HEXA

ENGINE



Connect compression tester to adapter and

tighten vent knob.



Crank the engine with starter motor by

200-

350

rpm approximately. Pressure gauge

needle will start rising. Continue cranking till

gauge needle stops rising any further. Note

down the reading. Loosen vent knob to

make sure the tester needle returns to zero.

Repeat this operation for remaining

cylinders.



Minimum compression pressure in each

cylinder should be

23 ± 1

bar.



Low compression pressure may be due to

leakage past valves / piston rings / blown

cylinder head gasket. To ascertain the point

of leakage, spray small quantity of clean

engine oil in to cylinder showing low

pressure. If it improves, wear in piston rings

/ cylinder bore is indicated. If it does not,

leakage past the valves is indicated. If

compression pressure of adjacent cylinder

is also on lower side and equal, it may be

due to blown cylinder head gasket.

Fuel System :

Check the Fuel system for fuel flow. If the

flow is restricted change the filter/ rectify the

defect. Check for any kink or blockages in the

fuel lines. Check “Water in fuel indicator” in

the instrument cluster, if illuminated drain the

water from the sedimentor.

Clutch Slippage :



Clutch slipping can be confirmed by any of

the following two methods:



Drive the vehicle with normal load in

3rd

gear

on level ground and let the speed drop

down to approximately

15 kmph

. Now

press accelerator pedal fully. With slipping

clutch the vehicle speed will not pick up and

also clutch burning smell will be noticed. If

this does not occur and vehicle picks up

speed, it indicates that clutch does not slip.

Brake Binding :



During driving apply brakes number of times

and then shift gear to neutral position and

check free rolling of vehicle. Check brake

drums/brake discs for overheating and if

necessary jack up the vehicle and check

wheels for free rotation.

ii.

Excessive Engine Oil Consumption :

High engine oil consumption may also

lead to overhauling of the engine but before

proceeding to overhauling, check following points:



Make sure that there is absolutely no

external oil leakage i.e. from the camshaft

oil seal, crankshaft oil seal, oil sump gasket,

oil pump gasket, cylinder head cover

gasket, turbocharger oil feeder and return

lines etc.



Ensure that the oil separator in the cylinder

head cover is properly mounted.



Check that no excessive oil found in the

intercooler piping and OMS is functioning

properly.



If no external leakage is found, determine

the exact engine oil consumption, as per

following procedure.

Determining Exact Engine Oil Consumption :

CAUTION



Do not make a rough estimate of engine oil

consumption by noting the kilometers

covered by the vehicle at any random stage

and finding oil consumed from the topped

up position taking into consideration

dipstick level and oil sump capacity.

Procedure :

1. Once it is doubted that engine oil

consumption is higher, place the vehicle on a

level ground.

2. Ensure oil level in dipstick in its max position

(Oil Qty –

7.5L

3. Warm up the engine so that oil temperature is

75º- 80º C

4. Take a clean vessel; place it below the drain

plug of oil sump.

5. Drain the hot oil into the clean vessel. Drain it

fully.

6. Screw in oil sump drain plug and tighten it.

7. Weigh the vessel along with oil. Let this

weight be ‘w1’ gms.

8. Refill the weighed oil into the oil sump. Do not

spill any oil. The vessel used for draining

should not be used for any other purposes.

9. Drive the vehicle approx.

200 - 300 km

. This

drive should include at least

30 - 40 kms

. of

highway or similar road, vehicle running at

about 60 kmph.

10. Let this drive distance be ‘D’ kms.