- Visual/Physical Underhood Inspection

Inspection

One of the most important checks is a visual underhood inspection. This can often fix a problem. Inspect all vacuum hoses for pinches, cuts, or disconnects. Inspect all the wires in the engine compartment for good connections, burned or chaffed spots, pinched wires, or contact with sharp edges or hot exhaust manifolds. These quick tests take only a few minutes, can save you valuable time, and help you repair the problem.

All Powertrain diagnosis should begin with a thorough visual inspection. Visual inspection can often lead to repair of a simple problem without use of the tables.

^ Inspect all vacuum hoses for being pinched, cut, disconnected or misrouted. The EVAP Purge Solenoid vacuum hoses can easily be installed incorrectly. Be sure to inspect hoses that are difficult to see such as beneath the upper intake, generator, etc.

^ Check for proper ground connections, ground eyelets connected to ground points, star washers installed, if applicable.

^ Check the battery positive junction block for loose retainer nuts.

^ Inspect other wiring in the engine compartment for good connections, burned or chaffed spots, pinched wires or harness contact with sharp edges or hot exhaust manifolds.

^ Check for blown or missing fuses and for relays missing or installed in the wrong locations.

^ Inspect plug wires for proper routing, connection, cuts, visible signs of arcing to ground.

Several of the symptom procedures call for a careful Visual/Physical. It can lead to correcting a problem without further checks and can save valuable time. This check should include the following items:

^ PCM grounds for being clean, tight, and in their proper location.

^ Vacuum hoses for splits, kinks, and proper connections, as shown on Vehicle Emission Control Information label. Check thoroughly for any type of leak or restriction.

^ Air intake ducts for collapsed or damaged areas.

^ Air leaks at throttle body mounting area, Mass Air Flow (MAF) sensor and intake manifold sealing surfaces.

^ Ignition wires for cracking, hardness, proper routing and carbon tracking.

^ Wiring for proper connections, pinches and cuts.