Motorhome Exhaust Manifold and Plug Wire Failure
Posted by: Tony Howard (Tony H), Monroe WA ... thanks Tony!
Chevrolet has determined that right side exhaust manifold and right side spark plug wire failure may be the
result of inadequate air flow. This is due to the absence of a wheel-well panel on the right side front wheel
opening. This situation allows necessary engine cooling air flow to exit the engine compartment prior to passing
the exhaust manifold and spark plug wires and thereby cooling the manifold and spark wires as occurs on the left
side of the engine compartment.
This condition can be corrected by fabricating a metal panel similar to the one used on the left side of the
vehicle. Adding the panel forces the air flow to pass along the right side of the engine compartment thereby
providing a cooling effect and eliminating repeated right side manifold and spark plug wire failure.
Care must be taken in the design of the right side panel as to provide proper clearances around any hoses, wires
and engine dress items and also to provide clearance for the tire throughout its movements. The panel should extend
rearward to a point parallel to the number seven spark plug wire. The panel should be shaped and positioned
similarly to the left side panel currently installed on the vehicle. Care must be taken to leave an opening at the
rear of the engine compartment to allow cooling air to exit the engine compartment as on the left side panel.
Note...the manual includes two illustrations in this section, but they simply show air flow and don't give any
Excerpted From the Chevrolet Motor Home Chassis Service Guide 1988 edition