Our mobile mechanics offer services 7 days a week. Upfront and transparent pricing.
Included for free with this service
Online Booking
Mechanic comes to you
12-month / 12k-mile warranty
Free 50 point safety inspection
Our certified mobile mechanics can come to your home or office 7 days a week between 7 AM and 9 PM.
On average, the cost for a Mercedes-Benz 420SEL Spark Plug Replacement is $198 with $58 for parts and $140 for labor. Prices may vary depending on your location.
| Car | Service | Estimate | Shop/Dealer Price |
|---|---|---|---|
| 1991 Mercedes-Benz 420SELV8-4.2L | Service typeSpark Plug Replacement | Estimate$293.88 | Shop/Dealer Price$334.90 - $443.79 |
| 1990 Mercedes-Benz 420SELV8-4.2L | Service typeSpark Plug Replacement | Estimate$284.87 | Shop/Dealer Price$322.80 - $429.37 |
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.
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:
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.
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:
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.
Fast and easy service at your home or office
Backed by 12-month, 12.000-mile guarantee
Real customer reviews from Mercedes-Benz owners like you.
Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.
