How to Adjust Valve Shims on Audi 5 Cylinder 10V Turbo Engines – Full DIY Guide

“Audi 5 Cylinder 10V Turbo Valve Shims “If you’re working on an Audi 5-cylinder 10-valve turbo engine, you’ve probably come across the topic of valve shims. It’s one of those jobs that’s easy to overlook but incredibly important for keeping the engine running at its best. Whether you’re restoring a classic Audi Quattro or simply maintaining a turbocharged daily driver, adjusting the valve shims is a crucial part of keeping that iconic five-cylinder engine healthy.

This guide breaks down what valve shims are, how to tell when they need attention, and how to adjust them yourself, step by step.

What Are Valve Shims and Why Do They Matter?

Valve shims are small, flat discs made of hardened steel that sit between the camshaft lobe and the top of the valve lifter (also called a bucket or follower). Their job is to help maintain the correct “valve lash”—the tiny gap between the camshaft and the lifter when the valve is fully closed.

In solid lifter setups like those found in Audi’s older 10-valve turbo engines, this clearance doesn’t adjust itself automatically. If the gap is too wide, the valves may not open fully, or the valvetrain might make a ticking noise. If it’s too tight, the valves might not close completely, leading to loss of compression or even valve damage.

Getting the clearance just right is essential to engine performance, reliability, and longevity.

Tools and Equipment You’ll Need

Before you start, make sure you have the right tools. Some of these are basic, but a few are specific to this kind of job:

• Feeler gauges (metric)

• Micrometer or digital caliper

• Valve shim kit or individual shims in 0.05mm increments

• Magnetic pickup tool or fine tweezers

• Valve lifter compressor tool (optional but helpful)

• Socket set and ratchet

• Torque wrench

• Service manual for your specific engine code (e.g., MC1, 3B, WR)

It’s also helpful to have a clean workbench or space where you can keep track of each shim and valve position.

Preparing the Engine

Start with a cold engine. Valve lash measurements are only accurate when everything is at room temperature.

1. Disconnect the battery.

2. Remove the spark plugs (this makes turning the engine easier).

3. Remove the valve cover and timing belt cover if needed.

4. Rotate the engine manually using a socket on the crankshaft pulley until the cam lobe you’re measuring is pointing straight up—away from the follower.

Measuring the Valve Clearance

Use your feeler gauge to slide between the cam lobe and the follower. You’re looking for the gauge that fits snugly with just a bit of drag.

Record the clearance for each valve. You’ll want to compare these numbers to the factory specs:

• Intake valve clearance: 0.20mm – 0.30mm

• Exhaust valve clearance: 0.35mm – 0.45mm

Any valve outside of these ranges will need adjustment.

Calculating the Correct Shim Size

To adjust the clearance, you’ll replace the existing shim with one of a different thickness. First, you need to know the current shim’s thickness. If you’re removing it, use a micrometer to measure it. If you’re reusing an old shim and already know its thickness, great.

Here’s the basic formula:

New Shim = Old Shim + (Measured Clearance – Desired Clearance)

For example:

• Measured clearance: 0.45mm

• Desired clearance: 0.30mm

• Old shim: 3.40mm

So: 3.40 + (0.45 – 0.30) = 3.55mm
You’d replace the old shim with a 3.55mm one.

Replacing the Shims

If you’re lucky enough to have a valve lifter compressor tool, use it to press down on the lifter and expose the shim. Otherwise, you may need to remove the camshaft (depending on your engine and tool access).

1. Use a magnet or tweezers to carefully lift out the shim.

2. Install the new shim, making sure it sits flat in the lifter.

3. Rotate the crank and recheck the clearance.

4. Repeat for any other valves that need adjustment.

Be patient here. Precision is important, and rushing this step can lead to errors or even damage.

Reassembly and Final Checks

Once all shims have been adjusted:

1. Wipe down the gasket surfaces and reinstall the valve cover with a fresh gasket if needed.

2. Reinstall spark plugs, ignition components, and reconnect the battery.

3. Start the engine and listen. A properly adjusted valvetrain should run quietly with no metallic ticking.

4. Take the car for a short drive and let it fully warm up. Listen again for any unusual sounds.

If everything sounds good, you’re done. If you still hear ticking or other issues, you may need to double-check your measurements and shim calculations.

Common Mistakes to Avoid Audi 5 Cylinder 10V Turbo Valve Shims

• Guessing shim sizes: Always measure, don’t assume.

• Not keeping track of each valve’s clearance and shim size: Use a chart or spreadsheet to stay organized.

• Using poor-quality shims: Cheap shims can wear prematurely and damage the cam.

• Working on a hot engine: Heat affects metal expansion and throws off your measurements.

• Overtouting bolts: Especially on the valve cover—stripping threads or warping the cover can cause leaks.

Helpful Tips

• If you’re doing a full shim adjustment, consider getting a complete shim kit so you have a range of sizes on hand.

• Label each valve and shim clearly—numbering 1–10 helps keep things simple.

• This is also a good time to inspect the camshaft lobes for any pitting, wear, or signs of oil starvation.

Final Thoughts about Audi 5 Cylinder 10V Turbo

Adjusting the valve shims on an Audi 5-cylinder 10V turbo engine might sound like a job best left to professionals, but it’s absolutely something a skilled and careful DIYer can tackle at home. It takes time and attention to detail, but the reward is worth it: a smoother-running, more efficient engine that sounds and performs exactly how Audi intended.

Whether you’re maintaining a piece of rally heritage or just trying to keep your classic daily driver on the road, understanding and adjusting valve clearance is a key part of keeping that legendary five-cylinder alive.