How To Get Rid Of The Hemi Tick: A Complete Repair And Prevention Guide

Eliminating the "Hemi Tick" requires a precise diagnostic distinction between external exhaust manifold bolt failures and internal hydraulic roller lifter seized bearings. Resolving the issue permanently involves either replacing broken grade-8 manifold bolts or performing a complete top-end teardown to install non-MDS lifters and high-volume oil pumps to maintain a minimum of 25-30 PSI at hot idle.

Pre-Diagnostic Assessment and Mechanical Requirements

Before attempting to dismantle a 5.7L, 6.1L, or 6.4L Hemi engine, you must determine whether the noise is a rhythmic mechanical "clack" (valvetrain failure) or a "chirp/snap" (exhaust leak). The Chrysler Hemi architecture uses a pushrod-driven overhead valve (OHV) design where the camshaft is located high in the block. This design creates a unique lubrication challenge, particularly at idle when oil splash is minimized, leading to the two most common "tick" sources.

Essential Gear and Diagnostic Tools

• Mechanical Stethoscope: Required to isolate the sound to either the valve covers (lifters) or the exhaust heat shields (manifold bolts).
• Precision Torque Wrench: Must support 15 to 200 ft-lbs for head bolts and manifold fasteners.
• 1/4-inch Drive Thin-Wall Sockets: Specifically for reaching the rear manifold bolts near the firewall on Ram and Durango platforms.
• Extraction Kit: Reverse-drill bits and bolt extractors for sheared manifold studs.
• Replacement Components: Multi-layer steel (MLS) head gaskets, intake manifold gaskets, and high-quality synthetic oil (API Service SP).

Project Benchmarks

• Estimated Duration: Exhaust bolt repair (3–5 hours); Lifter and Camshaft replacement (15–20 hours).
• Technical Difficulty: Advanced DIY to Professional.
• Budget Range: $150 (Exhaust) to $2,500+ (Internal Valvetrain).

Comprehensive Restoration Workflow for Hemi Engines

Step 1: Isolate the Failure Point via Acoustic Analysis

The first step in getting rid of the tick is identifying the frequency and behavior of the sound. Start the engine from a cold soak. If the tick disappears after the engine warms up (2–5 minutes), the metal has expanded and sealed an exhaust leak. If the tick persists or worsens as the oil thins out at operating temperature, the failure is internal.

• Use the stethoscope probe on the exhaust manifold heat shield. A sharp "puffing" sound confirms a broken bolt.
• Place the probe on the center of the valve cover. A heavy metal-on-metal "clack" at half the engine's RPM indicates a lifter roller has seized and is grinding the camshaft lobe.
• Check the oil filter for non-ferrous metallic flakes. If you see "gold dust," the lifter bearings have disintegrated and the camshaft is being destroyed.

Step 2: Remediating Exhaust Manifold Bolt Failures

If your diagnosis points to the exhaust, the "tick" is actually high-pressure exhaust gas escaping through a gap created by sheared bolts. This is usually caused by the heat-cycle expansion of the cast-iron manifold against the aluminum cylinder head.

1. Remove the wheel well liners (on truck models) to gain direct access to the manifold.
2. Inspect the rear-most bolts (cylinders 7 and 8). These are the most common failure points.
3. Remove the remaining manifold bolts and pull the manifold. If a bolt is broken flush with the head, use a welding nut technique or a specialized extraction jig.
4. Check the manifold for warping. Use a straight-edge; if the surface deviation exceeds 0.004 inches, the manifold must be machined flat or replaced.
5. Install new 6.1L SRT-grade gaskets and use Grade 8 stainless steel bolts. Torque to 23 ft-lbs, starting from the center and working outward.

Step 3: Top-End Disassembly for Lifter Access

If the tick is internal, you must remove the cylinder heads. The lifters in a Hemi engine are located in "buckets" or plastic yokes underneath the heads. You cannot access them through the valley cover alone.

1. Drain the cooling system and remove the air intake, throttle body, and upper intake manifold.
2. Disconnect the fuel rail (depressurize first) and remove the coil packs.
3. Remove the valve covers and the rocker arm assemblies. Note the orientation of the pushrods; the intake and exhaust pushrods are different lengths. Label them carefully.
4. Unbolt the cylinder heads. Because these are "torque-to-yield" bolts, they cannot be reused. Discard them immediately to prevent accidental reinstallation.
5. Lift the heads to expose the lifter yokes.

Step 4: Camshaft and Lifter Replacement

When a Hemi lifter fails, the roller bearing usually seizes. This creates a flat spot on the roller, which then acts like a chisel against the camshaft lobe. If you find a collapsed lifter, you must replace the camshaft. Installing new lifters on a scarred cam will result in a failure within 500 miles.

