Essential Guide to Spark Plugs for the 1998-2000 Volvo S70
Keep your S70's 5-cylinder engine running smoothly with the right spark plugs and knowledge.
- For best results, especially on turbo models, use Genuine Volvo, Bosch, or NGK spark plugs.
- When replacing plugs, inspect the spark plug wells for oil, which indicates a likely oil cap seal leak that must be fixed.
- Always verify the spark plug gap is correct before installation, even if the plugs are advertised as pre-gapped.
- Replacement is a straightforward DIY job for most owners, taking about an hour with basic tools.
Signs of Failing Spark Plugs in Your S70
Worn-out spark plugs can cause noticeable problems with your Volvo's performance. If you experience any of these symptoms, your spark plugs are a likely culprit.
- Rough Idling: The engine may shake or vibrate more than usual when the car is stopped.
- Engine Misfires: You might feel a stumbling or hesitation from the engine during acceleration. This is often accompanied by a flashing Check Engine Light and codes like P0300, P0301, P0302, P0303, P0304, or P0305.
- Reduced Power and Acceleration: The car may feel sluggish and slow to respond when you press the gas pedal.
- Poor Fuel Economy: You may find yourself filling up the gas tank more often than you used to.
- Difficulty Starting: While less common, very worn plugs can make it harder for the engine to start.
A Common S70 Issue: Oil in the Spark Plug Wells
A frequent problem on 1998-2000 S70 models is a hardened and leaking oil filler cap seal. This allows oil to seep into the spark plug wells, especially the one closest to the oil cap. This oil contamination can foul the spark plug and ignition coil or wire, causing a misfire. When changing your plugs, always inspect the wells for oil. 🎬 See an easy trick for removing oil from spark plug wells. If oil is present, it's crucial to replace the inexpensive oil cap seal to prevent the new plugs from failing prematurely.
Choosing the Right Aftermarket Spark Plugs
While many brands are available, Volvo's 5-cylinder engines, especially the turbocharged versions (GLT, T5, AWD), perform best with specific types of spark plugs. Many owners and mechanics strongly recommend using either Genuine Volvo plugs or plugs from the original equipment (OE) manufacturer.
- Top Tier (Recommended): Genuine Volvo, Bosch, NGK. Genuine Volvo plugs are often made by Bosch or NGK and are engineered for your specific engine. Using these is the safest bet to ensure proper performance and avoid issues, particularly in the sensitive turbo models.
- Mid Tier (Good Quality): Denso. Denso is another well-regarded Japanese brand that produces high-quality iridium and platinum plugs that are a good alternative to OE.
- Economy Tier (Use with Caution): Autolite, Champion. While these brands offer compatible plugs, they are often standard copper plugs which have a much shorter service life. Some forum users have reported issues when using non-OE brands in turbo engines. For a non-turbo S70, they can be a budget-conscious choice if changed frequently.
For turbocharged S70s (T5, GLT), using the recommended Genuine, Bosch, or NGK plugs is highly advised to handle the higher combustion pressures and temperatures.
Do I Need Copper, Platinum, or Iridium?
Your S70 came from the factory with specific plugs. It's best to stick with that technology or upgrade. Copper plugs offer good performance but wear out the fastest (check every 30,000 miles). Platinum and Iridium plugs last much longer (60,000-100,000 miles) and provide a more consistent spark over their lifespan. For the labor involved, installing a longer-life platinum or iridium plug is often the most cost-effective choice.
Typical Replacement Costs
| Item | Estimated Cost |
|---|---|
| New Aftermarket Spark Plugs (Set of 5) | $15 - $150 |
| Shop Labor | $100 - $200 |
| Total Estimated Cost | $115 - $350 |
Costs are estimates and can vary based on location, parts brand, and the repair shop's labor rates. The price of parts can vary significantly based on the brand and material (copper vs. iridium).
Frequently Asked Questions
Is replacing the spark plugs a DIY job?
Yes, for most home mechanics this is a very feasible DIY job. It requires basic tools and should take between 30 and 90 minutes. 🎬 Watch this step-by-step guide to replacing your S70 spark plugs. You will need a socket set, a T30 Torx driver for the engine cover, a 10mm socket for the ignition coils 🎬 Watch a walkthrough for replacing both spark plugs and coil packs. (on later models), and a 5/8" (or 16mm) spark plug socket with an extension.
What is the correct spark plug gap for my S70?
For turbocharged models, the recommended gap is typically 0.028 inches (0.7mm). Non-turbo models may have a slightly different specification. While many modern plugs come pre-gapped, it is always a good practice to check the gap with a feeler gauge before installation.
Should I use anti-seize on the new spark plugs?
Most modern spark plugs from brands like NGK and Bosch have a special trivalent plating that acts as an anti-seize agent. Applying additional anti-seize can act as a lubricant, causing you to over-torque the plug and potentially damage the cylinder head threads. It is generally recommended not to use anti-seize on these plated plugs.
Are there any recalls or TSBs for S70 spark plugs?
There are no specific recalls or Technical Service Bulletins (TSBs) for spark plugs on the 1998-2000 Volvo S70. The most common related issue is the oil leak from the filler cap seal fouling the plugs, which is not a recall item.
Helpful Videos
Technical Specifications
OEM Part Numbers: 8692071 8642660
Thread Size: M14 x 1.25mm. Spanner/Wrench Size: 16mm (5/8"). Gap (Turbo): 0.028" (0.7mm). Tightening Torque: 18-22 ft-lbs (25-30 Nm).
We Have This Part in Stock
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.
- Volvo S70: