Failure mode - Ram 6.4L HEMI Gasoline (Ram HD 2019+)

Exhaust manifold bolt failure / leaks (HEMI tick source #1)

Reliability tier: aggregated - verify before ordering, see /disclosure/

Symptoms

ticking at cold start that quiets as metal warms, often reported around the 60k-mile class
exhaust smell / soot trace at the manifold flange
repeat failures after bolt-only repairs (warped manifolds keep working the new bolts loose)

Compare with the other causes of the same sign on this engine: ticking, knocking, rattle or whine (3 causes)

Root cause

Cast-iron manifolds on aluminum heads: differential expansion over heat cycles shears the manifold bolts and warps the manifolds; the owner record is dense on this engine. Bolt-only repairs often repeat - the manifolds themselves are the usual replacement.

Diagnosis

listen at cold start per runner; confirm the tick warms-and-quiets (exhaust) vs constant (valvetrain)
inspect for sheared bolts and manifold flange warping before ordering hardware
replace manifolds + bolts as a set on confirmed warp

Fixes

replace manifold(s), fasteners and gaskets; both banks are conventional exhaust without aftertreatment hardware in the manifold path ()

exhaust-manifold - more than one option: 6.4L HEMI Exhaust Manifold Bolt (OEM), 6.4L HEMI Exhaust Manifold Gasket (OEM), 6.4L HEMI Exhaust Manifold Gasket, 2019-2021 (OEM), 6.4L HEMI Exhaust Manifold, left (OEM), 6.4L HEMI Exhaust Manifold, left, 2019-2021 (OEM), 6.4L HEMI Exhaust Manifold, right (OEM), 6.4L HEMI Exhaust Manifold, right, 2019-2021 (OEM)

Prevalence

common

Parts for this repair run about $30-$550: see them next to the other repairs on this engine in repair costs.