
ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 13)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PM
exhaust gas flowing past the guide, creating a low pressure area. This
low pressure area draws oil into the exhaust system.
Replacement (On Vehicle)
Mark rocker arm or overhead cam components for location.
Remove rocker arm components or overhead cam components. Components
must be installed in original location. Remove spark plugs. Valve stem
oil seals may be replaced by holding valves against seats using air
pressure.
Air pressure must be installed in cylinder using an adapter
for spark plug hole. An adapter can be constructed by welding air hose
connection to spark plug body with porcelain removed.
Install adapter in spark plug hole. Apply a minimum of 140
psi (9.8 kg/cmý) to adapter. Air pressure should hold valve closed. If
air pressure does not hold valve closed, check for damaged or bent
valve. Cylinder head must be removed for service.
Using valve spring compressor, compress valve springs. Remove
valve locks. Carefully release spring compressor. Remove retainer or
rotator and valve spring. Remove valve stem oil seal.
If oversized valves have been installed, oversized oil seals
must be used. Coat valve stem with engine oil. Install protective
sleeve over end of valve stem. Install new oil seal over valve stem
and seat on valve guide. Remove protective sleeve. Install spring
seat, valve spring and retainer or rotator. Compress spring and
install valve locks. Remove spring compressor. Ensure valve locks
are fully seated.
Install rocker arms or overhead cam components. Tighten all
bolts to specification. Adjust valves if required. Remove adapter.
Install spark plugs, valve cover and gasket.
VALVE SPRING INSTALLED HEIGHT
Valve spring installed height should be checked during
reassembly. Measure height from lower edge of valve spring to the
upper edge. DO NOT include valve spring seat or retainer. Distance
must be within specifications. If valves and/or seats have been
ground, a valve spring shim may be required to correct spring height.
See Fig. 12.Fig. 12: Measuring Valve Spring Installed Height - Typical
This Graphic For General Information Only

TROUBLE SHOOTING - BASIC PROCEDURES
Article Text (p. 32)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:52PM
Loose rocker arms Retighten rocker arms,
See ENGINES
Excessive valve seat Reface valve seats, See
run-out ENGINES
Missing valve lock Install new valve lock
Excessively worn camshaft Replace camshaft, See
lobes ENGINES
Plugged valve lifter oil Eliminate restriction
holes or replace lifter
Faulty valve lifter check Replace lifter check
ball ball, See ENGINES
Rocker arm nut installed Remove and reinstall
upside down correctly
Valve lifter incorrect for Remove and replace
engine valve lifters
Faulty push rod seat or Replace plunger or push
lifter plunger rodÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄNoisy Valves Improper valve lash Re-adjust valve lash,
See ENGINES
Worn or dirty valve lifters Clean and/or replace
lifters
Worn valve guides Replace valve guides,
See ENGINES
Excessive valve seat or Reface seats or valve
face run-out face
Worn camshaft lobes Replace camshaft, See
ENGINES
Loose rocker arm studs Re-tighten rocker arm
studs, See ENGINES
Bent push rods Replace push rods, See
ENGINES
Broken valve springs Replace valve springs,
See ENGINES
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄBurned,Sticking Weak valve springs or Replace valves and/or
or Broken Valves warped valves springs, See ENGINES
Improper lifter clearance Re-adjust clearance or
replace lifters
Worn guides or improper Replace valve guides,
guide clearance See ENGINES
Out-of-round valve seats Re-grind valve seats
or improper seat width
Gum deposits on valve Remove deposits
stems, seats or guides
Improper spark timing Re-adjust spark timing
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄBroken Undersize pistons Replace with larger
Pistons/Rings pistons, See ENGINES
Wrong piston rings Replace with correct
rings, See ENGINES
Out-of-round cylinder bore Re-bore cylinder bore

WIRING DIAGRAMS
Article Text
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:53PM
ARTICLE BEGINNING
1990 WIRING DIAGRAMS
Volkswagen
Corrado
COMPONENT LOCATION MENU
COMPONENT LOCATIONS TABLEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄComponent Figure No. (Location)
A/C COMP CLUTCH ................................. 4 (D 14)
A/C SYSTEM ................................. 4 (D-E 12-15)
ABS SYSTEM ................................... 2 (B-E 4-7)
ALTERNATOR ....................................... 1 (B 3)
AUTO SEAT BELTS ............................ 7 (B-E 25-27)
BACK-UP LIGHT SWITCH ............................ 6 (E 20)
BATTERY .......................................... 1 (A 2)
BEAM SELECT SWITCH .............................. 4 (A 12)
BRAKE & PARK BRAKE INDICATOR .................... 6 (A 22)
BRAKE FLUID LEVEL WARNING SWITCH ........ 2, 6 (E 6, A 23)
CASSETTE STORAGE LIGHT .......................... 6 (E 23)
CENTRAL LOCKS ................................ 8 (A 28-31)
CIG LIGHTER ..................................... 5 (A 16)
CRUISE CONTROL SYSTEM .......................... 2 (A 4-6)
DEFOG SWITCH .................................... 6 (E 21)
DIGIFANT CONTROL UNIT .......................... 1 (C-D 3)
DOOR SWITCHES ................................... 9 (E 35)
ECS-MALFUNCTION IND LIGHT & SWITCH ............... 3 (E 8)
EMERGENCY FLASHER SWITCH ..................... 4 (A 12-14)
FOG LIGHT ........................................ 1 (C 1)
FOG LIGHT SWITCH ................................ 4 (A 15)
FRESH AIR SWITCH ILLUM LIGHTS ................... 4 (D 12)
FUEL INJECTORS ................................. 1 (D-E 2)
FUEL PUMP AFTER RUN CONTROL UNIT ................ 3 (E 11)
FUEL TANK UNIT ................................ 3 (E 9-10)
FUS #23 ......................................... 4 (D 13)
FUSE/RELAY PANEL LAYOUT .................... 8 (D-E 29-31)
FUSE/RELAY PANEL ..................... 3, 4, 5, 6 (C 8-23)
GLOVE COMPT LIGHT ............................... 6 (D 23)
HEATED CRANKCASE BREATHER ....................... 3 (D 10)
HEATED SEATS ............................... 9 (C-E 32-34)
IGNITION COIL .................................... 1 (E 3)
IGNITION SWITCH .................................. 3 (A 8)
INSTRUMENT CLUSTER ......................... 7 (A-E 24-26)
INTERIOR LIGHT DELAY SWITCH ..................... 9 (E 33)
LEFT REAR MICRO SWITCH .......................... 7 (D 25)
LEFT SEAT BELT CONTROL UNIT ..................... 7 (D 27)
LIGHT SWITCH ................................. 3 (A 10-11)
LUGGAGE COMPT LIGHT ............................. 5 (A 17)