Wrangler 2012–2017 models, high-strength off-road, high engine temperature, high temperature gearbox, poor air conditioning refrigeration, troubled car owners for many years, although many solutions have been proposed to solve part of the problem, so far there is no complete solution. The Taihangshui team is mainly a horse wrangler for play, and after being deeply affected by it, they worked hard on research and development. After two years of continuous improvement and testing, they finally obtained a complete set of solutions, which are now being introduced to the majority of riders.
Principal Investigator: Jiang Shemin, Haisheng, Taihangshui For consultation, contact Mr. Qingqing, WeChat zhaiminqiao960605
Chapter 1, Research on the High Temperature Mechanism of Wrangler
Section 1, Model 1 with 3.6 displacement, engine heat dissipation analysis, program control of main fan, 3.6 displacement, 209 kW, undoubtedly a high-efficiency engine, after testing, normal driving, engine water temperature 110 degrees, main fan start temperature 108 degrees, As the temperature increases, the fan speed increases proportionally. When it reaches 119 degrees, the engine output power is limited. When it reaches 125 degrees, the engine water temperature alarms, and the output is limited to idle speed. The fan load reaches 90%, and no longer increases. The power of the main fan is about 400 watts, controlled by the main computer, and the motor is controlled by frequency conversion.
The thermostat response is a purely mechanical heat-sensitive expansion oil ejector type, which is slightly opened at 100 degrees, opened about 40% at 109 degrees, and fully opened at 125 degrees. Since the expansion oil core is directly immersed in the antifreeze, it takes a few seconds for the heat to penetrate the core, that is, 109 degrees, but it takes about 5 seconds to open to the preset 40%. All mechanical thermostats have this Delay. The water pump is running, and the engine is directly rotating. The higher the speed, the greater the water volume, and the corresponding increase in pressure. Generally speaking, the water volume is sufficient.
Radiator layout: the radiator of the main water tank is a combination of aluminum and bakelite, the heat dissipation area is limited by the space, and the fan is placed behind; the front of the main water tank is the air conditioner radiator, which almost covers the entire main water tank; the transmission oil radiator is arranged on the air conditioner radiator In front, cover half of the area. The cooling air is first blown to the radiator of the gearbox, and then through the radiator of the air conditioner, then blows to the main water tank, and is sucked out by the main fan. Between the three radiators, there are no shrouds and no forced ventilation. The main water tank and the main fan have windshields, which are forced ventilation and cooling.
The hot air radiator of the air conditioner is arranged in a cabin where the air conditioner is discharged, and the hot and cold air is switched by the windshield. Waterway combing: The engine return water is a common inlet. The cooled water flows into the engine. After absorbing the heat of the engine, the high-temperature water is pressurized by the water pump and ejected. Device–main water tank–engine inlet return; air-conditioning hot air channel, inner diameter 16mm, water pump outlet—air-conditioning radiator—engine inlet return; engine oil cooling channel, inner diameter about 13mm, water pump outlet– -Oil cooling base—engine water inlet back.
2. Causes of engine high temperature
A, The thermostat is opened too late and too slowly, resulting in untimely water supply. When the engine is at full throttle, it emits a lot of heat, and the water temperature is 110 to 120 degrees. It will not exceed 10 seconds, and the engine will immediately limit the output power. And 110 degrees is the normal water temperature of the engine, and the room for temperature rise is too small.
B. The power of the main fan is insufficient, the turn-on time is too late, and the response speed is also lagging. When the thermostat is fully opened, the air volume reaches the maximum value, but it is not enough to cool down the hot water at about 120 degrees, that is, the heat dissipation is insufficient, causing the water temperature to continue to rise, exceeding 125 degrees in an instant, the computer high temperature alarm, and the engine returns idle.
C. The heat dissipation of the main water tank is unreasonable. The transmission radiator and the air conditioner radiator are blocked in front. When the wind reaches the main water tank, it has already been preheated, and the heat dissipation ability is greatly reduced.
D. The radiator of the air conditioner is defective. Although no warm air is used in hot weather, the radiator of the air conditioner is always circulating high-temperature water. This part of water is equivalent to 1/4 of the main water tank, and it returns to the engine almost without cooling down. The same is true for the engine preheating water circuit, which always returns high-temperature water directly to the engine. E, The radiator is easy to accumulate a large amount of flocculent debris, which blocks the passage of air. On the whole, this engine is a high-efficiency high-temperature engine, pursuing small displacement, high power and low fuel consumption. The engine itself is very good, but the cooling capacity of the vehicle is insufficient.
