my Vespa P150 x I want to know technically regarding to Plug What should be the color of a healthy plug spark? Mine is a blue red like color. Contact Points How can I check that the points of ...
4
votes
1answer
75 views

How to check if bad spark plug threads are causing compression loss

How do you check if your spark plug threads are bad? I would like to know the most non-invasive method of checking this and also the most cheapest way to check this.
4
votes
2answers
9k views

Oil leaking from spark plug socket

I have oil leaking from a spark plug socket on my 1981 Volkswagen Rabbit pickup truck. Before you ask, it's swapped with the 1.6 gas motor instead of the 1.6 diesel. The oil leak appears to only be ...
4
votes
4answers
2k views

How to remove a stripped/broken sparkplug on a 2001 Chevy Malibu

I have tried to remove the #3 spark plug from my 2001 Malibu, with no results. It is very hard to get to that particular spark plug because there is not much room between the fire wall and cylinder. I ...
4
votes
1answer
130 views

Carbon Fouled Plugs '74 TX500

I'm somewhat new to wrenching my bikes and I'm loving it! :D I have a 74 Yamaha TX 500 that keeps carbon fouling her plugs :(. I've put on slightly hotter plugs (D7EA from D8EA), narrowed the jets ...