Chevrolet 1988 Light Duty Truck Repair Manual page 366

6A1-14 2.5 LITER L4 ENGINE
103
A. T im in g M a rk s
87. C ra n k s h a ft G e a r
103. T h ru s t P late B o lts
104. C a m s h a ft G ear
105. T h ru s t P late
108. C a m s h a ft
Figure 21— Camshaft and Timing Gears
CLEANING, INSPECTION, AND REPAIR
A solvent tank, large enough to hold the larger engine
parts, will be needed along with various bristle brushes
and a gasket scraper. A source of compressed air will be
helpful in the cleaning operations.
Precision m easuring tools will be required for the in­
spection procedure. These include: micrometers, cylinder
bore gage, feeler gages, dial indicator set, etc. The in­
spection work, perform ed with the proper method and
tools, is most im portant. The rebuilt engine cannot be ex­
pected to perform properly if parts worn beyond accepta­
ble limits are reused.
BLOCK
^ C lean (F ig u re 5)
1. Block (119) in solvent.
2. Block gasket surfaces.
3. C ylinder bores.
4. Oil galleries and passages.
5. Scale deposits from the coolant passages.
F-05719
y | In sp ect
1. All expansion plugs for looseness or leakage.
2. Valve lifter bores for deep scratches and varnish
deposits.
3. Block for cracks, especially in the following areas:
• C ylinder walls.
• Coolant jackets.
• Main bearing webs.
• Engine m ount bosses.
4. Main bearing bores and main bearing caps (124 and
126).
• All main bearing bores should be round and
have a uniform inside diam eter at all of the
bearing supports.
• The area where the main bearing inserts (86
and 72) contact the main bearing bore should
be smooth.
M easu re (Figure 22)
Head gasket surface distortion. Use a straight edge
and a feeler gage to check for flatness of the milled
surface at the top of the cylinder block. The surface