3. Analysis of gearbox heat dissipation. The gearbox works under high load and generates a lot of heat, which is far from enough to rely on natural ventilation. After Model 12, a gearbox oil radiator is added and arranged at the front of the engine compartment. It seems to be solved, but it is far from it. . Because the main fan is very slack, it hardly starts during normal driving. When the vehicle is driving at low speed and with high resistance, the oil temperature rises rapidly, and the gearbox is frequently protected, limiting the power output.
4. The reason for the high temperature of the gearbox: insufficient ventilation of the gearbox oil radiator.
Section 2, 3.0 Displacement Model The structure of this car is almost the same as that of 3.6, except that the cylinder displacement is reduced to 3.0, still has six cylinders, the power and torque are also reduced by one level, and the same heat dissipation system is used. Due to the reduced engine power, the heat emitted is naturally less than that of the 3.6 model. On the surface, it seems that the high temperature phenomenon is lighter, but it is not the case. The reason for its high temperature is exactly the same as 3.6.
In the third section, the 2.8-displacement model is a diesel supercharged engine with a power of 147Kw and a torque of 460 Nm, a high-efficiency high-temperature diesel engine. The heat of a diesel engine is lower than that of a gasoline engine, and the overheating of the engine is relatively small. Unfortunately, an intercooler is added in front of the air conditioner refrigeration evaporator, which aggravates the tendency of high temperature and affects the effect of air conditioner refrigeration. Its heat dissipation layout is roughly the same as that of a gasoline engine, and the heat dissipation structure of a gearbox is exactly the same. Under the cover of an intercooler, the heat dissipation effect of a diesel vehicle gearbox is even worse.
Chapter Two, Wrangler High Temperature Control Program Research
Section 1, Models with 3.6 and 3.0 Displacement No modification of any single item can solve the problem, it is a systemic defect that must be dealt with in an all-round way.
1. The main fan control of the engine heat dissipation. The program control of the modified main fan is controlled by the main computer. We cannot modify it. Although there are companies in the market that sell the modified program, the price is about 5,000 yuan, and the original car program needs to be changed, worrying about affecting the stability. , we drop this idea. Plugging in a computer to form a second control circuit is our research and development direction. During daily driving, use the original car computer to control; when driving in the desert, disconnect the original car computer control circuit, connect the external computer, and control the opening time and ventilation volume of the fan according to the water temperature according to our preset program. The two control modes are switched by one key.
2. The water supply method of the thermostat is modified between the thermostat and the engine, and a three-way flange is added to output a second water channel with an inner diameter of 20 mm. After a valve control, the water is directly sent to the main water tank, which increases 39 % of the water delivery volume, when the thermostat cannot be fully opened, the parallel second waterway plays the function of sending a large amount of water. Close the valve during daily driving to achieve water supply in the original car mode; open the valve when entering the desert to achieve enhanced water supply. The lagging water supply problem of the thermostat is completely eliminated.
3. Modification of radiator air supply At the front of the engine compartment, between the ghost face and the radiator, two fans are added as supplements to the main fan. When driving normally, this additional electronic fan does not work; when entering the desert, it can be turned on with one button. Add 50% of the air volume of the original car. This modification completely solves the high temperature of the gearbox.
4. Modification of the air conditioner heating radiator Add a valve to the water pipe of the air conditioner radiator. When warm air is needed, the valve opens to realize the original car mode; when entering the desert, close the valve so that this part of the water is cooled by the main water tank, and The radiator of the air conditioner warm air also becomes normal temperature, and the cooling effect of the air conditioner is greatly enhanced.
5. Clean up the sundries in the radiator in time to ensure the heat dissipation area and keep the ventilation smooth.
6. For extreme racing vehicles, especially in the low-speed four-wheel drive full throttle state, it is necessary to further improve the heat dissipation capacity of the engine, and it is necessary to add additional water tanks and waterway control.
In the second section, the diesel 2.8 model occupies the position of the additional electronic fan due to the addition of an intercooler radiator, and the main function of the electronic fan is to dissipate heat from the gearbox. The gearbox oil of the diesel model needs to be strengthened by adding a radiator. The electronic fan in front of the engine compartment only contributes 3 degrees of cooling to the engine, which is negligible. At the position of the front bumper winch, the original car has a large space, where a long radiator can be added, with a windshield and two small fans, 2X80 watts is enough. Connecting transmission oil in series to this strip radiator can increase the heat dissipation of the original car by about 50%. The modification of the main fan control, the modification of the second water circuit of the thermostat, and the modification of the cooling water circuit of the air conditioner are the same as the modification of the gasoline model. Keeping the radiator clean is an essential part of vehicle maintenance.
