This document summarizes a case study on an engine tripping problem in an engine used at XYZ Resources Ltd. due to seasonal temperature variations. During training, the author observed the G3412TA engine would frequently trip without warning on hot days, shutting down the plant for 1.5 hours. Potential causes investigated included high ambient temperatures, insufficient coolant flow, and faulty sensors. The document concludes the problem is likely caused by high inlet air temperatures and insufficient coolant flow. It recommends installing a better engine room ventilation system per Caterpillar guidelines to address high temperatures as a solution.

1. Case study on engine tripping problem in
engine due to seasonal temperature variation
Ganesh Chouhan1
1Department of Mechanical Engineering, Vidhyadeep
institute of management and Technology, Anita,Kim,
India. (ganesh_chouhan31@yahoo.com)
In XYZ Resources Ltd. numbers of internal combustion
engines are used. Most of those engines are four stroke
engines working on Otto cycle in which natural gas is used
as fuel. All the engines in XYZ are made by Caterpillar
Inc. and each has some distinct functions to perform.
While going under training at XYZ, we found a problem
in an engine called G3412TA made by Caterpillar Inc.
G3412TA, found in Dew Point Control Unit is used for
circulation of propane for cooling purpose. But the
problem with this engine is that it trips without any
tripping warning specially in hot days it trips frequently
and hence the plant has to be shut off for at least one and
half hour. Thus the problem proves very uneconomic for
company. During the whole curriculum we examined and
evaluated the problem and tried to rectify the feasible
solutions for the same.
Keywords: manifold, combustion, cooling
system, exhaust gas.
I. INTRODUCTION
There may be problem in any component of the cooling
system. The component involved in cooling system of
the engine is radiator; radiator cooling fans, water
pump, engine block, thermostat, hoses, etc. Various
sensors are provided for measuring the various
parameters like temperature of the coolant, level of the
coolant, pressure at the outlet of the water pump. These
sensors sense respective parameter and sends
information about them to the ECM. Engine has some
tripping parameters. If any of them fullfill tripping
condition, engine will automatically trip. These tipping
points are sets for secure the parts of engine, plant
assets, workers life.
A. Purpose of cooling system
As fuel is burned in the engine, about one-third of the
energy in the fuel is converted into power. Another
third goes out the exhaust pipe unused, and the
remaining third becomes heat energy.
1. A cooling system of some kind is necessary in any
internal combustion engine. If no cooling system were
provided, parts would melt from the heat of the burning
fuel, and the
Tushar N. Desai2
2Department of Mechanical Engineering, S.V.
National Institute of Technology, Surat, India,
(tushardesaisvnit@gmail.com)
pistons would expand so much they could not move in
the cylinders.
1. The cooling system of a water-cooled engine
consists of: the engine's water jacket, a thermostat, a
water pump, a radiator and radiator cap, a cooling fan
(electric or belt-driven), hoses, the heater core, and
usually an expansion (overflow) tank.
2. Fuel burning engines produce enormous amounts of
heat; temp. can reach up to 4,000 °F when the air-fuel
mixture burns. However, normal operating temperature
is about 2,000 °F. The cooling system removes about
one-third of the heat produced in the combustion
chamber. The exhaust system takes away much of the
heat, but parts of the engine, such as the cylinder walls,
pistons, and cylinder head, absorb large amounts of the
heat. If a part of the engine gets too hot, the oil film
fails to protect it.
2. Working of cooling system
The coolant follows a path that takes it from the water
pump, through passages inside the engine block where
it collects the heat produced by the cylinders. Then
flows from bottom to top of the cylinder head (or heads
in a V type engine) where it collects heat from the
combustion chambers. It then flows out past the
thermostat (if the thermostat is opened to allow the
fluid to pass), through the upper radiator hose and into
the radiator. The coolant flows through the thin
flattened tubes that make up the core of the
radiator and is cooled by the air flow through the
radiator. From there, it flows out of the radiator,
through the lower radiator hose and back to the
water pump. By this time, the coolant is cooled
off and ready to collect more heat from the engine.
Exhaust manifold
Engine Head
Engine
Block
Oil
Cooler
Jacket Water
Pump
Thermostat
Radiator

