check engine light LAND ROVER DISCOVERY 1995 Service Owner's Manual

ENGINE
OVERHAUL21
Valve springs - inspection
1.Check free length of each spring = 46.28 mm
2.Check that end coils of each spring are square
to body of spring.Valves and guides - inspection
1.Remove carbon from valves.
2.Examine head of each valve for cracks and
burning and valve seat for pitting or burning,
replace valves as necessary.
3.Check valve seating faces for pitting, if light
pitting cannot be removed during valve
grinding operations, valves may be refaced.
CAUTION: If refacing results in valve head
stand down being exceeded, valves must
be replaced.
4.Check valve seating face angles.
Inlet = 60°00' to 60°30' - included angle =120
°
Exhaust = 45°00' to 45°30' - included angle =
90°
5.Reface or replace valves as necessary.
6.Check each valve stem for wear, measure at
each end and centre of valve stem.
Inlet = 7.96 mm
Exhaust = 7.94 mm
7.Replace any valve with stems that are worn.

ENGINE
24
OVERHAUL
3.Lightly lubricate the tool with engine oil.
4.Insert pilot into valve guide from combustion
chamber side of cylinder head until shoulder of
pilot contacts guide.
5.Check that collet is fully inserted into valve
guide and expand collet against the guide
using a suitable tommy bar.
6.Assemble the 45°cutter,MS621(exhaust
valves) and 60°cutter,MS627(inlet valves) to
toolLRT-12-501.
7.Position toolLRT-12-501and appropriate
cutter to valve seat insert to be refaced.
8.Using the Allen key, adjust position of cutter so
that centre of cutter contacts area of seat insert
to be cut.

ENGINE
OVERHAUL25
9.Cut valve seat insert using light hand pressure.
CAUTION: Remove the minimum amount
of material necessary to obtain correct
valve seat face.
10.Smear Prussian Blue to seating face of a
correctly ground valve.
11.Insert valve into guide and press it firmly,
without rotating on to seat insert, remove valve.
12.Check that an even line of Prussian Blue has
been transferred to centre of valve seat insert,
continue cutting operation as necessary until
this has been achieved.
13.Upon completion, remove all traces of swarf.Valve seat inserts - renew
1.Remove original valve seat insert taking care
not to damage cylinder head.
2.Thoroughly clean valve seat insert recess.
3.Heat cylinder head to 65°C.
WARNING: Take care when handling hot
cylinder head.
4.Place cylinder head on bed of hand press and
using a suitable mandrel, press replacement
seat insert into recess.
5.Allow cylinder head to air cool.
6.Check that seat insert is seated squarely in
recess.

ENGINE
OVERHAUL37
Inspecting components
1.Check thermostatic valve spring for distortion
and corrosion.
CAUTION: Do not separate valve from
spring.
2.Check valve for corrosion, seating faces of
valve and extension housing for damage and
pitting; replace valve as an assembly.
3.Check valve bore for corrosion. Light corrosion
must be removed from valve bore using grade
600 emery cloth soaked in oil.
4.Check oil passages in oil filter head are clear.Thermostatic valve - refit
1.Secure oil filter head in a soft-jawed vice with
thermostatic valve bore vertically upwards.
2.Lubricate a new 'O' ring with engine oil and fit
to thermostatic valve extension housing.
3.Lubricate thermostatic valve and bore with
engine oil.
4.Fit thermostatic valve and spring.
5.Position extension housing to oil filter head
ensuring that thermostatic valve is positioned
centrally in housing.
6.Fit and progressively finger tighten 2 bolts
ensuring that thermostatic valve remains
correctly positioned in extension housing.
7.Tighten bolts to 9 Nm.