Chapter 3, Wrangler High Temperature Control Program Implementation
The first section, 3.6 and 3.0 displacement models
1. Modification of engine heat dissipation main fan control Modification of automobile circuit is a very rigorous technical work. The circuit layout, the purchase of external computers, the programming and setting of the program, the matching with the original car, and the switch logic setting are all repeated adjustments and tests. Disconnect the original car computer and turn on the plug-in computer at the same time, but the fault code of the original car computer cannot be triggered, and during the switching process, it cannot cause electrical shock to the two computers. Stability testing was carried out for 10 months. External computer logic, through the water temperature sensor to obtain the water temperature signal, corresponding to the new fan speed, the water temperature is about 10 degrees lower than the original car, and the normal driving water temperature is 100 degrees, compared with the engine high temperature protection of 120 degrees, 20 degrees is reserved Warming up space.
2. Modification of the second waterway of the thermostat Specially designed and manufactured a thermostat tee flange, disassembled the thermostat, added this tee flange between the engine and the thermostat, and fixed it with extended bolts. The three-way flange outputs a pipe joint with an outer diameter of 24 and an inner diameter of 20, which is connected to a manual valve. After the valve is a heat-resistant rubber hose with an inner diameter of 24, which is connected to the water inlet of the main water tank through a tee. The tee flange is also equipped with a temperature sensor, and the signal line is connected to the external computer.
3. Radiator air supply modification At the front of the engine compartment, behind the ghost face, there is a space about 10 cm thick, where two 10-inch electronic fans are installed, each fan is 100 watts, and the air supply volume is 50% of the original car. This fan blows directly on the gearbox radiator, which completely improves the gearbox oil temperature, but makes little contribution to the cooling of the engine and can be ignored.
4. Modification of the air conditioner heater radiator The outlet pipe of the heater radiator is located above the back of the engine compartment, just enough space to install the vacuum valve, and the negative pressure inside the throttle is used to control it.
5. For competitive vehicles with extremely high requirements, water is provided in parallel to the air-conditioning waterway, and the additional radiator is guided separately, and the water is sent back to the engine water inlet after cooling down.
6. Circuit and switch integration The external computer circuit, electronic fan circuit, and vacuum valve circuit use multiple sets of relays. We set up a relay box on the left side of the engine compartment, select high-quality electrical appliances and wires, and make fixed connections. The control switch is installed on the crossbeam just above the front windshield glass, and there are 6 switches arranged, which are divided into electronic fan, desert/daily mode switch, A-pillar auxiliary light, vehicle platform, ABS on/off, and a spare switch.
The second section, 2.8 displacement diesel Wrangler
1. The main fan control, thermostat waterway, and air conditioner heating valve modification are exactly the same as those of the gasoline model.
2. To dissipate heat from the gearbox oil, connect a radiator and fan in series, install it in the space behind the front bumper, and make a protective plate.
3. Diesel models do not provide special heat dissipation modification for competition, and its space has been occupied by the additional radiator of the gearbox.
Section 3. Difficult choice of accessories. When determining the plan, making a list, and purchasing parts, I encountered great difficulties. Repeated testing and screening were required. The chaos in the accessories market was a great trouble, and high-priced purchases could not ensure the quality. The main parts can only be designed and manufactured by ourselves. After two years of repetition, the list of qualified parts was determined. The first batch of 8 vehicles has been refitted, and the second mass production kit is in progress. After the above modifications, one-key switching between the original car mode and the desert mode has been realized. The desert mode can meet the needs of high-intensity sand flushing and heat dissipation.
Chapter 4, the hard test road
In the first section, the electronic fan test cooling modification has gone through a long process. At first, it started with the electronic fan. After 6 months of testing, the Ulan Buhe Desert and the Badain Jaran Desert traveled 3,000 kilometers. The high temperature problem of the gearbox, Completely resolved, but engine overheating still occurs.
In the hottest season of July and August, in the Kumtag Desert in Shanshan County, Xinjiang, the electronic fan still eliminated the high temperature of the gearbox, but the engine overheated very seriously, and the air conditioner had almost no cold air. In the highway test, the electronic fan reduces the temperature of the engine by 3 degrees. The quality of the electronic fans on the market is chaotic, and many of them claim to be original parts, but they all fail quickly. In the end, the original factory of Japan Denso was selected to complete the test smoothly. We are sure that the high temperature of the gearbox has been completely solved by this electronic fan. The products of Denso have reliable performance and reach the level of the original car.
