Browse

Property For Sale Property For Rent

Used Cars Others

Antiques Collectibles Apparel Baby Kids Items Books， Movies And Music Electronics Free Stuff Garden Outdoor Health Beauty Home Goods Home Improvement Supplies Musical Instruments Office Supplies Others Pet Supplies Sporting Goods Ticket Toys Games Transportation

Business Crafts Design And Web Events Home Improvement Legal Lessons Personal Pets Photography Repair And Technical Support Wellness Writing， Translation， And Transcription Others

Activities & Groups Artists & Musicians Classes & Lessons Events Friendship & Networking Lost & Found Rideshare Sports Teams Volunteers Travel & Travel Partners Skills & Language Swap Other

Why is there oil in the motorcycle air filter?

3 Answers

Miranda

07/23/25 6:18pm

If the motorcycle air filter is a sponge foam filter element, it is normal to have a small amount of engine oil on it. Here is some relevant information about motorcycle air filters: 1. The significance of the air filter: Air passes through the filter and enters the cylinder through the intake valve (throttle), enabling the gasoline to burn. The intake valve opens and closes in synchronization with the piston movement. Therefore, the oil in the filter is the engine oil ejected through the intake valve during piston movement. 2. Excessive oil is abnormal: If there is too much oil, it may be because the motorcycle has been tipped over, causing the engine oil to flow back into the air filter through the breather tube. Additionally, check if there is too much oil in the engine, if the cylinder gasket is damaged, or if pressure is blowing oil from the engine breather tube into the air filter. For scooters, some cylinder head covers may have issues that can also cause similar situations.

Was this review help?

16

5

Share

StOlive

08/10/25 1:55pm

I've been riding motorcycles for ten years, and it's quite common for the air filter to get oily, mainly due to oil vapor backflow. When the engine is running, the high pressure in the crankcase causes oil mist to travel through the ventilation tube and accumulate in the air filter. It could also be caused by overfilling the oil or aging seals failing. If you notice this, clean the oil stains from the air filter promptly; otherwise, dust sticking to it can clog the intake, leading to reduced engine RPM, increased fuel consumption, and even cylinder scoring if left unchecked for long. I encountered this issue after my last long-distance trip, and a simple fix restored normal operation. I recommend regularly checking that the oil level doesn’t exceed the maximum mark and maintaining the vehicle’s ventilation system to prevent abnormal pressure buildup.

Was this review help?

2

1

Share

Expand All

MartinLee

09/22/25 8:38am

I just learned to ride a motorcycle and panicked when I found oil stains on the air filter, so I went to consult an experienced mechanic. He said this is usually normal—during engine operation, a small amount of oil evaporates and enters the air filter with the airflow, but as long as there isn't too much oil, there's no need to worry. However, if there's excessive oil, it indicates a problem, such as overfilling the oil causing spillage or worn piston rings leading to oil leakage. You should check the dipstick to ensure the oil level is within the standard range and clean any dirt on the air filter surface. A greasy air filter reduces filtration efficiency, allowing impurities to enter the engine and potentially damage components, increasing repair costs. So don't underestimate it—routine maintenance can save a lot of trouble.

Was this review help?

20

4

Share

Expand All

More Forum Discussions

Does Leaving the Window Open in Rain Count as a Flooded Car?

Whether leaving the window open in rain counts as a flooded car depends on the specific situation: Counts as a flooded car: If the window is left open during rain, allowing a large amount of rainwater to enter the vehicle interior, causing water accumulation on the floor and resulting in the car being flooded. Does not count as a flooded car: If very little rainwater enters the vehicle interior and can be completely wiped dry, there will be no impact on usage. Signs of a flooded car include: Mold formation: The inner side of car door panels, air conditioning ducts, crankcases, and exhaust holes in the differential area may develop mold and rust. Seats and ceiling fabric in the car may retain hard-to-clean stains and also develop mold. Fluid deterioration: The lubricating grease in four-wheel bearings and half-shafts may degrade due to soaking.

What is the lifespan of an air suspension?

Air suspension has a lifespan of five years. The following introduces the advantages and disadvantages of air suspension: Advantages of air suspension: A major advantage of air suspension is its ability to automatically adjust the stiffness of the springs. When driving at high speeds, the suspension automatically becomes firmer to provide better support for the vehicle, ensuring more stable driving. During prolonged low-speed driving, the suspension automatically softens to offer better comfort for passengers. In SUVs or pickup trucks equipped with air suspension, drivers can increase the stiffness of the suspension to tow heavier loads. Of course, in SUVs or pickup trucks with traditional steel springs, the vehicle body will also lower under the weight of the cargo, and compressing the shock-absorbing springs will increase the stiffness of the vehicle's suspension. Disadvantages of air suspension: As technology continues to advance, the cost of air suspension is decreasing, but compared to conventional spring suspensions, it remains relatively high, making it difficult to popularize in mid- to low-end vehicles. Moreover, the more sophisticated a system is, the more prone it is to damage. Since this system requires the use of airbags or air struts, short-term use does not significantly affect the airbags or struts. However, over time, moisture in the air can adhere to the rubber layer and cause it to crack, leading to the failure of the entire air suspension system. Additionally, small stones kicked up while driving can puncture the airbags, which may also cause the entire system to fail.

How Long Does It Take to Check Red Light Running in Nanjing?

