Harley Twin Cam Years to Avoid

When it comes to Harley-Davidson motorcycles, their iconic Twin Cam engine is both loved and, in some cases, cursed by enthusiasts. While the engine series brought significant performance upgrades, there were certain model years where buyers and riders reported persistent issues. This detailed guide breaks down the Harley Twin Cam years to avoid, diving deep into the problems you may face and what you can do to fix them.

Whether you’re buying a used Harley-Davidson or already own one, this guide will help you understand which years are more prone to mechanical issues, saving you from unexpected breakdowns and expensive repairs.

Key Takeaways

  • Harley-Davidson’s Twin Cam engines were first introduced in 1999 and ran until 2017.
  • Early models, especially those from 1999-2002, had serious cam chain tensioner issues.
  • Some 2007 models suffered from oil pump and oil sumping problems.
  • Crankshaft runout issues were also common in models produced between 2003-2006.
  • While many of these issues have solutions, knowing the problem years can save you from costly repairs.

Part 1: History and Overview of the Harley-Davidson Twin Cam Engine

The Harley-Davidson Twin Cam engine is a powerhouse that replaced the Evolution engine, starting in 1999. This engine was a major overhaul, offering more power and performance for Harley’s growing fan base. The Twin Cam 88 was the first version, and it was followed by upgrades like the Twin Cam 96 and the Twin Cam 103.

While the Twin Cam engine was a great leap forward in terms of technology, not all production years were created equal. Some early models were notorious for reliability problems that frustrated riders.

1.1 Major Generations of Twin Cam Engines

  • Twin Cam 88 (1999-2006): First generation; featured in many Softail, Dyna, and Touring models.
  • Twin Cam 96 and 103 (2007-2017): Introduced more torque and power but not without some hiccups.

Each engine brought improvements in performance, but certain years experienced recurring mechanical issues, making them models to avoid for buyers looking for long-term reliability.

Part 2: Common Problems with Harley Twin Cam Engines

2.1 Cam Chain Tensioner Failures (1999-2006)

One of the biggest issues reported by owners of 1999-2002 Harley Twin Cam models was the cam chain tensioner failure. This problem was so common that it became a well-known topic in Harley owner forums and blogs.

What is a cam chain tensioner?
The cam chain tensioner is a vital part of the Harley Twin Cam engine’s timing system. It keeps the engine’s timing chain at the right tension so that the engine valves open and close properly.

Unfortunately, in the early Twin Cam models, the plastic cam chain tensioners were prone to wear down much faster than expected. As they wore down, they could eventually fail, leading to catastrophic engine failure.

Symptoms of cam chain tensioner failure include:

  • Rattling or ticking noises coming from the engine
  • Decreased engine performance
  • Complete engine lockup (in worst cases)

Why it’s an issue:
Once the cam chain tensioner fails, it can cause damage to the camshaft, pistons, and even the crankshaft. Repairs can be incredibly costly, often requiring a complete engine rebuild or replacement. This is one reason why 1999-2002 models are considered risky to buy.

2.2 Oil Pump and Oil Sumping Issues (2007 Models)

The 2007 Harley Twin Cam models are notorious for their oil pump and oil sumping problems. Oil sumping occurs when oil doesn’t return from the engine sump to the oil tank, causing the engine to overheat and lose power.

In 2007, Harley introduced the Twin Cam 96, but the oil pump design in some models was flawed. As a result, oil would pool at the bottom of the engine, leading to oil starvation and potential engine failure.

Symptoms of oil sumping problems include:

  • Loss of power, especially at higher speeds
  • Unusual engine knocking
  • Overheating issues

Why it’s an issue:
If oil can’t circulate properly, it leads to engine wear, overheating, and in severe cases, complete engine failure. Replacing the oil pump is a possible fix, but it can be an expensive repair, costing over $1,000 depending on the severity.

2.3 Crankshaft Runout Issues (2003-2006)

Crankshaft runout refers to excessive lateral movement of the crankshaft, which can cause severe vibration and engine wear. Harley’s 2003-2006 models experienced significant problems with crankshaft runout. The issue stems from Harley’s switch to a pressed-together crankshaft in these models, which was more prone to movement under stress.

