Check Engine Oil Level

3. Check Engine Oil Level

• Check for contaminants (fuel, coolant)
• Correct grade/Viscosity
• Miles/Hours on oil, correct level
• Check level in reservoir

Method	Check
Visual

Purpose

To determine if there is enough oil or oil of sufficient quality to operate the injectors.

Test Procedure

Check oil level with oil gauge when vehicle is on level ground. If there is no oil or very little oil in the crankcase, the injectors will not operate.

If the oil level exceeds the recommended amount, it is possible the engine was incorrectly serviced or fuel is diluting the oil and filling the crankcase. Usually if a substantial amount of fuel is in the oil, the oil will have a fuel odor.

Inspect oil for color. A milky white oil indicates possible coolant contamination and will have an ethylene glycol odor.

Check service records for correct oil type and viscosity for the vehicle operating temperature. Single grade or 15W 40 oil is recommended for cold ambient temperatures. Oil that has had extended drain intervals will have increased viscosity (become thicker) and will make engine cranking more difficult and starting less reliable at temperatures below freezing. Refer to the lube oil chart below to select the correct (viscosity) oil to use for the temperature condition(s) the engine will be operating in. Use CG-4/SH rated oil.

Figure 2. — Lube Oil Chart

The oil level reservoir should also be checked. Remove the inspection plug in top of reservoir (Figure 3.) and check to see if the oil level in the reservoir is within one inch from the bottom of the inspection plug. (A reservoir that drains back after the engine has not been operated for a period of time can cause a hard start and stall condition.) Filling the reservoir will allow the system to prime faster, thereby facilitating starting.

Possible Causes

• Oil level low — Oil leak, oil consumption, incorrect servicing.
• Oil level high — Incorrect servicing, fuel dilution from lift pump, fuel dilution from loose injectors.
• Oil contamination with coolant — Oil cooler, head gasket, porosity.
• Low reservoir level — Engine built dry (not pressure lubed), prolonged period of not running, leaking check valve in high pressure pump (1994-95 model years only). Excessive cranking without starting.

Tools Required

1/4 inch drive ratchet or breaker bar to remove inspection plug.