GT535 HighSpeed Shaking Reason Revealed: A Failure Triggered by Poor Quality Gasoline

September 11, 2025
by 杨纯

Car shaking is a common but complicated failure phenomenon in automobile driving. Recently, we received a report of a GT535 car, the car speed reached 110km/h, the engine speed 1800rpm when the body shook obviously. Through exhaustive diagnosis and testing, an unexpected cause was finally found: poor quality gasoline. The following is the whole process of diagnosis and solution of the fault.

Fault Description

During the test drive, it was found that the GT535 had a significant auto shake at 110km/h and 1800rpm engine speed. As the speed and rpm change, the shaking is sometimes strong and sometimes weak, but always concentrated in a specific speed and rpm range.

Diagnostic process

1. Tire and chassis inspection

◦ Initial suspicion of modified 19-inch rims, dynamic balancing, or radial force fluctuation issues.

◦ Rebalance all four wheels and check chassis suspension.

◦ Replace the original tires, the body shaking phenomenon did not improve.

2. Test Drive Summary

The shaking phenomenon is confirmed by several test drives:

◦ Stable cruise: 110km/h, engine speed 1800rpm when the shaking is the most intense.

◦ Throttle status: jitter disappears when the throttle is released or the engine speed is high.

◦ Manual mode: shaking is obvious at 1800rpm, no shaking at high speed.

Conclusion: The shaking is concentrated in the engine in the range of 1600~1800 rpm, which may be related to the abnormal vibration of the powertrain.

3. Preliminary check of the engine system

◦ Mixed gas preparation: fuel pressure is normal, intake piping is well sealed, clean the throttle, and delete the mixture tuning value.

◦ Ignition system: check spark plugs and ignition coils in good condition.

◦ Software upgrade: after updating the DME programming, the shuddering improved slightly, but not completely resolved.

4. In-depth analysis: another suspect

Inspection of the gasoline revealed a dark color and pungent odor, exhibiting typical characteristics of poor-quality gasoline.

Solution

Replace high-quality gasoline, delete the mixture tuning value, and retest the car.
Troubleshooting completely, vehicle speed 110km/h, engine speed 1800rpm, no longer shakes.

Case Analysis and Revelation

The root cause of the GT535's car shaking while driving is poor-quality gasoline. It causes the engine power to drop under certain loads and speed ranges, similar to the phenomenon of “high-grade, low-drag”, which triggers abnormal vibration in the powertrain.

Key takeaways:

1. The dangers of poor quality gasoline: not only does it affect power output, but it also tends to cause complex malfunctions.

2. The importance of diagnostic ideas: do not limit yourself to superficial symptoms, such as tires or driveshaft problems, but start with a comprehensive analysis of the powertrain.

3. The impact of gasoline quality on engine performance: Poor-quality fuel is a potential threat to automotive failures, and should attract the attention of more car owners and maintenance personnel.

Summary

This case fully illustrates the importance of meticulous diagnosis and the profound effect of fuel quality on vehicle performance. Poor-quality gasoline causes the engine output to drop in a specific load and speed range, resulting in stalling and thus body vibration. Vehicle owners are advised to choose regular gas stations to avoid unnecessary losses caused by poor-quality gasoline. This failure phenomenon can easily lead to misjudgment and cause one to think that the shaking is caused by factors such as tires or drive shafts. We hope this case will provide valuable reference for other vehicle owners and maintenance technicians.