Symptoms of crankshaft runout issues:

  • Increased engine vibration
  • Premature wear on other engine components
  • Unbalanced engine performance

Why it’s an issue:
If the crankshaft runout exceeds Harley’s specifications, it can lead to total engine failure. Fixing this problem often requires disassembling the engine, realigning the crankshaft, or even replacing it entirely. The cost for this repair can be upwards of $2,000, which is why 2003-2006 models are considered risky purchases.

Part 3: Harley Twin Cam Years to Avoid

While Harley-Davidson worked to improve the Twin Cam engine over its lifespan, certain years remain notorious for reliability problems. Here’s a breakdown of the worst years and why you should avoid them.

3.1 1999–2002: Early Cam Chain Tensioner Problems

As mentioned earlier, the 1999-2002 Twin Cam models are plagued by cam chain tensioner failures. Harley eventually addressed this issue in later models, but the early models remain a big risk for buyers.

Why avoid these years?

  • High tensioner failure rates: The plastic material used wore down much faster than expected.
  • Expensive fixes: Replacing the cam chain tensioner requires tearing into the engine, costing over $1,500 for repairs.

3.2 2007: Oil Pump and Oil Sumping Issues

The 2007 Harley models, especially those equipped with the Twin Cam 96, suffered from oil sumping issues. Harley improved the oil pump design in later years, but 2007 models have a high rate of failure due to this flaw.

Why avoid these years?

  • Frequent oil sumping issues: This leads to engine overheating and power loss.
  • Costly repairs: Replacing the oil pump and fixing the sumping issue can cost $1,000 or more.

3.3 2003–2006: Crankshaft Runout Problems

Crankshaft runout problems in 2003-2006 models make these bikes a risky purchase. If the crankshaft is out of balance, it will cause engine vibration and lead to further damage.

Why avoid these years?

  • Crankshaft failure: Models in this range often require a full crankshaft replacement.
  • High repair costs: Fixing a crankshaft problem can easily exceed $2,000.

Part 4: Are There Fixes for These Problems?

While the Harley Twin Cam years to avoid come with notable issues, some of these problems can be fixed with aftermarket upgrades.

4.1 Upgrading Cam Chain Tensioners

For the 1999-2002 models, upgrading to a hydraulic cam chain tensioner can significantly improve engine reliability. Many Harley riders choose to replace the stock plastic tensioner with aftermarket hydraulic versions, which are more durable.

  • Cost of upgrade: Upgrading cam chain tensioners can cost around $1,200, including parts and labor.

4.2 Oil Pump and Crankshaft Repairs

For 2007 models, upgrading the oil pump is often necessary to prevent oil sumping issues. Aftermarket oil pumps are available that solve this problem by improving oil flow and circulation.

  • Cost of repair: Replacing the oil pump will cost around $1,000.

For models with crankshaft runout issues, a full crankshaft replacement may be necessary. Some riders opt for aftermarket parts that are more durable than the stock pressed-together crankshaft.

  • Cost of crankshaft repair: Expect to pay between $1,500 to $2,500 for crankshaft replacement or repair.

Part 5: Harley Twin Cam Years Worth Buying

While certain Twin Cam years should be avoided, there are plenty of reliable Harley models from later years. Harley made substantial improvements after 2007, making newer models more reliable.

5.1 Post-2007 Models with Upgraded Parts

Harley addressed many of the oil sumping and cam tensioner issues in 2008 and beyond. If you’re buying a used Harley, aim for models from 2008-2017 as they feature improved oil pumps, better cam tensioners, and reduced crankshaft issues.

5.2 Twin Cam 103 Engines (2011–2017)

The Twin Cam 103 engine, introduced in 2011, is widely regarded as one of the most reliable versions of the Twin Cam series. It delivers more power than previous models and is generally free from the tensioner and oil sumping problems that plagued earlier models.

Part 6: FAQs on Harley Twin Cam Engines and Years to Avoid

6.1 What are the worst years for Harley Twin Cam engines?

The worst years are 1999-2002, due to cam chain tensioner failures, and 2007, due to oil pump and oil sumping issues.

6.2 Can you fix the problems with Harley Twin Cam engines?

Yes, many of these problems can be fixed with aftermarket upgrades like hydraulic cam chain tensioners or improved oil pumps, but repairs can be expensive.

6.3 Are newer Twin Cam engines reliable?

Yes, models after 2007, especially those with Twin Cam 103 engines, are generally reliable and free from the issues found in earlier models.