Introduction
The audi 5 cylinder 10v turbo valve shims engine is a mechanical marvel—powerful, reliable, and beloved by enthusiasts. But like any high-performance engine, it needs a bit of TLC to run at its best. One often overlooked area is the valve shims. If you want that engine to purr (or roar) like it did when it left the factory, then maintaining and adjusting those shims is essential.
Understanding Valve Shims
What Are Valve Shims?
Valve shims are tiny discs of metal that sit between the camshaft and the valve tappets. Their job? Ensure the valve opens and closes at the precise moment it’s supposed to by maintaining the correct clearance.
Why Valve Clearance Matters
Too much clearance means the valve opens late and closes early—killing power. Too little, and the valve might never fully close—roasting itself over time. Either way, the engine suffers.
Common Signs of Improper Shim Adjustment
- Ticking or tapping noise from the top end
- Rough idle or misfires
- Loss of power or throttle response
- Poor fuel efficiency
Audi 5 Cylinder 10V Turbo Engine Basics
A Brief History
This engine was a staple in legendary models like the Audi 200 Quattro and early S-series cars. It combines inline-5 layout harmony with the kick of a turbocharger.
Engine Codes to Know
- MC – Found in the Audi 200 Turbo
- 3B – First-generation Audi S4
- WR – Audi Ur-Quattro
These engines use solid lifters, not hydraulic, which means periodic manual adjustment of valve shims is necessary.
Tools and Equipment Needed
Essential Tools
- Feeler gauge set (metric)
- Micrometer or digital caliper
- Valve depressor tool
- Magnet tool for shim removal
- Torque wrench
Optional Tools
- Camshaft holder or locking tool
- Valve shim kit (pre-sized shims)
- Shop manual or repair guide
Safety Gear
- Safety glasses
- Gloves
- Shop towels and degreaser
Preparing for the Adjustment
- Let the engine cool down completely—valve clearance is measured cold.
- Disconnect the battery.
- Remove intake piping, spark plug wires, and valve cover bolts.
- Take off the valve cover and set it aside.
Measuring Valve Clearance
Step-by-Step
- Rotate the engine so the cam lobe for the valve you’re checking points straight up.
- Slide the feeler gauge between the cam and shim.
- You should feel slight resistance—like pulling a piece of paper under a magnet.
Ideal Specs (Cold Engine)
- Intake: 0.15 mm ± 0.05 mm
- Exhaust: 0.35 mm ± 0.05 mm
(Check your engine code for specifics)
Diagnosing the Need for Shim Adjustment
Too tight? You risk burnt valves. Too loose? You get noise and reduced performance. If your readings fall outside the spec range, it’s time to adjust.
Removing Old Shims
Some engines allow shim removal without pulling the camshaft—others don’t.
- Use a valve depressor to press the tappet down.
- Use a magnet to lift the shim.
- Measure it with a micrometer and record the value.
Pro tip: Keep shims organized. Don’t mix them up.
Selecting and Installing New Shims
How to Calculate New Shim Size
New Shim Thickness = Old Shim Thickness + (Measured Clearance – Desired Clearance)
Example:
- Old shim: 3.00 mm
- Measured clearance: 0.40 mm
- Desired: 0.35 mm
New shim = 3.00 + (0.40 – 0.35) = 3.05 mm
Install the new shim, re-measure, and make sure it’s within spec.
Reassembling the Engine
- Clean the gasket surface thoroughly.
- Install a new valve cover gasket.
- Tighten the valve cover bolts in a crisscross pattern using proper torque.
Post-Adjustment Checks
- Reconnect the battery.
- Start the engine and listen. A quiet top-end is a happy top-end.
- Check for oil leaks around the valve cover.
Maintenance Schedule and Best Practices
- Check every 30,000–50,000 miles depending on driving style.
- Use high-quality synthetic oil.
- Avoid extended oil change intervals—dirty oil accelerates shim wear.
Common Mistakes to Avoid
- Not letting the engine cool before measuring.
- Guessing shim size instead of measuring.
- Over-torquing the camshaft caps or valve cover bolts.
Performance Benefits of Proper Adjustment
- Smoother idle
- Snappier throttle response
- Boost comes on cleaner and stronger
- Improved fuel economy
- Reduced wear on valvetrain components
When to Seek Professional Help
- If you’re unsure about shim math
- If you hear knocking after reassembly
- If camshaft removal feels risky
- Or simply… if you don’t have the tools!
Conclusion
Taking the time to adjust your Audi 5 Cylinder 10V Turbo valve shims isn’t just about maintenance—it’s about unleashing the beast under the hood. It keeps your engine running smoother, harder, and longer. Whether you’re cruising highways or boosting on back roads, precision valve clearances ensure that five-cylinder symphony stays in tune.