Author / Crab Claw Chaotian
Compiled from: N5#
80824a#a7d#
BMW/BMW
N54 Modification
edda1a0d9588 inline#04a0d9# Turbo engine
As the mainstream engine of BMW, the 3.0L turbo N54 does have a lot of potential for modification, but there are also some common faults that will appear in the modification and the original factory In use. I hope this summary of faults can help you make a plan before modifying or buying a car, so that you can find the right direction when you encounter problems. Some of these principles are also applicable to other engines.
Let me talk about a digression that applies to all models: In order to find oil leakage and other problems in time, and for better heat dissipation, it is strongly recommended to put the plastic cover on the engine The board is removed. After disassembling, you will find how thick the insulation on the back of the cover is.
The importance of heat dissipation and the effect of high temperature on knocking, fuel consumption, and power have been discussed in many previous articles, so I won’t explain it here. You can call up the search link in "dry goods search" under the public number, search for "heat dissipation".
1. High-pressure fuel pump failure (HPFP)
This problem is that BMW has admitted that it does exist. Generally speaking, this failure has little to do with other components. Writing non-original ECU programs and replacing parts such as intake and exhaust will not affect the probability and severity of this problem.
Expression
- Slow start when ignition
- The light
- enters the power protection mode, the power is weakened
588 Common fault code
- P142E: High pressure fuel pump pressure is too low
Low pressure in HPFP system – injection disables to protect catalytic converters.
- 2FBF: Injection pressure problem
Fuel pressure at injection release.
- 2FBE: Pressure problem during shutdown
Fuel pressure after motor stop.
- 2 29DC: Fuel injection off
Cylinder injection switch off.
- 29E2: Fuel rail problem
Fuel injection#
- P0301 (1-6): 1 (1-6) cylinder misfire and lack of cylinder
Cylinder misfire.
2. Turbine failure, the exhaust side bypass valve sounds
The connecting rod of the turbine exhaust side bypass valve may sound due to wear.
The role of the bypass valve is to execute according to the command value of the ECU, and control the turbine pressure , so this kind of wear may cause the bypass valve to open The degree is abnormal, that is, there is a big difference between the actual execution value of the turbo pressure and the command value of the ECU.
Although the ECU will have some correction capabilities under closed-loop conditions, everyone should know that the turbine pressure is abnormal. as a result of. Cylinder explosion, knock, air-fuel ratio, tube burst. It is recommended to change the turbine as soon as you hear the abnormal noise. Changing the turbo is always cheaper than restructuring the engine.
Because this wear is related to turbine pressure and pressure change, the turbine pressure is increased in ECU , Frequent high-load driving, mileage accumulation and other situations will cause this problem to appear early.
For turbines that have already experienced this problem, try to control the load of the turbine (power) before replacing the new turbine. After all, the wear and tear of the turbine oil seal will bring great safety risks.
Cool Music recommends that the oil temperature gauge must be installed or called out to monitor at any time.
Because for all engines, heat engine is a must. According to design requirements, the N54 must allow the overall engine temperature or at least the oil temperature to reach above 70°C before trying to step on some high loads. Civil engines of other brands must be heated to 70°C-80°C before you can step on the accelerator.
Although factors such as the oil type and the installation position of the oil temperature gauge will affect this data, is almost 70°C This is the general lower limit for street cars.
Expression
- Turbine exhaust side noise
- 动力不normal
- The turbine oil seal is worn too much, causing the oil to be mixed into the exhaust gas flow, and there is blue smoke at the exhaust pipe mouth
Fault code: Low boost
Third, the fuel injector is blocked or leaked
Carbon deposits formed after flameout may affect Work to the fuel injector.
Due to the positional relationship between the fuel injector and the spark plug, if leaks oil, the oil is easily contaminated on the spark plug electrode, which will cause difficulty in starting and fire during driving. .
If checking the spark plug, it is found that electrode 05588 is wet , it is very likely that the fuel injector is leaking, can only replace fuel injector . If you find that the electrode does not have wet gasoline after checking the spark plug, it may be that the fuel nozzle of is clogged , you can clean the fuel nozzle under and try loading the car.
If it is confirmed that there is a problem with one of the injectors, it is recommended to replace the 6 injectors together. .
adding a breathable pot may make this kind of carbon accumulation slower. Using some ethanol gasoline will make this kind of carbon accumulation slower. The effective cleaning function of gasoline additives or nozzle cleaning construction will remove some of this carbon deposit.
Expression 0d9b#58805#cf05 Difficulty in cold start
Fourth, the booster pipe leak
Increase the target boost value in the ECU, and the exhaust side When driving a pure original car with a high pressure caused by a failure of the valve, or when driving a pure original car with a high load, the original pressure pipe may also burst, loose, and seal the rubber ring.
Although there is a pressure sensor and a manifold pressure sensor on the pipe not far behind the turbine for data comparison, it is found that the ECU will enter the protection mode to limit the power after the air leak, but this protection design may not be absolutely reliable and effective.
When the actual pressure entering the manifold does not reach the target value of the ECU, and the protection mode does not work effectively, the turbo may always be in a high-load work of hard boosting. The speed, temperature and wear are not well controlled.
