Safely Remove Smart Car HT Leads with the Right Tool

Replacing spark plugs is a crucial part of smart car maintenance, ensuring optimal engine performance and fuel efficiency. However, a common challenge for DIY mechanics is safely removing the HT leads (High Tension leads) without causing damage. This guide focuses on the essential tool for this task: the Smart Car Ht Lead Removal Tool. We’ll walk you through why this tool is necessary, how to use it effectively, and how it makes spark plug replacement on your Smart Fortwo or Roadster smoother and safer.

Why You Need a Smart Car HT Lead Removal Tool

Spark plugs in your smart car endure extreme conditions, firing thousands of times per minute in the heart of your engine. Over time, they naturally wear down and require replacement, typically during routine servicing. While the spark plug change itself is straightforward, accessing and removing the spark plug caps connected to the HT leads can be tricky.

The spark plug caps are designed for a snug fit to ensure a reliable electrical connection. This tight fit, combined with years of heat and engine grime, can make them incredibly difficult to remove by hand. Attempting to pull the HT leads directly by the wire is a recipe for disaster. You risk:

• Damaging the HT leads: Pulling on the wire can stretch, fray, or even break the internal conductors, leading to misfires and engine problems. Replacing a full set of HT leads is far more expensive and time-consuming than using the correct tool.
• Breaking the spark plug cap: Excessive force can crack or damage the spark plug cap, requiring replacement and potentially leading to poor spark plug connection.
• Personal injury: Struggling with tight caps can lead to slips and injuries, especially in the confined engine bay of a smart car.

This is where a smart car HT lead removal tool becomes indispensable. This specialized tool is designed to grip the spark plug cap securely, allowing you to apply even pressure and gently lever it off the spark plug without damaging any components.

Step-by-Step Guide to Spark Plug Removal Using an HT Lead Removal Tool

Before you begin, ensure you have the correct new spark plugs for your smart car engine. Refer to your car’s manual or our guide below to identify the right NGK spark plug type for your 599cc or 698cc engine:

Spark Plug Types:

• 599cc Engine: 6 x NGK BKR6EKE
• 698cc Engine: 6 x NGK R LKR8A or 6 x NGK R LKR8AP

Tools You’ll Need:

• Smart Car HT Lead Removal Tool: Essential for safe removal.
• Spark Plug Socket (16mm or 10mm deep socket recommended): For removing and installing spark plugs.
• Socket Extension(s): To reach the spark plugs, especially the lower ones.
• Torque Wrench: For accurate spark plug tightening.
• New Spark Plugs (x6): Correct type for your engine.
• Optional: Copper Grease: For spark plug threads (see notes below).

Removal Process:

1. Access the Spark Plugs:

   • Rear Access (Bottom Plugs): Remove the rear panels of your smart car. Instructions for 450 models can be found here (link to relevant guide if available on your site). For improved access, you can remove the rear crash bar by unscrewing the six Torx45 bolts (three on each end). This is optional but can be helpful depending on the length of your HT lead removal tool and socket extensions.

2. Remove Bottom HT Leads:

   • Locate the three lower spark plug leads.
   • Using your smart car HT lead removal tool, slide the tool down the plug lead until it securely grips the spark plug cap. Rotate the tool slightly to ensure the lugs engage under the “ears” of the cap.
   • Gently but firmly pull the tool to remove the cap. Be patient and avoid excessive force. If the cap is very tight, wiggle the tool slightly while pulling.
   • Repeat for the remaining two lower HT leads. Lay the removed leads aside, taking care not to strain or bend them excessively.

3. Remove Bottom Spark Plugs:

   • Use your spark plug socket and extension(s) to reach and unscrew the lower spark plugs.

4. Access and Remove Top HT Leads and Spark Plugs:

   • Front Access (Top Plugs): Open the “boot” (front trunk) and remove the engine cover.
   • Similar to the bottom plugs, use the HT lead removal tool to carefully remove the top three HT leads. Note that these leads may also be clipped in place; gently unclip them before removal.
   • Before removing the top spark plugs completely, loosen them by a couple of turns. Use compressed air or a straw to blow away any debris from around the spark plug threads. This prevents dirt from falling into the engine cylinder when you fully remove the plugs.
   • Remove the top spark plugs using your spark plug socket and extension.

Spark Plug Replacement and Important Torque Settings

1. Install New Spark Plugs:

   • Optional: Apply a small amount of copper grease to the spark plug threads. While debated, copper grease can prevent seizing and ease future removal (see discussion below).

   • Carefully thread the new spark plugs into their ports by hand to avoid cross-threading.

   • Torque the spark plugs to the correct specifications using a torque wrench:

     • 599cc Engine (NGK BKR6EKE):
       • New: 27.5 Nm
       • Used: 20.0 Nm
     • 698cc Engine (NGK R LKR8A/LKR8AP):
       • New & Used: 22.5 Nm

   • Do not over-tighten the spark plugs! This can damage the threads or the spark plugs themselves.

2. Reattach HT Leads:

   • Push the spark plug caps firmly back onto the new spark plugs. You should feel a click or positive engagement. A gentle tap on the top of the cap with a screwdriver handle or similar tool can help seat them fully.
   • Ensure all HT leads are securely reconnected. For the top plugs, also re-secure the leads into their clips on the engine.

3. Reassemble:

   • If removed, reinstall the rear crash bar.
   • Replace the rear panels and engine cover.

Choosing the Right Smart Car HT Lead Removal Tool

While a basic HT lead removal tool will suffice, investing in a quality tool can make the job easier and further reduce the risk of damage. The original article mentions a Smart branded tool (part number A 638 581 02 67), but notes it can be less effective and prone to slipping.

For better performance and durability, consider tools like:

• Hazet 1849-9 or Hazet 1849-6: These are mentioned as higher quality alternatives and are known for their robust construction and reliable grip.
• Other reputable brands: Look for HT lead removal tools made from strong materials with a comfortable and ergonomic grip.

You can also find universal HT lead removal tools, but ensure they are suitable for the type of spark plug caps used in smart cars.

Copper Grease on Spark Plug Threads: To Use or Not to Use?

The use of copper grease on spark plug threads is a long-standing debate in automotive maintenance.

Arguments for Copper Grease:

• Prevents Seizing: Copper grease acts as an anti-seize compound, making future spark plug removal easier, especially in aluminum cylinder heads where corrosion can occur.
• Reduces Thread Friction: Lubrication reduces friction during tightening, potentially leading to more accurate torque readings.

Arguments Against Copper Grease:

• Over-Torquing Risk: Reduced friction can cause over-tightening if torque values are not adjusted for lubrication.
• Modern Spark Plug Coatings: Many modern spark plugs have special coatings designed to prevent seizing, potentially making copper grease unnecessary.

Recommendation:

If you choose to use copper grease, apply a very small amount to the threads only, avoiding getting any on the spark plug electrodes. Slightly reduce the torque value if using copper grease to compensate for reduced friction (consult a professional mechanic or reliable torque charts for adjusted values). Alternatively, follow the “finger tight plus half a turn” method, which relies on the crush washer to seal properly and may be less sensitive to thread lubrication.

Ultimately, the decision to use copper grease is a matter of personal preference and experience. However, always prioritize correct torque settings to ensure proper spark plug sealing and prevent engine damage.

Conclusion

Replacing spark plugs on your smart car is a manageable DIY task, and using a smart car HT lead removal tool is crucial for a safe and successful job. This tool prevents damage to your HT leads and spark plug caps, saving you time and money on potential repairs. By following this guide and using the right tools, you can maintain your smart car’s engine performance and ensure reliable ignition for miles to come.