Hydraulic Lash Adjuster (Lifter) Audi 8P/8V/B7/B8/8J & Volkswagen MK5/MK6/MK7 022109423D

Get Hydraulic Lash Adjuster (Lifter) Audi 8P/8V/B7/B8/8J & Volkswagen MK5/MK6/MK7 022109423D

A hydraulic lash adjuster is a component used in the valve train of an engine to maintain zero valve clearance. In simpler terms, it automatically adjusts to ensure that there is no gap between the valve stem and the rocker arm or camshaft. This is crucial because it ensures consistent valve operation, which is essential for optimal engine performance and longevity.

How Does a Hydraulic Lash Adjuster Work?

Hydraulic lash adjusters use engine oil pressure to maintain proper valve clearance. Here’s a step-by-step look at how they function:

1. Oil Supply: Engine oil is supplied to the lash adjuster from the engine’s oil pump. This oil enters the adjuster through small passages.
2. Plunger Movement: Inside the lash adjuster is a small plunger and spring. When the camshaft rotates and a valve begins to open, the force from the cam lobe compresses the plunger against the oil pressure.
3. Zero Clearance: The oil pressure inside the lash adjuster maintains the plunger in a position where there is no gap between the valve stem and the camshaft or rocker arm. This “zero clearance” ensures that the valve opens and closes correctly without any lag or slack.
4. Adjusting for Wear: Over time, as engine components wear down, the lash adjuster compensates for these changes. The oil pressure keeps the plunger correctly positioned, maintaining optimal valve clearance.

Benefits of Hydraulic Lash Adjusters

Hydraulic lash adjusters offer several advantages over mechanical lifters, including:

1. Automatic Adjustment: The primary benefit is their ability to automatically adjust for valve clearance. This means there is no need for manual adjustments, which can be time-consuming and require specialized knowledge.
2. Reduced Maintenance: Because they adjust automatically, hydraulic lash adjusters reduce the need for regular maintenance and adjustments compared to mechanical lifters.
3. Improved Engine Performance: Proper valve clearance is crucial for optimal engine performance. Hydraulic lash adjusters ensure that the valves open and close at the right times, improving engine efficiency and power.
4. Noise Reduction: Hydraulic lash adjusters help reduce valve train noise. By maintaining zero clearance, they prevent the metal-to-metal contact that can cause ticking or tapping sounds.
5. Extended Engine Life: By ensuring proper valve operation and reducing wear on valve train components, hydraulic lash adjusters contribute to longer engine life.

Signs of worn out Hydraulic Lash Adjusters

1. Ticking or Tapping Noise

One of the most noticeable signs of worn-out hydraulic lash adjusters is a ticking or tapping noise coming from the engine, especially when it is idling. This noise is often more pronounced when the engine is cold and can become quieter as the engine warms up. The noise is caused by increased clearance between the valve components due to the lash adjusters not maintaining zero clearance.

2. Poor Engine Performance

Worn hydraulic lash adjusters can lead to poor engine performance. Symptoms may include a rough idle, misfiring, hesitation, or a general lack of power. This occurs because the valves are not opening and closing at the correct times, leading to inefficient combustion.

3. Decreased Fuel Efficiency

If the hydraulic lash adjusters are not functioning properly, the engine may not run as efficiently as it should. This inefficiency can result in decreased fuel economy, as the engine has to work harder to produce the same amount of power.

4. Inconsistent Valve Operation

Worn lash adjusters can cause inconsistent valve operation, leading to irregular engine performance. This inconsistency can manifest as fluctuations in engine speed, especially noticeable at idle, or during acceleration.

5. Excessive Valve Train Wear

When hydraulic lash adjusters wear out, they can no longer maintain the correct valve clearance. This can lead to increased wear on other valve train components, such as the camshaft lobes, rocker arms, and valve stems. Over time, this additional wear can cause more serious and expensive damage to the engine.

6. Engine Warning Lights

In some cases, the engine control unit (ECU) may detect issues related to the valve train and trigger a check engine light or other warning lights on the dashboard. Diagnostic trouble codes (DTCs) related to valve timing or misfires can be an indication of problems with the hydraulic lash adjusters.

7. Difficulty Starting the Engine

Worn-out hydraulic lash adjusters can cause difficulty in starting the engine. This is because improper valve operation can lead to compression issues, making it harder for the engine to start and run smoothly.

8. Oil Pressure Issues

Since hydraulic lash adjusters rely on engine oil to function properly, any issues with oil pressure can affect their performance. If you notice fluctuating or low oil pressure readings, it could be a sign that the lash adjusters are not working correctly, possibly due to internal wear or oil contamination.

9. Visible Damage or Wear

In some cases, visual inspection of the valve train components may reveal damage or excessive wear. If the hydraulic lash adjusters are accessible, signs of wear, such as scoring, pitting, or excessive movement, can indicate that they are no longer functioning properly.

Common Issues with Hydraulic Lash Adjusters

While hydraulic lash adjusters are generally reliable, they can experience problems. Some common issues include:

1. Oil Contamination: Dirty or contaminated oil can clog the small passages in the lash adjuster, preventing it from functioning correctly. This can lead to improper valve operation and increased engine noise.
2. Wear and Tear: Over time, the internal components of the lash adjuster can wear out, leading to a loss of oil pressure and improper valve clearance.
3. Oil Aeration: Air bubbles in the oil can cause the lash adjuster to malfunction. This can happen if the oil level is too low or if there is a leak in the oil system.
4. Sludge Build-Up: Lack of regular oil changes can lead to sludge build-up, which can obstruct the oil passages in the lash adjuster.
5. Cold Start Issues: In cold weather, the oil can become thick and slow to reach the lash adjusters, causing temporary valve train noise until the engine warms up and the oil flows freely.

Maintenance and Care for Hydraulic Lash Adjusters

Proper maintenance is key to ensuring the longevity and optimal performance of hydraulic lash adjusters. Here are some tips for maintaining them:

1. Regular Oil Changes: Regular oil changes are crucial for keeping the lash adjusters clean and functioning correctly. Use the recommended oil type and change it at the intervals specified by the vehicle manufacturer.
2. Quality Oil and Filters: Use high-quality engine oil and oil filters to prevent contamination and ensure proper oil flow to the lash adjusters.
3. Monitor Oil Levels: Regularly check and maintain the proper oil level. Low oil levels can lead to aeration and improper functioning of the lash adjusters.
4. Engine Cleaners: Periodically using engine cleaning additives can help remove sludge and deposits that could clog the lash adjusters.
5. Addressing Oil Leaks: Promptly fix any oil leaks to prevent low oil pressure and contamination of the lash adjusters.
6. Warm-Up Time: In cold weather, allow the engine to warm up before driving to ensure the oil reaches the lash adjusters and they function correctly.