At this time, a large proportion of the intake air drawn by the valve may also be without the front end tube. Road, sucked directly from the leak. It has not been filtered by air filter and calculated by AFM.
N54 original factory booster pipeline design margin is not too large, directly replace the original factory pipeline during power conversion is very necessary. If you are driving a car that has leaked air and has not replaced the pipe, you should try to control the engine load and turbo pressure.
In addition to the pipe itself, the pressure relief valve on the inlet side of is also life-saving.
After long-term use, the pressure relief valve may not be tightly sealed, causing the actual detected turbine pressure to be lower than the ECU target pressure. This will cause the load of the turbine to be always higher than , and the temperature and wear rate will be higher . Therefore, when replacing the original factory booster pipe, the original factory pressure relief valve can be replaced with .
From the perspective of Engine Management, External pressure relief valve will lead to re-release In a very short period of time after stepping on the accelerator pedal, the intake air volume measured by the front end AFM is inconsistent with the actual air intake volume in the cylinder. , The internal relief valve should be replaced as much as possible.
From the perspective of turbine condition , we are setting the boost value very high. At that time, externally drained pressure relief valve is more suitable for .
Expression
- There is a sound of air leakage during acceleration
- 2cfb7 There is sludge near the pipeline
- Idle speed is unstable
- Power is not normal
Fault code: low boost, Low manifold pressure, low turbo pressure, abnormal EGR
V. Valve oil seal leak
Valve oil seal Excessive wear or cracking between the valve stem and the valve stem causes the oil above the oil seal to leak into the cylinder below, forming a large amount of carbon deposits.
This situation is mainly caused by insufficient design life or insufficient oil lubrication. Under the condition of high speed and high oil temperature, the wear rate will be larger.
Engine oil with high speed, high oil temperature and insufficient performance will accelerate the wear here. For cars that drive more intensely, it is wise to use high-quality engine oil, control oil temperature, and change engine oil in time for new cars .
After the oil leak occurs, should be checked as soon as possible for the wear of the valve stem, and confirm Whether to replace only the oil seal or replace the oil seal and valve stem at the same time. BMW has some special tools for changing oil seals without removing the cylinder head. You can do it at home by yourself, which is not difficult.
In some BMW groups, you can find riders to borrow this tool from each other.
Expression
- Spark plug, valve ring, wet oil in the cylinder fc4d#7#2cfb7d#fc4d#fc4d# The exhaust port has blue smoke caused by burning engine oil, which is more obvious when the car is cold.
- Low engine oil alarm
No due to this problem For the directly corresponding fault codes, you can only observe the blue smoke of the exhaust gas and frequently check the condition of the spark plug.
Six, serious carbon deposition
In addition to the problem of easy carbon deposition inherent in direct injection engines, the valve oil seal mentioned above Once the problem occurs, the rate of formation of N54 carbon deposits will be very high.
The hazards of carbon deposits to the engine have been explained in detail in many previous articles and Q&A. In short, it is a Not a small problem. For specific explanations, you can call up the search link in "Dry Goods Search" under the public number, search for " carbon deposit", "burning oil", "engine management" .
In order to reduce the rate of carbon deposition, you can install an oil breather, or use it appropriately. Some ethanol gasoline.
In order to deal with severe working conditions after severe carbon deposits, you can add thicker fuel injection in ECU , you can use higher-grade gasoline, or strengthen the engine cooling system.
In order to clean up carbon deposits as much as possible, you can use some really effective cleaning gasoline additives or in-cylinder cleaners , You can also perform a thorough manual cleaning of the valve and piston crown after removing the cylinder headMade.
Expression
- Difficulty in starting 2cfb4d#
There is no fault code directly caused by excessive carbon deposit.
VII. Timing failure
Expression
- The power is not normal when driving at low speed, and the power is not normal at low speed. Instability
- Fuel consumption increase
- Cold start difficulty
- Frequent entry into power protection mode
- Engine failure light
Part of the fault code
- P1520: exhaust side camshaft position sensor failure P1520:#
- P1523: Camshaft position sensor jam on the exhaust side
- P1397: Camshaft position sensor B failure
- 2A82: Variable timing system intake solenoid Valve failure
- 2A87: Variable timing system exhaust solenoid valve failure
Eight, water pump problem
4da0e#Generally, when the mileage of reaches 100,000 to 120,000 Km, the water pump may have a sudden problem .
The coolant circulation is not smooth or completely stopped. Even in the very low load conditions like idling, the damage to an engine can be said to be fatal. The heat dissipation performance of the engine body and the turbine is greatly reduced, and the temperature of the oil rises rapidly and it is easy to reach a level sufficient to overheat the oil and fail.
Once the oil is overheated, it is very common to pull the cylinder, break the connecting rod, and break the piston. Even if there is no obvious excessive mechanical wear, the overheated oil should be replaced immediately.
It is recommended that you replace the pump in advance before any problems occur.
Expression
- If the water temperature is too high, the oil temperature and exhaust temperature will also increase at the same time.
- The power is not normal
- Knock (not one can be heard directly)
- The sound of the water pump and the fan is loud
Common fault code
- 2E84: Replace the water pump and thermostat
- FC377A: due to blockage , The pump is turned off
- Check Fuses F07, F09, 80, 33: Check fuses F07, F09, 80, 33
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04a7a0#
