How many quarts do I need to change the oil in my Nissan Maxima 1990 6cl?

5.1 Quarts with Filter change.

Try 4 quarts and start the engine to fill the filter. Shut engine off, wait 15 minutes for the oil to go back to the pan, then check the oil dipstick. If it's low, put in another quart.

shifts are you meaning the auto box gearbox ? if it is when was the oil last changed ?

If you drained the torque converter 6 or 7 quarts. If not about 4 quarts. Best to start out with 3 start the car and add from there.

a quart in 1000 miles is not excessive, no leaks?? then its going out the tailpipe, could be valve seals or rings,

It may take between 4 and 5 quarts. There is a oil cap usually located at the valve cover. You really should not attempt anything on this engine, if you are not familiar. A little mistake can cause thousands of dollars ,damage.

Fuel tank, 17.2 gallons. Radiator capacity, 1.25 gallons. Oil capacity 4.5 quarts with the filter. Oil pressure, 20-50 psi.

Approximately 2.5 quarts of Nissan Manual Transmission Fluid (MTF) HQ Multi 75W-85 oil (P/N 999MP-MTF00P) is required.

Check out this link for more info on changing the fluid and fluid options: http://www.greghome.com/Greg's%2...axSE/MT-90.htm

Hope this helps, Randy

Park the car on a level surface, let the engine warm up, Locate the engine-oil pan under the car, and remove the drain-plug. Put a container under the oil-pan to collect the old oil. Remove the oil-filler cap on top of engine head-cover. Remove the oil-filter by the engine block. You could grab it with one hand and turn counter-clockwise. While waiting all oil to drain out, smear some new engine oil on the new oil-filter 'o'-ring, and screw it back in place. Tighten 3/4 turn after the o-ring hits the engine surface.
Clean the drain-plug with a clean rag and tighten back in place-not over-tighten it!. Put back about 3-quarts of new engine oil through the oil-filler cap, and hand tighten the cap. Start the engine and look for leaks. After a few hours later, check the oil level. You are done!

Replace your valve covers do to clogged pcv piping