← Back

Recipe - GM 8.1L / 6.0L Vortec Gasoline (HD 2001-2007, Express/Savana vans incl.)

Specific Fix build

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

Cold-start tick on a 6.0L or 8.1L GMT800 HD gas truck: find the leaking manifold flange before blaming lifters or injectors, then extract the sheared studs and refit bolts and gaskets (mode Exhaust manifold bolt breakage (cold-start tick)).

Parts

• gm-hd-gas-vortec: exhaust-manifold-bolt (honest catalog gap) - manifold bolts (catalog gap - source locally) (qty 1)
• gm-hd-gas-vortec: exhaust-manifold (honest catalog gap) - manifold, only if warped (catalog gap) (qty 1)

Install order

1. listen for the tick at the manifold on a cold engine (hose-listen) before condemning lifters or injectors
2. inspect for sheared or loose bolts at the flange, rear first (driver's side rear is the commonly reported first)
3. extract broken studs, chase the threads, fit new bolts (owners commonly upgrade to locking-style) and gaskets
4. check the manifold flange for warp; replace it if it will not seal

Expected outcome

No tick at cold start, no exhaust smell under the hood.

Do not

• do not leave a ticking leak - it can warp the manifold and burn the gasket

DIY or shop: Shop job