1. Remove the radiator, AC condenser, and front timing cover.
2. Align the timing marks to Top Dead Center (TDC).
3. Remove the timing chain and phaser, then slide the camshaft out of the front of the block.
4. Inspect the cam journals and lobes. If any lobe is rounded or scored, the "tick" was the sound of the lifter bouncing off that surface.
5. Install a new camshaft (upgrading to a non-MDS cam is common for longevity) using assembly lube with high ZDDP content.
6. Drop in new hydraulic roller lifters. Ensure the oil holes are facing the correct direction according to the service manual.

Step 5: High-Volume Lubrication System Upgrades

One of the primary causes of the Hemi tick is insufficient oil pressure at the lifter galleries during long periods of idling. To prevent the tick from returning, you must increase the volume of oil delivered to the top end.

1. Replace the factory oil pump with a high-volume unit, such as the Melling M365 or a Hellcat-spec pump. This ensures higher pressure at low RPMs.
2. Switch from the factory-recommended 5W-20 to a high-quality 5W-30 or 0W-40 synthetic oil. The slightly higher viscosity provides a better film strength to protect the roller bearings.
3. Select an oil filter with a high-efficiency synthetic media and a high bypass valve setting to ensure clean oil is always reaching the valvetrain.

Warning: If your vehicle is equipped with Multi-Displacement System (MDS), switching to a significantly heavier oil may trigger a Check Engine Light (CEL) for the solenoid circuit. Most tuners recommend a 5W-30 as the "sweet spot" for protection without triggering MDS errors.

Technical Specifications and Component Comparison

The following table outlines the critical differences between the two primary causes of the Hemi tick and the specifications required for a successful repair.

Troubleshooting Persistent Noises and Field Fixes

Even after following standard repair procedures, some owners encounter secondary noises or failures. Address these specific scenarios to ensure a quiet, reliable engine.

• The Tick Returns After Manifold Replacement

  
  
  
  • Root Cause: The heat shield is vibrating against the new bolt heads, or the manifold flange was warped beyond the gasket's ability to seal.
  • Actionable Fix: Remove the heat shield temporarily to see if the noise persists. If it does, the manifold must be surfaced by a machine shop to ensure a true flat mating surface against the cylinder head.

• Valvetrain Noise Only After Oil Gets Hot

  
  
  
  • Root Cause: Low oil pressure or aeration of the oil due to a failing O-ring on the oil pump pickup tube.
  • Actionable Fix: Check the oil pressure with a mechanical gauge. If it drops below 20 PSI at 700 RPM, the oil pump O-ring is likely pinched or hardened, allowing air into the lifter galleries. Replace the O-ring with a new Viton seal.

• Misfire Codes (P0300-P0308) Accompanying the Tick

  
  
  
  • Root Cause: The lifter has failed so severely that it is no longer opening the valve sufficiently, or the cam lobe is completely flat.
  • Actionable Fix: Perform a cylinder contribution test. If a specific cylinder shows a high misfire count and a rhythmic tick, do not drive the vehicle. Further operation will send metal shavings into the main bearings, requiring a full engine replacement.

• Short-Term "Soft" Tick on Startup

  
  
  
  • Root Cause: Hydraulic lifter bleed-down. The oil drains out of the lifter body while the vehicle sits.
  • Actionable Fix: This is often considered "normal" for Hemi engines if it lasts less than 3 seconds. Switching to an oil with high molybdenum content (like Red Line 5W-30) can help provide a "dry" lubricant layer that protects the parts during those first few seconds of rotation.

Frequently Asked Questions

Does the Hemi tick always mean the engine is failing?

Not necessarily. If the tick is caused by a broken exhaust manifold bolt, it is an external issue that does not affect the internal health of the engine, though it will decrease fuel economy and can damage the oxygen sensors. However, if the tick is internal (lifter-related), it is a "ticking time bomb" that will eventually lead to camshaft failure and potential engine seizure.

Can I fix the Hemi tick with an oil additive?

Additives containing high levels of molybdenum or friction modifiers can sometimes quiet a lifter that is beginning to stick due to carbon buildup. However, if the roller bearing has already seized or the camshaft lobe is scored, no chemical additive can repair the physical damage to the metal surfaces.

Why is the 5.7L Hemi more prone to this than other V8s?

The Hemi's lifter angle and the overhead location of the camshaft mean that the rollers do not sit submerged in an oil bath. They rely on "splash" lubrication and oil pumped through the pushrods. At idle, the oil pump flow is reduced, and the physical angle of the lifter prevents optimal lubrication, leading to heat buildup and bearing failure.

Is it worth upgrading to non-MDS lifters?

Yes, for many owners, deleting the Multi-Displacement System (MDS) is the preferred way to get rid of the tick permanently. MDS lifters have a complex internal pin mechanism that allows them to "collapse" to deactivate cylinders. This mechanism is a common failure point. Replacing them with solid, non-MDS lifters (and tuning the ECU to disable the software) significantly increases valvetrain reliability.

Professional Automotive Support

If you lack the specialized extraction tools or the equipment to pull cylinder heads, consult a certified technician specializing in SRT and Mopar platforms. Proactive mechanical intervention is the only guaranteed method to preserve the longevity of your Hemi powertrain.