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speedometer reading too high
If the speedometer is too high, this situation is generally caused by poor operation of the odometer sensor.
(1) Vehicle stall test
Stall test is a method to detect the fault of automatic transmission. Specifically, pull the handbrake, step on the brake, change the gearbox to the & quod & quot; position, and then slowly step on the accelerator to observe the engine speed. When the accelerator is fully depressed, the engine speed will not exceed 2600 RPM in most cases. If the display speed is too high, it indicates that the internal of the transmission is seriously worn, and the transmission needs to be overhauled.
(2) Torque converter lockup clutch test
If the fuel consumption of the automatic transmission suddenly increases, the engine speed is very high and the vehicle speed is not high during driving, there is no doubt about the stall test. At this time, it is necessary to suspect the torque converter lock up clutch fault. If it is not locked, the engine and gearbox are not rigidly connected when the car is running, and the speed difference between them is very large, so the car will naturally consume a lot of fuel.
(3) Clutch wear detection for manual transmission vehicles
For models with manual transmission, it is possible to check whether the clutch slips according to the relationship between the engine speed and the vehicle speed. For example, when the engine speed of a car is 2000 rpm, the speed is 60 km / h. If the speed is only 50 km / h, it means that the clutch is slipping and needs to be repaired.As drivers, we need to use the car reasonably according to the characteristics of the engine. Matching engine speed with vehicle speed is one of the driving skills we should master. Therefore, when driving, we often observe the tachometer, so that we can better control the car and find the faults of the car earlier.At present, most cars are basically adjusted to shift up and down at 2000 rpm, and when the speed is lower than 1200 rpm, it needs to downshift. The speed correspondence is almost the same: the second speed of 2000 rpm can be increased to the third speed, the third speed of 42 can be increased to the fourth speed, and the fourth speed of 60 can be increased to the fifth speed. At present, some manual gear models are also very intelligent, which can prompt shifting according to engine speed, vehicle speed and other signals, which is really good news for beginners.
Judge the fault of the vehicle according to the engine speed. The rotational speed reflects the working state of the engine. If the speed is unstable, high and low, it must be an engine fault. There is also a mismatch between engine speed and vehicle speed. Most of the small partners are unaware of this situation, but maintenance workers often use it when detecting faults.
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