1. Engine Tune-Up
Procedure
(121-125)

2.  INTRODUCTION :
 WHAT DO YOU MEAN BY ENGINETUNE-UP?
- The tune-up is a routine maintenance operation which is essential for the
efficient & economical operation , as well as for long life of yours cars
engine.
- INTERVAL BETWEEN ENGINETUNE-UP.
- The interval between engine tune up should be after completion of
30,000miles (48,309km).

3. • NECESSARY TOOLS:
1). Service manual
2). Feeler gauge
3) Safety glasses & goggles
4). Spark plug socket & ratchet
5). Spark plug gauge
6). Oil , Oil filter & Oil pan
7). Screwdrivers

4. 1.Loose spark plug, start engine shut of engine &
remove spark pug.
2.Test engine compression.
3..Check the compression ratio.

5. 4.Check battery cables for damage ,corrosion &
loose connection .
5.Check intake manifold bolts for tightness to proper
specification.Even a slight leak will reduce engine
performance.
6.Check & adjust acclerator linkages.
7.Check intake manifold and air inject system.
8.Check steering system for looseness and ease of action.
9
.Ceck suspension system and shock absorber for excessive

6. PROBLEMS WHICH ARE TO BE
CHECK IN “ENGINE TUNING” UP
 PROCESS

7. *.CRANK SHAFT THUMPING
 Metallic, heavy & dull knocks which increase
in frequency.
Causeses-
1.Excessive main bearing clearance.
2.Excessive crankshaft axial play.
3.Crankshaft out of balance.
4.Low oil pressure.
5.Loose fly wheel.

8. *.CONNECTING ROD NOISE.
 1.Excessive big end bearing clearance.
 2.Insufficient lubrication.
 3.Low oil pressure.
 4.Misaligned connecting rod.
 5.Ovalized crank pin.

9. *PISTON NOISE.
 Oscillation of piston in barrel.
 More evident at low r.p.m.
“ Noise may be single out by pouring SAE
50.”
*IF NOISE IS PERSISTING THEN REPLACE THE
PISTON.

10. *PISTON PIN NOISE.
 Excessive clearance between pin and piston
bore.
 Excessive clearance between pin and bush.
 Bush loose in connecting rod small end.

11. *VALVE & TAPPET NOISE.
 Excessive tappet clearance.
 Broken valve spring .
 Excessive wear of one or more cams on
camshaft .

12. *ENGINE VIBRATIONS.
 Defective ignition.
 Defective lubrication.
 Crankshaft out of balance.
 Clutch out of balance.
 Conn-rods & piston are out of weight.
 Too stiff engine support.

13. Engine Tune up Checklist
1. Fuel Filter
2. Spark plugs
3. Car manual
4. Air Filter
5. Distributor Cap
6. Spark plug Gapping tool

14. 1.Air Filter
2.Fuel Filter
3.Fluids 4.Distributor Cap

15. Air Filter Specifications

16. Spark Plug Defects :
 Deposits
 Insulator Breakage
 Melting
 Carbon deposites

17. The correct colours for the tip and insulator
 Grayish or brown= properly burning.
 Black or wet= not firing or engine problem.

18. Spark plug replacement
 Most new engines do not require spark
plug replacement for up to (100,000
miles)

19. Types of Spark plugs

20. Tune-up safety rules to follow :
 Wear eye protection.
 Set parking break .
 Place vent hose on exhaust pipe.
 Disconnect battery.

21. Tuning Up a Jeep Engine(Sequence)

22. Clean and Check Battery
 Electrolyte level
 Specific Gravity
 Battery terminals and cable connectors
 Tightness of terminal screws
 Tightness of negative ground cable
connection
 Replacing with new one.