Nissan Z - ZX 1970-1988 Repair Guide




See Figure 1

The SAE (Society of Automotive Engineers) grade number indicates the viscosity of the engine oil and thus its ability to lubricate at a given temperature. The lower the SAE grade number, the lighter the oil; the lower the viscosity, the easier it is to crank the engine in cold weather.

Oil viscosities should be chosen from those oils recommended for the lowest anticipated temperatures during the oil change interval.

Multi-viscosity oils (10W-30, 20W-50, etc.) offer the important advantage of being adaptable to temperature extremes. They allow easy starting at low temperatures, yet give good protection at high speeds and engine temperatures. This is a decided advantage in changeable climates or in long distance touring.

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Fig. Fig. 1: When choosing oil, look for the API label

The API (American Petroleum Institute) designation indicates the classification of engine oil for use under given operating conditions. Only oils designated for Service SF use should be used. Oils of the SF type perform a variety of functions inside the engine, in addition to the basic function as a lubricant. Through a balanced system of metallic detergents and polymeric dispersants, the oil prevents the formation of high and low temperature deposits, while keeping sludge and dirt particles in suspension. Acids, particularly sulfuric acid, as well as other by-products of combustion, are neutralized. Both the SAE grade number and the API designation can be found on the oil container.

Non-detergent or straight mineral oils must never be used.


See Figure 2

At every stop for fuel, check the engine oil as follows:

  1. Park the vehicle on a level surface.
  3. The engine may be either hot or cold when checking the oil level. However, if it is hot, wait a few minutes after the engine has been shut off to allow the oil to drain back into the crankcase. If the engine is cold, do not start it before checking the oil level.
  5. Open the hood and locate the dipstick, which is on the right side (passenger's side) of the engine. Pull the dipstick from its tube, wipe it clean and reinsert it.

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Fig. Fig. 2: Remove the dipstick from the tube at the side of the engine

  1. Pull the dipstick again, then while holding it in a horizontal position, read the oil level. The oil should be between the H and L marks. If the oil is below the L mark, add oil of the proper viscosity through the capped opening in the front of the valve cover.
  3. Replace the dipstick and check the level again after adding any oil. Be careful not to overfill the crankcase. Approximately one quart of oil will raise the level from L to H. Excess oil will generally be consumed at an accelerated rate even if no damage to the engine seal occurs.


See Figures 3, 4, 5, 6, 7, 8, 9 and 10

The mileage figures given in the Maintenance Intervals chart are the manufacturer's recommended intervals for oil and filter changes, assuming average driving. If your vehicle is being used under dusty, polluted or off-road conditions, change the oil and filter sooner than specified. The same thing goes for vehicles driven in stop-and-go traffic or only for short distances.

Always drain the oil after the engine has been running long enough to bring it to operating temperature. Hot oil will flow easier and more contaminants will be removed along with the oil than if it were drained cold. You will need a large capacity drain pan, which can be purchased at any store selling automotive parts. Another necessity is a container for the used oil; plastic bottles, such as those used for bleach or fabric softener, make excellent storage jugs. One ecologically desirable solution to the used oil disposal problem is to find a cooperative gas station or service facility that will allow you to dump your used oil into his tank.

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Fig. Fig. 3: Oil filter and drain plug location-1970-83 vehicles

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Fig. Fig. 4: Oil filter and drain plug location-1984-88 vehicles

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Fig. Fig. 5: Loosen and remove the oil pan drain plug

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Fig. Fig. 6: Allow the oil to drain into a suitable container

The manufacturer recommends changing both the oil and filter during the first oil change, then the filter at every other oil change. For the small price of an oil filter, it's cheap insurance to replace the filter at every oil change. One of the larger filter manufacturers points out in its advertisements that not changing the filter leaves one quart of dirty oil in the engine. This claim is true and should be kept in mind when changing your oil. Change your oil as follows:

  1. Run the engine until it reaches normal operating temperature.
  3. Raise the front of the vehicle and support it on jackstands.
  5. Slide a drain pan, of at least 6 quarts capacity, under the oil pan.
  7. Loosen the drain plug. Turn the plug out by hand. By keeping an inward pressure on the plug as you unscrew it, oil won't escape past the threads and you can remove it without being burned by hot oil.
  9. Allow the oil to drain completely, then install the drain plug. Don't overtighten the plug or you'll be buying a new pan or a "trick'' replacement plug for stripped threads.
  11. Using a strap wrench, remove the oil filter. Keep in mind that it's holding about one quart of dirty, hot oil.
  13. Empty the old filter into the drain pan and dispose of the filter.
  15. Using a clean rag, wipe off the filter adapter on the engine block. Be sure that the rag doesn't leave any lint which could clog an oil passage.
  17. Coat the rubber gasket on the filter with fresh oil. Spin it onto the engine by hand; when the gasket touches the adapter surface, give it another 1 / 2 - 3 / 4 turn-no more or you'll squash the gasket and it will leak.
  19. Refill the engine with the correct amount of fresh oil. See the Capacities chart.
  21. Check the oil level on the dipstick. It is normal for the level to be a bit above the full mark. Start the engine and allow it to idle for a few minutes.

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Fig. Fig. 7: Use extreme care when removing the filter from a recently running engine, as nearby components will be hot

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Fig. Fig. 8: Remove the oil filter using a strap wrench

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Fig. Fig. 9: Coat the gasket on the filter with clean oil

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Fig. Fig. 10: Use a funnel to pour new oil into the engine

DO NOT run the engine above idle speed until it has built up oil pressure, indicated when the oil light goes out.

  1. Turn OFF the engine and allow the oil to drain for a minute, then check the oil level. Check around the filter and drain plug for any leaks, then correct as necessary.