Chery A15. Manual — part 245

Cause Troubleshooting

method

1. Dirty spark plug or incorrect clearance

1. Clean the spark plug and reset the
clearance

2. Dirty fuel system

2. Clean the fuel system and replace the
fuel filter

3. Burned, bent or dented valve

3. Replace the valve

4. Ignition coil troble

4. Test and replace if necessary (see
relevant information on troubleshooting)

5. Trouble: engine flameout at high speed

Cause Troubleshooting

method

1. Dirty spark plug or incorrect clearance

1. Clean the spark plug and reset the
clearance

2. Ignition coil troble

2. Test and replace if necessary (see
relevant information on troubleshooting)

3. Dirty spray nozzle

3. Test and replace if necessary (see
relevant information on troubleshooting)

4. Dirty fuel system

4. Clean the fuel system and replace the
fuel filter

6. Trouble: abnormal noise of valve

Cause Troubleshooting

method

1. Incorrect engine oil level in
the crankcase

1. Check and correct engine oil quantity

2. Incorrect engine oil viscosity

2. Choose the engine oil of proper viscosity

3. Low engine oil viscosity

3. (a) Replace the engine oil and filter

(b) Run the engine to normal working conditions
(c) Replace the engine oil and filter again

4. Engine oil under pressure

4. Check and correct the engine oil level

5. Dirty tappet

5. Replace the rocker arm and hydraulic tappet
assembly

6. Worn-out rocker arm

6. Check the oil supply circuit of the rocker arm

7. Overused tappet

7. Fix new rocker arm and hydraulic tappet assembly

8. Worn-out valve conduit

8. Replace the cylinder cover

9. Worn-out valve seat

9. Grind the valve or replace the cylinder cover

10. Failing rocker arm adjustor

10. Replace the rocker arm/hydraulic tappet assembly

7. Trouble: abnormal noise of the connecting rod

Cause Troubleshooting

method

1. Insufficient engine oil

1. Check the engine oil level

2. Engine oil under pressure

2. Check the engine oil level, engine oil pump, safety
valve and spring

3. Under viscosity of engine oil

3. Add engine oil of proper viscosity

4. Over viscosity of engine oil

4. (A) Replace the engine oil and filter

(B) Run the engine to normal working temperature
(C) Replace the engine oil and filter again

5. Excessive bearing clearance

5. Measure bearing clearance and repair

6. Bluntness of the connecting
rod shaft collar of the crank

6. Replace the crank shaft or grind the surface

7. Vibrating connecting rod

7. Replace the connecting rod

8. Trouble: abnormal noise of the main bearing

Cause Troubleshooting

method

1. Insufficient engine oil

1. Check the engine oil level

2. Engine oil under pressure

2. Check the engine oil level, engine oil pump, safety
valve and spring

3. Under viscosity of engine oil

3. Add engine oil of proper viscosity

4. Over viscosity of engine oil

4. Change engine oil viscosity
(A) Replace the engine oil and filter

(B) Run the engine to normal working temperature
(C) Replace the engine oil and filter again

5. Excessive bearing clearance

5. Measure bearing clearance

6. Worn-out thrust bearing

6. Replace the thrust bearing

7. Bluntness of the crank shaft

7. Replace the crank shaft

8. Loosened flywheel

8. Screw tight the bolts

9. Trouble: decreased engine oil pressure

Cause Troubleshooting

method

1. Insufficient engine oil level

1. Check the engine oil level

2. Engine oil pressure switch

2. Install new engine oil pressure switch

3. Under pressure of the engine
oil

3. Check the main bearing clearance

4. Clogged engine oil filter

4. Install new engine oil filter

5. Overused engine oil pump

5. Replace the engine oil pump and worn-out parts

6. Under viscosity of the engine
oil

6. Add engine oil of proper viscosity

7. Engine oil pump safety valve

7. Unfix the valve, check the clearance and replace

8. Loosened suction pipe of the
engine oil pump

8. Unfix the crankcase oil tray and fix new pipe or
over clearance

9. Deformed or cracked engine
oil pump cover

9. Fix new engine oil pump

10. Excessive bearing clearance

10. Measure bearing clearance and repair

10. Trouble: engine oil leakage

Cause Troubleshooting

method

1. Damaged gasket

1. Replace the gasket

2. Loosened fittings and leaked
or damaged metal parts

2. Repair or replace the parts

3. Worn-out engine oil pump
bolts

3. Replace

11. Trouble: burning engine oil or accumulated charcoal on spark plug

Cause Troubleshooting

method

1. PVC system trouble

1. Check the system and repair the exhaust control

2. Worn-out or dilapidated
piston ring

2. Fix new piston ring

3. Accumulated charcoal on
piston ring groove

3. Fix new piston ring

4. Overtight piston ring in the
groove

4. Take out the piston ring and check. Replace the
piston if it is overtight.

5. Worn-out valve conduit

5. Replace the cylinder cover

6. Damaged valve sealing

6. Replace the sealing parts

Three. Troubleshooting on the cylinder compression pressure

The purpose of testing the cylinder pressure is to identify the troubles of some particular
cylinder. However, the prerequisite is that the storage battery and starter must be in the
normal working mode, or the precision of cylinder pressure measurement will be affected.
(1) Check the engine oil level and add engine oil if necessary.
(2) Start up the car until the engine working temperature is reached. Run the car on an
even road and accelerate the engine for a couple of minutes.
Note: please use special tools (Figure 3) to protect the spark plug conduit when the
spark plug is being taken out.
(3) Take out all spark plugs; check if they suffer any mechanical troubles, overheating
and oil smears and record the cylinder number of the spark plug.














(4) Take out Fuse 7 and 8 off of the engine from the relay box in the front cabin.
(5) Fix the special tool for the pressure gauge fittings into the spark plug hole.
(6) Start the engine until the vacuum gauge reading is at the maximum and record the
pressure of the first cylinder.
(7) Repeat the above procedure and record the pressure values of the remaining cylinders
(8) The pressure value shall not be lower than 689KPA (100PSI) and the pressure of each
cylinder shall not differ from each other by over 25%.
(9) If one or several cylinder pressure values are improper, repeat the above pressure test.
(10) If the pressure value of any cylinder is still lower than the standard value, there must
be something wrong with the cylinder. Measuring cylinder pressure only provides a
reference to engine troubleshooting. To identify the troubles, it is still necessary to
disassemble the engine to find if the cause is under pressure of cylinder.








Four. Cylinder compression pressure leakage test