An exhaust manifold leak often starts as a ticking noise on a cold start that fades as the metal expands. Over time the leak usually gets worse.
Symptoms
- Ticking on cold start that quiets when warm.
- Black soot marks at the manifold flange.
- Exhaust smell in the engine bay or cabin.
- Upstream oxygen sensor readings affected by the leak.
Why Studs Break
- Repeated heat cycles and manifold expansion.
- Corrosion between the stud and the head.
- Warped manifold flanges that keep stressing the studs.
Repair Tips
- Soak fasteners with penetrating oil and use heat carefully.
- Extract broken studs without damaging the head threads.
- Check the manifold flange for warpage and machine or replace it.
- Use new gaskets, studs and nuts, and tighten from the center outward.
Evergreen Parts
Evergreen offers gasket sets and seals identified by engine or vehicle application. Use the Evergreen eCatalog to find the right part, and see where to buy Evergreen through our authorized distributors.
