What is the torque spec for spark plugs on a 2017 Ford Fiesta ST?
The official spark plug torque spec for the 2017 Ford Fiesta ST is 14 N·m (103 in-lb).
This article explains the specification, why it matters for the turbocharged 1.6-liter EcoBoost engine, and practical guidance for replacing spark plugs correctly to ensure a proper seal and reliable engine performance.
Understanding the specification and its importance
The Fiesta ST uses a turbocharged 1.6L EcoBoost engine, and tightening spark plugs to the correct torque ensures a proper seal with the cylinder head and prevents thread damage in aluminum components. Under-tightening can lead to misfires or leaks, while over-tightening risks cross-threading or stripping the threads.
Before listing the core guidance, here is a concise overview of what this specification covers and why it matters for maintenance and performance.
Key considerations
Before each list, here is an informative paragraph that explains the upcoming points about the torque specification and installation context.
- Torque value: 14 N·m (103 in-lb) for factory spark plugs on the 2017 Fiesta ST.
- Plug type: Use OEM or equivalent iridium plugs recommended for the 1.6L EcoBoost; aftermarket plugs should meet Ford's heat range and description specifications.
- Best practice: Clean threads, use a calibrated torque wrench, and avoid anti-seize on modern spark plugs unless Ford's manual specifically allows it.
Concluding paragraph: The above points summarize the essential torque value and installation context for the Fiesta ST spark plugs.
Practical steps for performing the replacement
Below is a straightforward, step-by-step approach to replacing spark plugs on the 2017 Fiesta ST, with emphasis on applying the correct torque and maintaining thread integrity.
- Prepare the vehicle: disconnect the battery, remove coil packs or ignition rails, and clean around the plug wells to keep debris out of the cylinders.
- Thread plugs by hand to ensure proper alignment, then tighten to 14 N·m (103 in-lb) with a calibrated torque wrench. Avoid overshooting the specified torque.
- Reconnect ignition components, check for proper seating, and perform a cold start to verify there are no misfires or leaks.
Concluding paragraph: Adhering to the torque specification helps prevent thread damage and ensures a reliable seal under the engine's operating conditions, especially in a turbocharged setup.
Additional notes and recommendations
For best results, verify the exact plug type and torque value against the official Ford workshop manual for your specific vehicle revision, as there can be minor variations by model year or plug brand. Use a high-quality torque wrench capable of measuring in Newton-meters, and avoid reusing damaged or corroded plugs.
Summary
Bottom line: The factory torque specification for spark plugs on the 2017 Ford Fiesta ST is 14 N·m (103 in-lb). Monitor Ford’s official service documentation for any year-specific notes or plug recommendations, and follow a careful installation routine to ensure a proper seal and engine reliability.
What torque should spark plugs be tightened to?
Spark plug torque specs vary by manufacturer and plug type, so it is crucial to consult your vehicle's service manual. A general range for common 14mm spark plugs with a gasket is 15–25 ft-lbs, but this can differ for plugs with tapered seats or different thread sizes. For many modern applications, a common spec is around 18 ft-lbs. Always follow the manufacturer's instructions to prevent damage from over- or under-tightening.
This video explains how to torque spark plugs with an example: 1mPhillips VisionYouTube · Jun 29, 2021
General guidelines
- Check your manual: Always refer to your vehicle's service manual for the precise torque specification.
- Use a torque wrench: A torque wrench is essential for ensuring the correct tightness.
- Hand-tighten first: Start by hand-tightening the spark plug to avoid cross-threading, then use the torque wrench to finish the job.
- Proper torque is vital: Too little torque can cause compression loss, while over-tightening can strip the threads or break the plug.
Examples of torque specifications
- Common 14mm gasket type: 18 ft-lbs is a frequent specification. Other sources suggest a range of 15–25 ft-lbs, depending on the specific plug and cylinder head material.
- Different sizes and seat types:
- M14 (cast iron head): 20 N·m (approx. 14.8 ft-lbs)
- M14 (aluminum head): 17.5 N·m (approx. 13 ft-lbs)
- Tapered seat: Often requires a smaller torque value and a specific turn angle, such as 1/16th of a turn after hand-tightening.
- Champion tapered seat: 1/16th of a turn after hand-tightening.
- Champion gasket type: ⅜–⅝ of a turn for a new gasket, or ¼ turn for a used gasket.
You can watch this video to learn how to hand-tighten spark plugs before torquing: 55s603 Mechanic vidsYouTube · Dec 22, 2023
What is the torque spec for Ford spark plugs?
Ford spark plug torque specifications vary by model, engine size, and cylinder head material, so always check the owner's manual for your specific vehicle. However, many Ford engines have updated torque specs in the 20-22 ft-lbs range for modern engines (like the 4.6, 5.4, and 6.8), while older or smaller engines may require lower torque, around 13 ft-lbs (1996 F150) or even lower for some modern applications (e.g., 12 ft-lbs for 2015+ S550 Mustang factory plugs), as shown by Wise Auto Tools, this YouTube video, this JustAnswer page, and Mustang6G.com. It's crucial to use a torque wrench to prevent damage from over-tightening or misfires from being too loose.
Common torque specifications
- For many modern Ford engines (e.g., 4.6L, 5.4L, 6.8L): 20-22 ft-lbs
- For a 2007 F-150 5.4L: 15-22 ft-lbs
- For a 2006 Ford Expedition: 22 to 28 ft-lbs (30-38 Nm) for SP-546 and SP-547 plugs
- For a 1996 Ford F-150: 13 ft-lbs
- For some 2015+ S550 Mustang factory plugs: 12 ft-lbs
Why torque specifications vary
- Engine Design: Different engines are designed with different materials and tolerances.
- Cylinder Head Material: The material of the cylinder head (e.g., aluminum vs. cast iron) affects the required torque.
- Spark Plug Design: The design of the spark plug itself, including the thread diameter and seat type, influences the torque requirement.
- Updated Specifications: Some older engines had lower torque specs that were found to cause issues, leading to updated, higher torque recommendations to prevent the plugs from backing out.
This video demonstrates how to properly torque a spark plug in a Ford F-150: 47sTRQYouTube · May 22, 2023
Important tips
- Always check your specific vehicle's repair manual or the manufacturer's recommendations for the correct torque specifications before you begin.
- Ensure you are using a properly calibrated torque wrench to avoid over-tightening, which can strip the threads or damage the cylinder head.
- Tighten spark plugs dry, without any anti-seize or lubricant on the threads, unless the plug manufacturer specifically instructs otherwise.
What is the torque spec for spark plugs Ford Fiesta?
And 12 new meters is about 1007 in our case we go 110. So That's that will be plenty about 110 inch pounds or 12 new Some People Say To Go Like 25 but do not Risk do not Go that. Much.
How to change spark plugs on Ford Fiesta ST?
And then we can use an 8 mm socket in order to remove the coil packs from the engine. Once you have those all loosened go ahead and remove each of the coil packs. And just set them aside somewhere.
