Go-Parts
Cart 0
Your cart is empty
Add an item to see it appear here.
Wrenchy
Go-Parts Garage
Expert guides for diagnosing, troubleshooting, and replacing auto parts Expert guides for diagnosing and replacing auto parts
Browse All →
🛍️ Shop This Part

Choosing the Right Spark Plugs for Your 1961-1978 Simca 1000

Keep your classic Simca's rear engine running smoothly with the right set of plugs.

3 minutes to read 1946-1961 Simca 1000
Difficulty
1/5
Est. Time
0.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$50-$100
⚠️ Drivable, but... — You can drive with failing spark plugs, but you will experience poor performance and could risk damaging other ignition components over time.
Key Takeaways
  • The Simca 1000 was made from 1961-1978; the years 1946-1961 are incorrect.
  • Use standard copper-core spark plugs, such as those from Champion, as they are best suited for the original ignition system.
  • Always check and set the correct spark plug gap (around 0.025 inches) before installation.
  • Failing plugs cause rough idle, misfires, and hard starts; replacement is a simple and effective DIY task.
The spark plug in your Simca 1000 has a simple but critical job. It creates a small, powerful spark of electricity inside the engine's cylinders. This spark ignites the mixture of air and fuel. This controlled explosion is what powers your car. For the rear-mounted engine in the Simca 1000, having a consistent and strong spark is essential for smooth idling, good acceleration, and proper fuel economy. Without a good spark, the engine can run poorly or not at all.

Signs of Failing Spark Plugs in Your Simca 1000

The spark plugs in your Simca are wear items, meaning they need to be replaced as part of regular maintenance. As they get old, the metal electrodes wear down, and deposits can build up. This makes it harder for them to create a good spark. You might notice a few signs that your plugs are ready for a change.

  • Rough Idle: Your car may shake or vibrate more than usual when stopped.
  • Engine Misfires: You might feel a hesitation or stumbling from the engine, especially when accelerating.
  • Difficulty Starting: A weak spark can make it hard for the engine to fire up, especially when cold.
  • Reduced Fuel Economy: If the fuel isn't burning efficiently, you'll find yourself visiting the gas station more often.

A Note on Vehicle Model Years

The Simca 1000 was produced from 1961 to 1978. The years 1946-1961 are incorrect for this model. This guide applies only to the correct 1961-1978 production years.

Choosing the Right Aftermarket Spark Plug

For a classic car like the Simca 1000, sticking to the basics is often the best approach. The original ignition system was designed for standard copper-core spark plugs. Modern plugs made of platinum or iridium, while great for new cars, are not necessary and may not perform well in your Simca's engine.

Champion is a well-known brand that has been making spark plugs for a very long time and is a suitable choice for the Simca 1000. Their standard copper plugs provide reliable performance and are a cost-effective option. When buying, the most important factors are choosing the correct thread size and heat range for your specific engine, as different Simca 1000 models had slightly different engines over the years.

Pro Tip: Always check the spark plug gap before installation. Even if the plugs are pre-gapped, they can be knocked out of spec during shipping. A feeler gauge is a simple tool to verify the gap is correct for your car's specifications, which is often around .025 inches.

Aftermarket Spark Plug Cost for Simca 1000

Part Type Price Range
New Aftermarket (Champion Copper) $3.68 - $12.36 per plug
New OEM Not Widely Available

Frequently Asked Questions

How often should I change my Simca 1000's spark plugs?

For a classic car with standard copper plugs, a good interval is every 10,000 to 20,000 miles, or every few years if you don't drive it often. It's an inexpensive maintenance item that makes a big difference in performance.

What is the correct spark plug gap for a Simca 1000?

The recommended gap can vary slightly by year and engine model, but a common specification is around 0.025 inches (0.6mm). Always consult a service manual for your specific model if possible.

Can I use modern platinum or iridium plugs in my Simca?

While they might fit, it's generally not recommended. The ignition systems in classic cars like the Simca 1000 were not designed for these types of plugs. You will get the best and most reliable performance from a standard copper-core plug like the Champion Copper Plus.

Is it hard to change the spark plugs on a Simca 1000?

No, it is a very feasible DIY job. Access to the plugs on the rear-mounted engine is generally straightforward. You will need a spark plug socket, a ratchet, and a gap gauge. Some owners with modified carburetors note that access can become tight.

Technical Specifications

Thread Size: 14mm, Reach: 19mm (3/4"), Hex Size: 13/16", Gap: ~0.025" (0.6mm)

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Spark Plug for:
In this article
🛍️ Shop This Part
Jump to ▴

Email This Guide

We'll send you a link to this article so you can read it later or share it.

Added to cart · Part