Mercury Monarch Spark Plug Replacement at your home or office.

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Spark Plug Replacement Estimate for Mercury Monarch

Mercury Monarch Spark Plug Replacement costs $147 on average.

CarServiceEstimateShop/Dealer Price
1978 Mercury MonarchL6-4.1LService typeSpark Plug ReplacementEstimate$194.31Shop/Dealer Price$230.29 - $310.33
1975 Mercury MonarchV8-5.0LService typeSpark Plug ReplacementEstimate$205.75Shop/Dealer Price$249.61 - $353.24
1979 Mercury MonarchL6-4.1LService typeSpark Plug ReplacementEstimate$174.31Shop/Dealer Price$210.31 - $290.36
1977 Mercury MonarchV8-5.0LService typeSpark Plug ReplacementEstimate$205.75Shop/Dealer Price$249.59 - $353.20
1979 Mercury MonarchV8-5.0LService typeSpark Plug ReplacementEstimate$205.75Shop/Dealer Price$249.62 - $353.27
1976 Mercury MonarchV8-5.0LService typeSpark Plug ReplacementEstimate$205.75Shop/Dealer Price$249.61 - $353.24
1975 Mercury MonarchL6-4.1LService typeSpark Plug ReplacementEstimate$179.31Shop/Dealer Price$215.17 - $295.12
1980 Mercury MonarchV8-5.0LService typeSpark Plug ReplacementEstimate$210.75Shop/Dealer Price$254.84 - $358.66
Show example Mercury Monarch Spark Plug Replacement prices

Spark Plug Replacement Service

What are spark plugs and how do they work?

Spark plugs are one of the key components of your vehicle’s ignition system. They ignite gasoline and air inside of your engine. This gives your engine the power to propel you down the road. The spark plug takes high voltage electricity from the ignition coil and creates a spark at just right moment during the engine’s combustion cycle. This gives the engine the best mix of power, fuel economy and low emissions. However, the electrode at the end of the spark plug eventually wears out and can cause performance issues.

Spark plugs-MATROX-1

When should you replace spark plugs?

Replacement should follow the vehicle maintenance schedule. This will be listed in the vehicle’s owner’s manual. Some cars require regular replacement at 30k, 60k or 100k miles. It is possible in some cases that a spark plug might fail before the service schedule, but it’s not typically common.

Avoiding spark plug replacement can cause:

  • Difficulty starting your car.
  • Check engine light for a misfire code.
  • Flashing check engine light during acceleration for misfire, this can cause engine damage.
  • Reduced fuel economy and/or power.
  • Rough idle and/or unexplained engine vibration.
  • Failed State emission testing.

Even if only one spark plug is found to be faulty, they should always be replaced in sets. Most engines will require 4,6, or 8 spark plugs.

How do mechanics replace spark plugs?

Spark plugs are threaded into the engine’s cylinder head(s). Most cars have one plug per cylinder, so a four-cylinder engine will have four plugs, a six-cylinder engine will have six plugs, and so forth. The mechanic will:

  • Have the correct spark plugs on hand for your vehicle
  • Pull any diagnostic trouble codes that may be related to worn spark plugs.
  • Remove the original spark plugs and look at removed spark plugs for any clues indicating engine mis-operation exists; such as oil burning, excessively rich mixture, pre-ignition damage etc. Inform owner of any found unusual conditions.
  • Install new plugs using a torque wrench.
  • Finally, a road test of the vehicle to confirm normal operation.

Is it safe to drive with worn spark plugs?

Yes, but spark plugs that are worn enough to cause engine-misfiring have the potential to cause engine damage and overheating of the catalytic converter. Regardless of the age of the plugs, or mileage, if the engine misfires or runs poorly, the plugs should be inspected for defects. Generally, spark plug failure will not keep the engine from running, but in cases of extreme wear, you may experience a limitation in the speed at which you can drive the car. If the maintenance schedule says the plugs should be replaced, it is best to do so promptly.

When having spark plugs replaced keep in mind:

  • High-speed driving may accelerate spark plug wear. Consider earlier than required inspection and tune-up if you operate the car in severe conditions.
  • Plugs should always be promptly replaced per the manufacturer maintenance schedule even if they appear to be working perfectly.
  • If your vehicle is equipped with spark plug wires (as opposed to a coil-on-plug system), the wires should be replaced at the same time. This may increase the cost of your repair.
  • It is possible that when doing a spark plug replacement, your vehicle may also need additional parts like ignition coils, this will add to the repair cost.
  • Some engines require that the intake manifold be removed while replacing spark plugs. This may increase the parts and labor cost for the repair.
  • Leaking valve cover gaskets, which have let oil get in contact with the spark plugs, coils or wires, may be the cause of ignition system issues. Valve cover gaskets will need to be replaced in addition to the spark plugs, wires or coils. This will add to the repair cost.

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Meet some of our expert Mercury mechanics

Real customer reviews from Mercury owners like you.

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Rating Summary
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Steven

14 years of experience
425 reviews
Steven
14 years of experience
Mercury Sable V6-3.0L - Spark Plugs - Surprise, Arizona
Steve is very professional, and great to work with!

Peter

43 years of experience
1321 reviews
Peter
43 years of experience
Mercury Mountaineer V8-4.6L - Spark Plugs - Glendale, Arizona
Peter was extremely professional and friendly and I was extremely satisfied with his service and I would 100% recommend him for a raise

Ronnie

30 years of experience
92 reviews
Ronnie
30 years of experience
Mercury Mariner V6-3.0L - Spark Plugs - Pegram, Tennessee
Ronnie was great! He was very understanding and helpful. Will definitely be using him again.

Jeremy

20 years of experience
545 reviews
Jeremy
20 years of experience
Mercury Mountaineer V8-5.0L - Spark Plugs - West Palm Beach, Florida
Jeremy went right to work on the Task and did not let up until he was done. He is My Mechanic of choice in this area. Jeremy knows what he is doing and it shows. I would not hesitate to recommend him for any auto services.

Excellent Rating

(49)

Rating Summary
48
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1
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Number of Mercury Spark Plugs Replacement services completed
539+
services done by our mechanics
TOTAL NUMBER OF EXPERT Mercury MECHANICS
600+
experts on our platform

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