DIAGNOSTIC ANALYSIS
Section 2
. . . HIGH COOLANT TEMPERATURE (Temperature
above 200° F to 210° F)
1.
Verify problem:
a.
Determine
operating
conditions
when
overheating occurs.
b.
Check temperature indicators for accuracy.
c.
Refer to guideline temperature data in the
"PERFORMANCE
DATA
GUIDELINES"
located in the rear of each Engine Section.
2.
Verify operation:
a.
Operator’s habits - running improper range.
b.
Vehicle specifications - check guideline
data if correct for vehicle and job.
c.
Accessory equipment - approved?
3.
Engine Maintenance:
a.
Clean, no oil leaks, no external coolant
leaks.
b.
Belt adjustments correct (use Krikit gauge).
Refer to the following Maintenance Manuals for belt
adjustment specifications:
Engine
Manual No.
DT-466 1
1 171 478 R1
DT/DTI-466B
1 171 562 R1
DT/DTI-466C
1 171 585 R1
400 Series OEM
1171 581 R1
9.0 Liter (All Model Years)
1171 584 R1
6.9 Liter (A Model)
1171 569 R1
6.9 Liter (B Model)
1171 577 R1
4.
Inspect Cooling System:
a.
Coolant clean and properly inhibited for
season.
b.
Radiator caps operative. Use pressure test
kit. Check restriction at water pump inlet.
Should not exceed 10 kPa (3 in Hg) without
pressure cap and engine at high idle.
c.
Hoses - correct type and properly clamped.
d.
Radiator clean and unobstructed by bent
fins, pinched tubes, etc.
e.
Radiator correct. Check repair history or
use of "stop leaks." Check specifications of
radiator for vehicle.
f.
Fan - proper specification for vehicle,
proper fit in shroud. Properly installed.
g.
Shutter control (if equipped) operative and
correct set.
5.
Inspect Engine:
a.
Water pump condition.
b.
Thermostat and seal - proper specifications
and operating correctly.
c.
Engine static timing and advance unit
operation.
d.
Oil cooler(s) proper flow both oil and water.
e.
Engine power correct.
f.
Coolant aeration from head gasket or
nozzle sleeve leakage ("Pop bottle" test).
"Pop Bottle Test"
1.
Fill bucket and pop bottle with water.
2.
Run engine until operating temperature
is reached.
3.
Immerse filled pop bottle in bucket of
water with neck facing bottom of
bucket.
4.
Insert cooling system overflow line into
pop bottle neck.
5.
Observe
pop
bottle
for
aeration
(bubbles) or in extreme cases the
water in the pop bottle will be blown
out.
NOTE: Bubbles or expulsion of water from bottle
indicate head gasket or nozzle sleeve leakage.
. . . EXCESSIVE SMOKE
1.
Excessive visual smoke can occur under two
general conditions:
a.
During acceleration.
b.
During full load operation.
2.
Smoke during acceleration can be caused by a
malfunctioning
fuel
modulator
or
improper
operation of vehicle. For example, the driver
must keep engine speed within the range
specified for the transmission and rear-end drive
ratio or intake manifold pressure will drop and
allow fuel modulator to actuate.
(400 Series, D-Series and 9.0 Liter only)
3.
If smoke under Full Load Operation is not within
recognized limits, follow the "PERFORMANCE
ANALYSIS GUIDE" CGED-390 for 400-Series
with UTDS* Model 100 Fuel Injection Pump,
CGED-365 400 C-Series with Robert Bosch
Model MW Fuel Injection Pump or CGED-335-2
for 9.0 Liter diesel engine to determine the cause
of the problem.
NOTE: A smoke sampling kit can be used to test
smoke intensity as described in Section 5. Sampling
Kit is not used on 6.9 Liter.
4.
Smoke color can indicate particular problems
a.
BLUE SMOKE - could indicate lube oil is
being burned in the cylinders.
*United Technologies Diesel Systems (formerly
AMBAC)
CGES-240-4
Printed in United States of America
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