Repair Topics / Spark Plug-1 / Spark Plug-2

• How to change spark plugs
• How to read spark plugs
• How to tune up your engine
• Why does my engine stall?
• Why does the engine stall after replacing the battery?
• Why is my engine running rough?
• Why does my engine have low power output?
• How to check compression
• How to retrieve trouble codes
• How to test engine vacuum
• How to test fuel delivery system
• Engine cranks but wont start
• Engine cranks excessively
• Engine stalls
• Engine vibration
• Engine has excessive smoke
• Engine has lean mixture codes
• Engine idles high
• Engine idles low
• Engine is making excessive noises
• Why does my engine hesitate?
• Car is making a clicking noise
• How to test a fuel injector

MORE: Engine spark plug questions

Question: 1996 Chrysler Lebaron mileage: 176,000.  My engine was recently re-built by specialists.  The engine, however, is fouling up plugs after less than 100 km.  The engine re-builders claim that the turbo needs to be re-built due to the increased load from the new engine.  The turbo worked fine prior to the breakdown.  What suggestions can you make re: the fouling of the plugs?

Answer: We are guessing that the piston rings in the rebuilt engine may not have seated yet allowing oil to foul the plugs.  It is possible that the oil is coming from the turbo.

Question: 1997 Dodge 1500 Ram mileage: 135,200.  As a part of preventive maintenance, I change my spark plug every 10,000 miles. I am using an ordinary plugs, my friend suggested to use BOSCH super 4 and also change my high-tension wire to 9 mm.  In this case, I can change my plugs after 50,000 and also boost the power up to 5%.  What is your recommendation?  Do you think it will not harm my engine if ever I will change?  Thanks.

Answer: We have found that it is a good practice to use the spark plug brand that originally came in your car when it was new.

Question: 1997 Mercury Tracer, mileage: 118,000.  Engine running on three cylinders.  When I remove, plugs the no. 3 spark plug end was burned off.  This happened twice in about 300 miles. 

Answer:  Check the fuel injector for the # 3 cylinder; it may be partially plugged causing a very lean mixture in that cylinder.  A lean mixture will burn extremely hot burning the end off the spark plug.

Question: 1997 Oldsmobile Cutlass Supreme mileage: 66,000.  When changing the spark plugs, is there a trick to reaching the back plug closest to the passenger side of the vehicle?  Any help would be grateful.

Answer:  First there is a motor mount pin that holds the engine further forward. Then with the engine cold, you just have to reach around the back of the motor.

Question:  1995 GMC Safari, mileage: 120,000.  I want to change the spark plug wires on my GMC safari.   I was told that I needed to know the firing order.  I need help!   What's the firing order?

Answer:  If you change the plug wires one at a time, it is not necessary to know the firing order.

Question: 2004 Toyota Tacoma mileage: 52,000.  I am replacing the spark plugs in my Toyota Tacoma.  The manual calls for twin ground electrode spark plugs.  The replacement from the charts says I can use Autolite 3924.  My question is--If I use the Autolite 3924, which is cheaper, will I hurt the car or its performance.

Answer:  The Autolite plugs will not hurt your engine, however, you will probably find the recommend OEM spark plugs will perform better.

Question: 1995 Geo Metro mileage: 107,000.  Thank you for your service; I have an important question regarding a "stuck" spark plug on a Geo Metro.  I recently had an alternator replaced on my Geo and the mechanic said he had replaced the sparkplug wires as it still was not running right.  He says that he was unable to remove one of the plugs so now the car is running on only 2 cylinders!  Of course, it runs very rough and has trouble starting in our cold Iowa weather.  I need your suggestions on how to remove this plug and replace it myself as he says it will cost about $300.  More to remove the head and remove the stuck spark plug!  I do not know if a Metro with that many miles is worth 600 to 700 dollars.   I have depended on this car for over four years and am sick thinking a plug could cost that much more.  Any Ideas to help me out?  I will be checking your web page for your response or you could mail me.  Thanks!

Answer: You need to find someone that can remove the old spark plug and if the threads are damaged, which they probably will be, a mechanic will be able to repair the strip threads in the head.  All this should be able to be done without removing the head.

Question:  2001 Ford Mustang,  mileage: 67,000   Could you please tell me the spark plug gaps for this car as I live in Scotland and it is hard to get info up here.

Answer:  Usually somewhere on the engine or in the engine compartment, there is a sticker with the engine specifications. The spark plug gap should be included.  If not .032 or an inch should be close.

Question: 1994 Ford Ranger, mileage: 60,000.  What is the spark plug gap for this engine?

Answer: Your spark plug gap should be .035.

Question: 2001 Dodge Ram 1500 mileage: 51,000.  The dodge dealer says that Split-Fire spark plugs are not to be used in Dodge trucks because the truck will run worse.

Answer: Use the spark plugs recommended by the factory.  It does make a difference.

Question: 1996 Isuzu Rodeo mileage: 100,000.  Only two of the four pistons appear to have an effect on the car.  I can pull the spark plug wires off the first and last plug and there does not seem to be any effect on the performance of the engine.  The engine does not smoke and there is spark to the plugs that apparently are not working?  Cannot figure out what is happening?  Any help will be appreciated.

Answer:  Try changing the plug wires on the cylinders not working, then do a compression check. If the compression is low but close to the same you may have head gasket that was failed between cylinders.

Question: 1996 Mercury Sable mileage: 120,000.  My car recently starts popping sound and stopping.  I have changed spark plugs, cables, and fuel filter but did not help.   Sounds like one of the cylinders is not working on idle speed.  When accelerate car is running well.  As soon as stop at the lights engine quits.  If I start the engine again, runs bumpy.  First, I noticed is spark plug on number three cylinder had oil on it.  Also first start on cold engine I've seen white smog out of muffler. What can be wrong?

Answer:  It sounds like you mat have a blown head gasket. Test to repair as needed.

Question: 1988 Chevrolet Corsica mileage: 110,000.  What is the firing order for the spark plugs on this car?

Answer:  The firing order for a 3.8-liter engine is 165432 and for a 2.8-liter, it is 123456.

Question: 1994 Oldsmobile Achieva 2.3 QUAD 4 mileage: 85,000. My Olds Achieva isn't firing on cylinders one and three. I have tested the injector electrical connectors with a neon light and they all flashed. I swapped number one injector with number two and number one cylinder still didn't fire so I don't think it is the injector system. I have changed the spark plugs and the fuel filter also. I have taken the ignition coils and swapped them and the same two cylinders are not working. This engine has the integrated direct ignition so I am not too familiar with the ignition system. I’m trying to avoid the cost of taking it to a dealer. Any suggestions would be greatly appreciated.

Answer: Try replacing the spark plug coil housing to repair the problem. recheck system.

Question: 1995 Nissan Pickup, miles: 89,000. While changing my spark plug wires, I accidentally knocked off the wires on the distributor cap and do not have a wire diagram to replace them. Although it is a 4 cyl., it has 8 wires. Can you help me find the right sequence?

Answer: The distributor rotates counter clockwise. There is a reference to intake side and exhaust side: 2i for cylinder #2 intake side and 2e for exhaust side. Starting from the top and going counter clockwise: 2i, 4e 1i, 2e, 3i, 1e, 4i, and 3e.

MORE: Engine spark plug questions

Repair Topics / Spark Plug-1 / Spark Plug-2