Nissan Maxima QX

since 1993 of release

Repair and car operation

Nissan Maxima QX
+ Nissan Maxima brand Cars
+ Maintenance instruction
+ Settings and routine maintenance
- Engine
   + SOHC Engines
   + DOHC Engines
   - General major maintenance of the engine
      General information
      Check of pressure of oil
      Check of kompressionny pressure in cylinders
      Diagnostics of a condition of the engine with use of the vacuum gage
      Alternative versions of schemes of regenerative repair of the engine
      Removal of the power unit from the car - preparation and precautionary measures
      Removal and engine installation
      Order of dismantling of the engine by its preparation for major maintenance
      Dismantling of a head of cylinders
      Cleaning and check of a condition of a head of cylinders
      Service of valves
      Assembly of a head of cylinders
      Removal of shatunno-piston assemblies
      Removal of a cranked shaft
      Cleaning of the block of the engine
      Check of a condition of the block
      Honingovaniye of mirrors of cylinders
      Check of a condition of components of shatunno-piston group
      Check of a condition of a cranked shaft
      Check of a condition and selection of loose leaves of radical and shatunny bearings of a cranked shaft
      Check of a condition of camshafts, pushers of valves and bearings
      Engine assembly order
      Installation of piston rings
      Installation of a cranked shaft and check of working gaps of radical bearings
      Installation of a back epiploon of a cranked shaft
      Installation of shatunno-piston assemblies and check of size of working gaps in shatunny bearings of a cranked shaft
      Trial start and engine running in after major maintenance
+ Systems of cooling, heating
+ Power supply system and release
+ engine Electric equipment
+ Control systems of the engine
+ Transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


Check of a condition of components of shatunno-piston group


1. Previously shatunno-piston assemblies should be carefully cleared. Rings are necessary for removing from pistons.

Piston rings are subject to replacement without fail.

2. By means of the special adaptation remove rings from pistons, - try not to damage walls of the last casually.
3. Scratch out from the bottoms of pistons traces of coal deposits. After removal of the main layer of deposits smooth out a surface manually a wire brush or a piece of a fine-grained emery paper.

At all do not use for cleaning made of a soft material and pistons easily subject to an erosion wire nozzles to an electrodrill!

4. By means of the special adaptation clean flutes under installation of rings on pistons. It is alternatively possible to use for this purpose a fragment of an old piston ring, however be careful, - do not scratch a bottom and walls of a flute and do not cut fingers.

5. Having removed the main deposits, wash out shatunny assemblies by solvent and carefully dry them, whenever possible with application of the compressed air. Check passableness of maslovozvratny openings in back walls of flutes under installation of piston rings, and also oil openings in the bottom heads of rods.

When using the compressed air do not forget to put on goggles!

6. If walls of pistons and a mirror of cylinders are not damaged and excessively are not worn-out, and the block of the engine was not pierced and not replaced, need for replacement of pistons also disappears. Normal wear of pistons is shown in the form of vertical traces of development on a persistent surface and a small weak point of landing of the top kompressionny ring in the flute. Do not forget that replacement of piston rings is made without fail, regardless of their condition.
7. Attentively examine each of pistons on existence of cracks in a skirt, round ledges under installation of piston fingers and around an arrangement of rings.
8. Check persistent surfaces of a skirt of the piston on existence of scratches, the bottom - on existence of through openings and прогаров on edge. Presence of scratches on a skirt can be regarded as a sign of long overheats of the engine, or too early ignition of an air and fuel mix, - check serviceability of functioning of system of cooling. Progara along the edges of the bottom are the detonation certificate. In any case, the reason of the revealed violation should be eliminated in order to avoid recurrence. As the possible reasons of formation of the listed defects leakages of soaked-up air, the wrong configuration of an air and fuel mix, violation of installation of a corner of an advancing of ignition, the wrong functioning of systems of ignition and EGR can act also.
9. Dot corrosion of pistons in the form of cavities speaks about hit in chambers of combustion and/or a case of the engine of cooling liquid. Besides, take care, that the reason of internal leaks was eliminated.

10. Estimate size of a lateral gap of landing of piston rings in the flutes for what enclose a new ring outside in the flute on the piston and shchupy lezviyny type measure a remaining gap. Repeat measurement in two-three points on flute perimeter. Watch to mixing kompressionny rings, - top differs from the second. If the size of a gap exceeds admissible value (see. Specifications), pistons are subject to replacement.

11. Define a landing gap of pistons in the cylinders for what measure diameters of the last (see. The section Check of a condition of the block) also subtract from them diameters of the corresponding pistons. Measurement of diameter of the piston is made on a persistent surface at an angle 90 ° to an axis of a piston finger and on the set removal from the bottom. If the landing gap of the piston in the cylinder exceeds admissible value (see.), the block it is necessary to give specifications to a pro-point with a selection of new pistons and piston rings of repair diameter.

12. Estimate correctness of landing of pistons on rods, having tried повращать components in opposite directions. Existence a little appreciable люфта speaks about excessive wear of a joint. For situation correction it is necessary to deliver shatunno-piston assemblies in a car-care center workshop where necessary regenerative repair and replacement of fingers will be made.
13. Performance of procedure of removal of pistons from rods (in case of such need) also should be entrusted to specialists of car-care center. In parallel, rods can be checked on existence of signs of a bend, twisting and other deformations with use of the special diagnostic equipment.

Needlessly it is not necessary to remove pistons from rods.

14. Check rods on existence of cracks and other mechanical damages. Temporarily remove covers of the bottom heads, take loose leaves of old bearings, wipe beds in covers and heads and check them on existence of agnails, задиров and roughnesses. Having finished check, enclose loose leaves into place, establish covers on the bottom heads of rods, and by hand tighten fixing bolts.

If the engine is under repair for the purpose of elimination of knock of fingers, replace shatunny assemblies.