Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car

Audi 80/Avant
+ Technical specification
- Engines
   Basic elements
   Lubrication system
   Ventilation of a case
   Visual check of the engine
   Running in of the new engine
   Engine service life
   Nominal and maximum frequency of rotation
   Restriction of frequency of rotation
   Measurement of pressure of compression
   List of malfunctions
   Provorachivaniye of the engine
   Hydraulic pushers
   Works on the GRM gear belt
   List of malfunctions
   Removal and installation of a head of the block of cylinders
   Removal and installation of the engine
+ System of production of the fulfilled gases
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

List of malfunctions

Too low pressure of compression

Evenly low pressure of compression not necessarily is a disturbing sign; also measuring admissions of various control devices can be the cause. However it is worth reflecting if between separate indicators of cylinders differences more than 2 — 3 bars are measured. It can mean:

  • Wear of pistons and piston rings.
  • Coking up of piston rings because of formation of deposits.
  • Development (ovality) in cylinders as a result of jamming of pistons.
  • Deposits on cores or saddles of valves because of the remains of combustion or oil.
  • The burned-down valves. In most cases leaky adjacent valves are the reason of insufficient pressure of compression and, thereby, the reduced engine capacity. It is possible to help trouble only capital repairs of a head of the block of cylinders.

Search of malfunctions

More precisely to define malfunction with a low pressure of compression (a low compression), it is necessary to apply the following cunning: to dig in an opening for a spark plug it is a little oil from a butterdish and once again to measure pressure.

  • If indicators still low, the reason – valves.
  • If you received higher rates, piston rings are the reason or, it is possible, as well cylinders. The added oil created for a short time the best consolidation between pistons and walls of cylinders so the compressed gas almost could not disappear from there.

Test of system for tightness

More exact results can be received after check of system on tightness which some workshops can carry out. For this purpose compressed air is directed to the combustion chamber through openings of spark plugs.

If the checked combustion chamber loses pressure, it can be seen on a scale of the control device. Rather big place of leak can be distinguished listening:

  • Blares near a branch pipe of an exhaust pipe indicate the leaky final valve.
  • If air leaves the case of the air filter, so the inlet valve is faulty.
  • In case of defective laying of the block of cylinders or a crack in a head of the block of cylinders compressed air comes to light from the next opening of a spark plug or from an open broad tank with cooling liquid.
  • Worn-out walls of cylinders, mirrors of cylinders or piston rings pass air in a case, from where it leaves through open branch pipes for a nalivaniye of oil or on the directing tube of the oil probe.