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What happens if you put wrong spark plugs into a car?

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If the thread is too long, combustion material will settle in the threads exposed and will strip the threads out of the head when removing the plugs
if the thread is too short , combustion material will fill up the threads in the head making it impossible to fit the correct plugs
if the thread is too long there is a possibility that the end of the plug will hit the piston top
you can have the correct length but some plugs have a taper seat to seal and others have a copper gasket
the plugs will not seat properly and will be difficult to keep tight or sealed off
if you mean by "wrong plugs" the wrong being different makes or numbers on the plugs there will be nothing wrong as all that matters is the thread size and length and seat seal

Posted on Jan 02, 2017


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Posted on Jan 02, 2017

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usually it will not start, It depends on how many wires are on the correct spark plugs.

Posted on May 23, 2011

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SOURCE: spark plug replacement wiring sequence for 1998 mazda millenia


1998 Mazda Millenia S 2.3 liter DOHC V-6


1998 Mazda Millenia L 2.5 liter DOHC V-6


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Posted on Dec 23, 2011

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SOURCE: how a engine works

sounds like the plugs where to long and the pistons hit them when you turned the engine over

Posted on Apr 29, 2012

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What causes a backfire

Gases in the engine exploding at the wrong time, Ignition timing set wrong, misfire putting un-burnt fuel into the exhaust system, then ignited by hot gases. Most common fault, is an ignition cross fire, where a spark plug is fired at the wrong time, happened mostly with high tension plug leads breaking down in damp conditions and shorting across each other, causing the plug to ignite gases in the cylinder at the wrong time when a engine valve is open.

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What happen if wrong matching spurk flug cable

If you put the wrong wire on a spark plug, the engine will not start, or if it does, will run very rough. It is ******* the engine. Get the correct firing sequence from a mechanic or a website and get the wires on the correct spark plugs.

If you are talking about the wrong cable type, I am not sure.

Nov 09, 2012 | Cars & Trucks

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How a engine works

sounds like the plugs where to long and the pistons hit them when you turned the engine over

Apr 28, 2012 | Cars & Trucks

1 Answer

1994 Toyota Corolla 1.6 Died the other morning and will not start. Has no spark at plugs! I have changed ignition coil, cap & rotor! Sill nothing! I found a 30 amp fuse labled CDS blown! Need to...

if you noticed no spark you must have maybe put the plug wires on wrong this happens you need to get the firing order and trace that down, make sure all wires are put in correct order, Is it turning over, you didn't say mayber more details would be good.

Aug 11, 2010 | 1994 Toyota Corolla

2 Answers

Rough(missing) when cold. Smooths out a little after warming up.

It is not unlikely a plug wire got put back on on the wrong plug. These cars will still run with a few plugs wrong.

May 29, 2010 | 1998 Subaru Impreza

2 Answers

I backed out of the drive way today and put it in drive and the car died. We can not get it started. It sounds like it's out of gas. It's turning over but not firing? It ran great last night.

is it out of gas?? if not after cranking over engine pull out a spark plug if
there is fuel it will be wet and smell of gasoline. next thing will be to determine if the vehicl has spark-put the plug into the plug wire place the plug onto the engine block (away from fuel sources) and have
some one crank over the engine breifly-note that you could get a shock
if the spark plug is not properly grounded (if this happens then you r doing it wrong). watch for spark across the electode. engine needs three basic needs-air fuel and spark with that it will ****,sqeeze, bang and blow....the four stokes of a 4cycle engine.

Apr 15, 2010 | 2001 Mitsubishi Eclipse

3 Answers

Rewired ford taurus spark plugs and when turns on it jumps what could i have done wrong?

If you replaced the distributor cap then there is a high possibility that you put the wires in the wrong firing order on cap.

If all you did was replaced the plugs, then I would pull each one out and recheck the Gap sizes with a feeler gauge. Also check to see if the spark/coil plug wires are touching metal or each other, which can cause the spark to arc out of the wire and never get to the spark plug. If I suspect an arc and do not see a physical problem, I wait until nighttime and look under the hood while engine is running...they stick out like a sore thumb. Also make sure that you did not put the wrong plugwire to the wrong spark plug.

When you change your plugs, you should also replace wires, cap and rotor.

Oct 17, 2009 | 2001 Ford Taurus

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