Spark Plug Replacement Cost by Car: 20 Popular Models Compared

The 4-cylinder Camry is one of the easier jobs in the segment. Four plugs in a straight line, all accessible from the top. The V6 Camry is a different story - the rear three plugs sit tight against the firewall and many shops remove the intake plenum to reach them. Ask for a quote that specifies front and rear bank labor separately.

One of the most DIY-friendly vehicles in the US market. The K20/K24 and L15 engines have excellent plug access. A set of NGK Iridium plugs costs about $30-$40 online. Total DIY cost is under $50 including the plugs and a torque wrench if you do not already own one.

This engine from 2004 to 2008 has a design defect: the two-piece spark plug fills the threads with carbon deposits over time. When you try to remove them, the plug snaps leaving a piece embedded in the head. Ford issued TSB 08-7-6. Budget $800 to $1,500 extra if a plug breaks. Always use a shop that has spark plug extraction tools and experience with this engine. Do not DIY.

The horizontal boxer engine mounts the plugs facing outward toward the fender wells. Some shops need to tilt the engine or remove the front subframe for rear plugs on older models. Labor is 2 to 4 hours depending on the technician. The plugs themselves are standard NGK Iridium - the premium cost is entirely labor.

BMW requires OEM-equivalent Bosch or NGK plugs at $12 to $25 each. The N20 4-cylinder is relatively accessible but the engine cover, intake, and coil pack must come off first. Labor is 1.5 to 2.5 hours at BMW dealer rates of $150 to $200/hr. Independent BMW specialists save 30 to 40 percent with the same quality outcome.

The 5.7L and 6.4L HEMI engines use two spark plugs per cylinder for 16 total. This doubles the parts cost but the firing plugs and non-firing plugs alternate, so you technically only need to replace the 8 firing plugs at each service interval. Most shops replace all 16 for reliability. Access on trucks is decent - better than most car V8s.

The 3.6L Pentastar V6 buries the rear bank plugs. Access is tight through the firewall without removing the intake. The 5.7L HEMI variants have the dual-plug setup. Shop around - dealer quotes for this vehicle tend to be significantly higher than independents for the same job.

The 5.3L and 6.2L EcoTec3 engines in recent Silverados have good access from both sides of the engine bay. This is one of the easier V8 jobs. ACDelco Iridium plugs are available at AutoZone for about $12-$14 each. A competent DIYer can do this in 90 minutes.

Transverse V6 engines

When a V6 is mounted sideways (transverse) in a front-wheel-drive car, three of the six plugs face the firewall. Mechanics cannot reach them without removing other components. This is the most common reason a V6 quote shocks people compared to the 4-cylinder version of the same car.

Manufacturer plug requirements

European manufacturers specify expensive OEM plugs. A BMW N52 or Mercedes M272 requires $15 to $25 plugs per cylinder versus $8 to $12 for a Toyota. Multiply that by 6 or 8 cylinders and the parts cost alone doubles versus a Japanese domestic market vehicle.

HEMI dual-plug design

Dodge and RAM HEMI engines use two plugs per cylinder for more complete combustion. 16 plugs instead of 8. The plugs themselves are inexpensive copper, but buying 16 at $5 each is $80 in parts before any labor.

Import pricing on labor

Dealers price labor based on Mitchell flat-rate guides. German cars have higher rated labor hours for spark plug jobs than comparable Japanese or American vehicles. The same 1.5 hours of actual work can be billed at 2.0 hours if the flat-rate guide says so.