The "Hemi tick" has become almost legendary among Mopar owners. Your 2019 Grand Cherokee's 5.7L Hemi makes a ticking sound, and you're trying to determine if it's the harmless exhaust manifold tick or something more serious requiring attention.
Types of Hemi Tick
Exhaust manifold tick (common, usually harmless):
- Loudest when cold, fades when warm
- Sounds like it's from the engine sides
- Doesn't change with oil pressure
- Caused by broken manifold bolts
Lifter/cam tick (more serious):
- Continues when engine is warm
- May change with RPM
- Often gets worse over time
- Caused by worn or failed lifters
The Exhaust Manifold Issue
The Hemi's exhaust manifold bolts are known to break due to heat cycling. When broken, exhaust gases leak at the manifold-to-head junction, creating a ticking sound. This is common enough to be considered almost normal, but it can:
- Trigger exhaust smell in cabin
- Cause check engine light (exhaust leak affects O2 sensor)
- Worsen over time as more bolts break
Lifter/Cam Issues
More recent 5.7L Hemis have experienced lifter and cam failures. Warning signs include:
- Tick that persists when warm
- Progressively worsening noise
- Misfires accompanying the tick
- Check engine light with misfire codes
Diagnosis
- Note if tick fades when warm (suggests exhaust leak)
- Listen with stethoscope to isolate location
- Check for exhaust smell near manifolds
- Scan for any misfire codes
- Oil analysis can detect metal from lifter wear
Repair Costs
- Exhaust manifold bolt repair: $300-$800
- Exhaust manifold replacement: $500-$1,200
- Lifter replacement: $2,000-$4,000
- Cam and lifter replacement: $3,000-$6,000