Jeep Grand Cherokee

1993-1999 of release

Repair and car operation



Jeep Grand Cherokee
+ Cars of mark Jeep Grand Cherokee
+ Options and routine maintenance
+ Рядный the six-cylinder engine
+ Engine V8
- Procedure of the general and engine major repairs
   The general information
   Engine major repairs - the general information
   Check компрессионного pressure in cylinders
   The diagnostic checks made by means of the vacuum gauge
   Methods of removal of the engine and necessary safety measures
   Removal and engine installation
   Variants of restoration of the engine
   Order of dismantling of the engine
   Dismantling of a head of cylinders
   Cleaning and check of a condition of a head of cylinders
   Service of valves
   Assemblage of a head of cylinders
   Removal of shatunno-piston assemblages
   Removal of a cranked shaft
   Cleaning of the block of the engine
   Check of a condition of the block of the engine
   Хонингование cylinders
   Check of a condition of shatunno-piston assemblages
   Check of a condition of a cranked shaft
   Check of a condition radical and шатунных bearings
   Assembly order of the engine after end of its major repairs
   Installation of a cranked shaft and check of backlashes of radical bearings
   Installation of piston rings
   Installation of shatunno-piston assemblages and check of backlashes in шатунных bearings
   The first start of the engine after major repairs
+ Systems of cooling, heating and air conditioning
+ The power supply system and release of the fulfilled gases
+ System of an electric equipment of the engine
+ Systems of decrease in toxicity of the fulfilled gases and engine management
+ Manual box of a gear change
+ Automatic transmission
+ Distributing box
+ Coupling and трансмиссионная a line
+ Brake system
+ Suspension bracket and steering
+ Body
+ System of an onboard electric equipment
+ Controls and operation receptions




The diagnostic checks made by means of the vacuum gauge

Measurement of depth of depression gives the valuable information on a condition of internal components of the engine. There is a possibility to estimate degree of deterioration of piston rings and walls of cylinders, to reveal leaks of a head of cylinders and the inlet pipeline, infringement of passableness of system of release of the fulfilled gases, jamming or a burn-out of valves, easing клапанных springs, infringement of installation of a corner of an advancing of ignition or distribution of operation of valves, and other problems with ignition.

Unfortunately results of vacuum testing are easily wrong for interpreting, therefore it always should be made together with other checks, the general which analysis of results allows to draw unequivocal conclusions.

For an adequate situation assessment are important both absolute indications of the vacuum gauge, and relative size of a deviation of an arrow of the device. The majority of vacuum gauges measure depth of depression in mm (inches) of a mercury column (more low all results and indicators will be given in metric system). All given below the reference become on the basis of the assumption of check carrying out at zero height concerning a sea level. Lifting of a point of carrying out of check (or decrease in atmospheric pressure) conducts to corresponding decrease in instrument readings. For a binding we will notice that the increase in height of a point of carrying out of tests at each metre after a mark in 610 m gives result understating on 83 mm hg

Connect the vacuum gauge directly to the entrance union of the inlet pipeline - not to port of the case of a throttle. Track, that no hoses during check remained disconnected is will lead to infringement of reliability of results.

Before starting check allow to the engine to be warmed up completely. Block (wedges) of a wheel and cock a lay brake. Having translated transmission in position Р, start the engine and leave its working on turns of normal idling.

Before starting the engine attentively examine fan blades on presence of cracks and other damages. Watch that during procedure performance not to touch the fan and not to suppose contact to it of vacuum hoses. After engine start it is not necessary to become directly in front of the car or in a plane of rotation of the fan.

Consider vacuum gauge indications; for the inquiry, on the average, the serviceable engine should create depression by depth from 431 to 559 mm hg At stable position of an arrow of the device. Results of check can are interpreted as follows:

 PERFORMANCE ORDER

  1. The stable low indication of the vacuum gauge usually speaks infringement of integrity of a lining between the inlet pipeline and the throttle case, presence of "leaks" of vacuum hoses, delay of the moment of ignition or infringement of distribution of operation клапанного the mechanism (camshaft). By means of a stroboscope check up installation of a corner of an advancing of ignition, then spend all diagnostic checks listed in the given Chapter before to start removal of a cover of a distributive chain and check of correctness of combination of distributive labels.
  2. If instrument readings below norm on 75 - 200 mm hg also are astable at this level, the probability of presence of leaks through a lining of the inlet pipeline around an arrangement of inlet port or malfunction of an injector of fuel is great.
  3. If the arrow of the device regularly falls on 75 - 100 mm hg, stably being kept on these values, it is possible to suspect leak of valves. Make check компрессионного pressure or testing of the engine for leaks.
  4. Irregular falling or arrow deviations can be caused jamming of the valve or ignition admissions. Make check компрессионного pressure or testing of the engine for leaks, also check up spark plugs.
  5. Frequent trembling of an arrow at level about 100 mm hg at engine work on the single turns, accompanied by the filled with smoke exhaust speaks about deterioration of directing plugs of valves. For acknowledgement of the given assumption make testing of the engine for leaks. If trembling arises at increase of turns of the engine, check up on leaks a lining of the inlet pipeline or a head of cylinders, estimate easing degree клапанных springs, whether make sure valves have burnt through and whether take a place ignition admissions.
  6. Insignificant fluctuations within 25 mm upwards-downwards can testify to presence of problems with ignition. Make all usual options, in case of need start the engine for work with the ignition analyzer.
  7. In case of an essential deviation make check компрессионного pressure or testing of the engine for leaks for check of degree of deterioration or failure of cylinders or infringements of integrity of a lining of a head.
  8. If the arrow of the vacuum gauge slowly "walks" in a wide range, whether check up the system of operated ventilation картера (PCV) is corked, estimate quality of a toplivno-air mix and also check up on presence of signs of leaks of a lining of the case of a throttle/carburettor and the inlet pipeline.
  9. Make check on slow restoration of indications after "revival" of the engine by fast opening throttle заслонки and отпускания it after lifting of frequency of rotation of a cranked shaft in 2500 rpm. Usually indications should fall practically to zero, rise above norm (approximately on 130 mm hg) and then to return to former value. If depth of depression is restored slowly and does not form peak at closing throttle заслонки, it is possible to speak about deterioration of piston rings. If the considerable delay takes place, check up passableness of system of release of the fulfilled gases (often it appears is blocked the muffler or каталитический the converter). Such assumption most easier to check up having disunited sections of system of release of the fulfilled gases above a place of prospective corking.