2. Figure. 1 Block diagram of cooling
system
Table 1. Engine parameter by company
peed 1800 Tripping Parameter Set Value
137 mm (5.4 in.) Compressor suction pressure 0.5 bar
152 mm (6.0 in.) Compressor discharge pressure 19.5 bar
ment 27.0 L (1649 cu. in.) Oil filter differential pressure 20 PSI
der 1-8-4-3-6-5-7-2 Compressor oil header pressure 1.20 bar
n Turbocharged-After
cooled
Compressor discharge temp. 85⁰c
eight 2143 kg (4720 lb) Oil separator1 level 25%
ion ratio 8.5:1 Oil separator2 level 5%
ystem Digital Ignition Oil pump discharge temperature 80⁰c
type Woodward 2301A Engine oil level 25%
ater (°F) 210 Engine oil pressure 10 PSI
ler (°F) 130 Engine oil temp. 106.1⁰c
Pressure 1.5 psig Jacket water pump inlet 86⁰c
e Lash 0.38 mm Turbo water level 2.50%
Valve Lash 1.02 mm Turbo water temp 150⁰c
Oil separator sump temp. 80⁰c
Engine speed 1836
As shown in table 1, during our summer training
we found problem in ‘Jacket Water Cooling
System’. Normally engine trips if temperature of
jacket water exceeds then 86 ⁰c or its level reduce
up to 2.50%.But in hot day’s engine trips due to
warning with problem in jacket water. But when
we checked manually jacket water temperature
and jacket water level both were in their normal
value.
3 PROBLEM
From literature review and during our training
period we observed some of the causes which are
responsible for faulty cooling system. Following
are the list of causes.
1] High Ambient temp / high inlet air temp 2]
Low coolant level
3] Faulty water sensor 4]
Faulty water temp regulator
5] Excessive load 6]
Incorrect ignition timing
7] Insufficient flow of coolant through the engine
Among all 7 causes company refused cause no.
2,3,4,6, and 7.Reason of refusing it is as follows:
Table 2. Problem causes and action taken
by
company
Low coolant level They fill coolant according to thei
the time of failure they observe suff
Faulty water sensor
They have cross verified the J/W
elements at different location, In ac
Faulty water temp. regulator
They have bypassed the thermostat
up to 100℃ and also they replace
problem occurs.
Excessive load
In the company engine runs all the
of load recommended by the manuf
Incorrect ignition timing
There is no any chance of incorr
runs engine as per specification-28°
So in this project we worked on the cause ‘High
Ambient temp / high inlet air temp’ which may
be responsible for the failure of cooling system.
Solution for this cause is as follows.
4.1 Engine Room Ventilation
This research addresses engine room ventilation
considerations that apply to the successful
installation, operation and maintenance of
Caterpillar engines, generator sets, compressor
units, and other packaged units. The primary
aspects of a properly designed engine room
ventilation system are cooling air and combustion
air. Cooling air refers to the flow of air that
removes radiant heat from the engine, generator,
other driven equipment and other engine room
components. Combustion air describes the air the
engine requires to burn fuel.
4.2 Sizing Considerations
4.2 (I) Cooling Air
A portion of fuel consumed by an engine is lost to
the environment in the form of heat radiated to the
surrounding air. In addition, heat from generator
inefficiencies and exhaust piping can easily equal

3. engine-radiated heat. Any resulting elevated
temperatures in the engine room may adversely
affect maintenance, personnel, switchgear, and
engine or generator set performance.
Engine room ventilation air (cooling air)
has two basic purposes.
• To provide an environment that permits the
machinery and equipment to function properly
with dependable service life.
• To provide an environment in which personnel
can work comfortably and effectively.
4.2 (II) Combustion Air
In many installations, combustion air is drawn
from outside the engine room via ductwork that is
designed to move a large amount of air with very
little restriction. These installations have very little
impact on engine room ventilation design. Other
installations, however, require that combustion air
be drawn directly from the engine room. In these
installations, combustion air requirements become
a significant ventilation system design parameter.
4.2 (III) Ventilation Airflow
Calculation required for ventilation airflow
Engine room ventilation air required for
Caterpillar engines and packages can be estimated
by the following formula.
V =[
𝐻
𝐷×𝐶𝑝×∆𝑇
+ 𝐶𝑢𝑚𝑏𝑢𝑠𝑡𝑖𝑜𝑛 𝐴𝑖𝑟] × F
Where:
F = Routing factor based on the ventilation type
discussed in the Routing Considerations section of
this guide.
4.2 (IV) Engine Room Temperatures
The primary reason for maintaining engine room
temperature at an appropriate level is to protect
various components from excessive temperatures.
Items that require cool air are:
• Electrical and electronic components.
• Cool air to the air cleaner inlet.
• Cool air to the torsional vibration damper.
• Habitable temperatures for the engine
operator or service personnel.
• Cooling air for the generator or other
driven equipment.
A properly designed engine room ventilation
system will maintain engine room air temperatures
within 8.5 to 12.5°C (15 to 22.5°F) above the
ambient air temperature. For example, if the
engine room temperature is 24°C (75°F) without
the engine running, the ventilation system should
maintain the room temperature between 32.5°C
(90°F) and 36.5°C (97.5°F) while the engine is in
operation.
Maximum engine room temperature should not
exceed 49°C (120°F). If the engine room
temperature cannot be maintained below 49°C
(120°F), outside air should be ducted directly to
the engine air cleaners.
4.2 (V) Atmospheric Heat Rejection Correction
Factor
There are two distinct correction factors, one is
used with wet exhaust and turbo manifolds, the
other is used with dry exhaust and turbo
manifolds. The skin temperature utilized in the dry
manifold calculation is 200°C, approx value of the
wrapped or insulated manifold.
Wet exhaust and turbo manifold correction
factor.
WCF = -.0156 * T
ER
+ 1.4505
Dry exhaust and turbo manifold correction
factor.
DCF = -.011* T
ER
+1.3187
To obtain the corrected atmospheric heat rejection
value, multiply the TMI value by the WCF or
DCF.
4.3 (I) Fan Locations
Fans are most effective when they withdraw
ventilation air from the engine room and exhaust
the hot air to the atmosphere. However, ideal
engine room ventilation systems will utilize both
supply and exhaust fans. This will allow the
system designer the maximum amount of control
over ventilation air distribution.
The fan motors should be mounted outside the
direct flow of hot ventilating air for longest motor
life. The design of centrifugal fans (squirrel cage
blowers) is ideal in this regard, but their size,
relative to the vane-axial or tube-axial fans,
sometimes puts them at a disadvantage [14].
4.3 (III) Fan Sizing

