Shield. Heat. Exhaust. Manifold.
A Heat reflective barrier to prevent items from coming in contact with the hot Exhaust Manifold. MAN. Converter. Inner.

Exhaust Manifold Heat Shield

Fits F-250 Super Duty, F-350 Super Duty, F-450 Super Duty

6.7 LITER. F250, F350; 6.7L Diesel; Right Side. F450, F550; 6.7L Diesel; Right Side.
Exhaust Manifold Heat Shield - Repair or Replace
A tinny ticking, buzzing, or rattling noise that sounds like it's coming from under your 1991 Ford may be a bent or rusted exhaust heat shield.