Section 2, Thermostat Modification Test For engine cooling, after the electronic fan failed, the inner core of the thermostat was removed first, and I ran in the desert for a year, barely coping with medium-intensity crossing. In the Badain Jaran Desert in summer, when climbing the big pot slope, there are still high temperatures from time to time, and the Kumtag Desert still cannot meet the requirements of summer. We are convinced that the modification of the thermostat can significantly improve the cooling of the engine and ensure the water supply, but the cooling is lacking in high-intensity conditions, and the main fan needs to increase the air supply. The thermostat is a necessary modification item. Fortunately, our partner is an OEM manufacturer of European and American auto parts. It is handed over to the technical department to develop the second waterway design of the thermostat, use aluminum alloy to process the tee flange, and purchase high-temperature and high-pressure rubber hoses and pipe fittings from OEM manufacturers. Second Waterway. Considering that the second waterway only needs to be switched once in winter and summer, and does not need to be switched in normal times, it is confirmed that the manual shut-off valve is used for control to ensure reliability. The second waterway has been tested for one year, covering 5,000 kilometers of desert, and the operation is reliable.
In the third section, the design of the main fan control modification test plug-in computer has gone through a long and painful process. Reliability has always troubled us. Car electronic control modification is the most stringent project. It is extremely difficult to reach the original car level, and safety is also important. test. Repeatedly, it takes a year to finalize, and then there is a long-term test. After various extreme tests, the system is stable and reliable. Anti-interference, anti-high temperature, and anti-turbulence are the main difficulties, and solutions have been found one by one. Cured package, strong and stable.
Section 4, air conditioning modification test After installing the vacuum valve, a series of unstable phenomena occurred, and it was stabilized after several times of setting and matching. Section 5, overall commissioning After all the modification and construction are completed, the reliability of the installation needs to be checked one by one. The inspection focuses on leakage, false welding, poor contact, and pipeline fixing. After confirming that there are no defects, the sports car will be tested to check the matching status of the four modifications. After the desired effect is achieved, it will be delivered for use. This is a systematic project, and various modifications affect each other, depend on each other, and borrow from each other. In the 10,000-kilometer desert test, we confirmed that this system has completely solved the three major problems of the Wrangler’s high engine temperature, high temperature gearbox, and cold air conditioner. It is reliable in operation and reasonable in cost.
Q&A:
1. Increase the cooling effect of the water tank on the engine. The water pump of the original car had sufficient water supply, but the thermostat forcibly cut off the water supply. When the thermostat was fully opened, it was too late. The heat dissipation area of the water tank of the original car is sufficient, and the actual test of increasing the water tank has little effect on cooling the engine.
2. The role of the electronic fan in cooling the engine. It is popular in the market to add an electronic fan in front of the engine compartment, increase the air supply, and blow directly on the gearbox radiator, which completely solves the problem of the gearbox. However, most of the blown wind escapes from the gap between the transmission radiator and the air conditioner radiator, and only a small amount of air blows into the air conditioner radiator, and then escapes from the gap between the air conditioner radiator and the water tank. For the most part, the wind that actually passes through the water tank is very little, and it is the wind that has been preheated in two stages, which only has a 3-degree effect on cooling the engine.
3. The main program of the computer is modified, and the start time of the main fan is advanced, which has a certain effect on cooling the engine. However, the thermostat is not fully opened before the water temperature is 108 degrees. Even if the air volume is increased and the water supply is insufficient, it still cannot be effective. cool down. When the temperature is already high, the fan is turned on to the maximum power of 400 watts, and the water volume is also the largest, but it still cannot meet the needs of heat dissipation, and the power of the fan is too small. Moreover, equivalent to 25% of the hot water of the air conditioner in the main waterway and 15% of the hot water in the oil cooling pan, it does not pass through the main water tank and returns directly to the engine.
4. The two channels of hot water for the air conditioner and the oil cooling pan also serve as a buffer for the pressure relief of the low-temperature operation of the water pump. Water pipes may burst. The oil cooling pan also has the function of preheating when starting at low temperature, which cannot be cut off.
5. The main fan is a program-controlled speed-regulating motor, which cannot be controlled manually, at least not when driving, and must be plugged into a computer.
6. Replace the main fan, which is equivalent to changing the main program, and it will have an effect, but it cannot completely meet the needs. And the modification is too complicated.
7. For refitting, the functions of the original car must be retained to the greatest extent. When there is a problem with the modified functional parts, it must be able to switch to the original car mode immediately. The simpler the modification, the higher the reliability.
8. The original design of the Wrangler has insufficient heat dissipation on the whole, and it is a systemic problem. A single modification project cannot solve the problem. The reliability of the modification must reach the level of the original car parts and be able to withstand harsh use. Any change will cause unexpected problems, and only long-term testing can confirm reliability.