4. Fan sizing involves much more than just selecting
a fan that will deliver the airflow volume needed
to meet the cooling air and combustion air
requirements. It requires a basic understanding of
fan performance characteristics and ventilation
system design parameters.
Similar to a centrifugal pump, a fan operates along
a specific fan curve that relates a fan’s volume
flow rate (m
3
/min or cfm) to pressure rise (mm
H
2
O or in. H
2
O) at a constant fan speed.
Therefore, fan selection not only requires that the
volume flow rate be known, but also that the
ventilation distribution system be known in order
to estimate the system pressure rise. This
information allows the optimum fan to be selected
from a set of manufacturers’ fan curves or tables.
4.3 (IV) Exhaust Fans
Ventilation air exhaust systems should be designed
to maintain a slight positive or negative pressure in
the engine room, depending on the specific
application.
Positive pressure should normally not exceed
0.050 kPa or (0.2 in. H
2
O). This positive pressure
provides the following advantages.
 It prevents the ingress of dust and dirt, which is
especially beneficial for those applications
involving engines that draw their combustion air
from the engine room.
 It creates an out draft to expel heat and odour from
the engine room.
4.4 Routing Considerations
4.4 (I) General Routing Principles
 Fresh air inlets should be located as far from the
sources of heat as practical and as low as possible.
 Ventilation air should be exhausted from the
engine room at the highest point possible,
preferably directly over the engine.
 Ventilation air inlets and outlets should be
positioned to prevent exhaust air from being
drawn into the ventilation inlets (recirculation).
 Ventilation air inlets and outlets should be
positioned to prevent pockets of stagnant or re-
circulating air, especially in the vicinity of the
generator air inlet.
4.4 (II) Single & Dual Engine Applications
These applications will generally require smaller
engine rooms, which are especially challenging in
regard to the use of good routing practices
Ventilation Type 1 (Preferred Design)
Outside air is brought into the engine room
through a system of ducts. These ducts should be
routed between engines, at floor level, and
discharge air near the bottom of the engine and
generator as shown in Figure 2. Ventilation air
exhaust fans should be mounted or ducted at the
highest point in the engine room. They should be
directly over heat sources.
This system provides the best ventilation with the
least amount of air required. In addition, the
upward flow of air around the engine serves as a
shield which minimizes the amount of heat
released into the engine room. Air temperature in
the exhaust air duct will be higher than engine
room air temperature.
Figure 2. Ventilation type 1
5 CONCLUSION
As explained in ‘solution of problem’, during our
industrial training and our project work we found
some of causes which may be responsible for
faulty cooling system. During our project time we
suggest causes of problem like faulty water level
sensor, faulty thermostat, incorrect ignition timing,
and excessive load to the company. Above causes
of problem are refused by them because they
already replaced the elements by new one though
problem is still arise. So now there is only two
causes which are responsible for the problem like
High Ambient temp / high inlet air temp and
Insufficient flow of coolant through the engine.
We can’t find any solution for ‘Insufficient flow of
coolant through the engine’ but we have a solution
which may be help to solve the problem, which is

5. ‘Providing Better Engine Room Cooling Air
Ventilation System’.
We obtain design of the preferred, skid, alternative
and less effective ventilation system from
caterpillar ventilation manual. At the problem
place none of the above listed ventilation system is
establish. So, if they accept one of the ventilation
system there is chance of overcoming the problem.
REFERENCE
(1) Influence of ambient condition on
performance of gas engine, Position-Paper
By The Cimac Working Group ”Gas
Engines”, March 2009.
(2) Fluid level & temp. Monitoring and alarm
system by Raymond A. proulx, Barrington
N.H, United States Patent, patent no-
5,708,412. Date of patent: Jan.13, 1998.
(3) Sensor assembly for a radiator mounted
coolant level monitoring system by Boris
Puscasu, Dearborn Heights, Mich. United
States Patent, patent no-4,638,291, Date of
Patent Jan.20, 1987.
(4) Project Paper High Efficiency Radiator
Design for Advanced Coolant Brandon Fell
& Scott Janowiak, Fall 2007
(5) http://www.coolingtower-
design.com/2011/05/05/radiator-cooling-
system-04
(6) Niko Tripping parameter sheet
(7) http://www.worktrucksales.com/infocooling.
htm