Red light running violations can usually be checked within 10 days. The criteria for determining a red light running violation involve three photos taken by electronic monitoring: the front wheels crossing the stop line, the rear wheels crossing the stop line, and the front wheels crossing the opposite stop line. Only when all three photos are available will it be confirmed as a red light running violation. Penalty points for red light running: According to Article 2, Section 1, Clause 2 of the "Scoring Standards for Road Traffic Violations," driving a motor vehicle in violation of traffic signal lights will result in a 6-point deduction. Article 3, Section 1, Clause 8 states that driving a motor vehicle in violation of prohibitory signs or markings will result in a 3-point deduction. Red light running violations can be checked via the "Traffic Management 12123" app. After opening the app, log in with your ID card, find and click the "Violation Handling" option. Under this section, you can view the current status of your vehicle. If there are any violations, the specific details will be displayed. You can also check violations at the service halls of traffic police branches or offices in various districts and counties by using the touch query terminals.

Can I Retake the Subject 2 Test Immediately After Failing?

If you fail the Subject 2 test, you cannot retake it immediately. You must wait at least 10 days before you can reschedule the test. According to Article 37 of the "Regulations on the Application and Use of Motor Vehicle Driver's Licenses," each subject test can be taken once, and those who fail can retake it once. Those who do not participate in the retest or fail the retest will have their current test terminated, and they must reschedule the test. However, for Subject 2 and Subject 3 tests, rescheduling must be done at least 10 days later. For those who fail the Subject 3 safety and civilized driving knowledge test, the previously passed road driving skills test scores remain valid. During the validity period of the driving skills test permit, the number of rescheduled tests for Subject 2 and Subject 3 road driving skills tests must not exceed five times. If the fifth rescheduled test is still failed, the scores of other previously passed subjects will be invalidated. Subject 2 Test Tips: Seatbelt—fasten it as soon as you get in the car. Make sure not to buckle it incorrectly or to the passenger seat, as the system will directly deem the test failed. Do not unfasten the seatbelt at any time during the test. After getting in the car, adjust the seat and mirrors, fasten the seatbelt, turn on the left turn signal, shift to first gear, and release the handbrake. These six steps are essential. Ensure all preparations are complete before starting. There is no time limit for reversing into the parking space, but note that stopping during the process is not allowed. If the wheels remain stationary for 3 seconds, the system will judge it as stopping midway. Therefore, controlling the speed is crucial.

How Many Hours Are Required for Subject 2?

According to the 'Motor Vehicle Driver Training and Examination Syllabus,' for the commonly tested C1 and C2 driver's licenses, a minimum of 16 hours is required for Subject 2. Below is a detailed introduction to the Subject 2 examination: Overview: Subject 2, also known as the small road test, is part of the motor vehicle driver's license assessment and is the abbreviation for the field driving skills test. The C1/C2 test items include five mandatory components: reversing into a parking space, parallel parking, stopping and starting on a slope, turning at a right angle, and driving through curves. Additional Information: If the first attempt at Subject 2 is unsuccessful, a retake is allowed. If the retake is not taken or is still unsuccessful, the examination is terminated, and the applicant must reschedule the test after ten days. Within the validity period of the driving skills test permit, the number of times Subject 2 and Subject 3 road driving skills tests can be scheduled for examination must not exceed five.

What are the symptoms of a damaged oil check valve?

Symptoms of a damaged oil check valve include extremely unstable idling, even stalling, flashing warning lights, failure to meet emission standards during annual inspections, oil burning, and blue exhaust smoke. A damaged oil check valve cannot be repaired and must be replaced. Classification of oil check valves: Check valves come in two types: straight-through and right-angle. Straight-through check valves are installed on pipelines via threaded connections. Right-angle check valves come in three forms: threaded connection, plate connection, and flange connection. Hydraulic check valves, also known as locking valves or pressure-holding valves, function similarly to check valves by preventing reverse oil flow. However, in hydraulic circuits requiring reverse oil flow, control oil pressure can be used to open the check valve, allowing oil to flow in both directions. Working principle of oil check valves: Compressed air enters through port P, overcoming spring force and friction to open the check valve, allowing compressed air to flow from P to A. When there is no compressed air at port P, the valve remains closed due to spring force and residual air pressure at port A (chamber), preventing airflow from A to P. Check valves are used in applications where reverse airflow is not allowed, such as between an air compressor and an air tank. When the air compressor stops working, the check valve prevents compressed air in the tank from flowing back into the compressor. Check valves are also often combined with throttle valves, sequence valves, etc., to form one-way throttle valves or one-way sequence valves.

Trending Ranking

What are the hazard warning lights on a car?

How to Determine if a 12V Battery is Fully Charged?

How to Open the Car Trunk from Inside?

What are the length and width of the Boyue's body?

Is SWM a Domestic or Joint Venture Car Brand?

Can plug-in hybrid vehicles get green license plates?

Can Summer Tires Be Used in Winter?

How to Turn Off the Side Slip System in Toyota Camry?

What does the TC slash on the car dashboard mean?

Must the ETC owner be the vehicle owner?

More Forum Discussions

Is there a big difference between BMW X3 and X5?

What is the AFL light?

How long does it take for chassis armor to be road-ready?

What does plug-in hybrid mean for cars?

Help

Cookie

Cookie Settings

© 2025 Servanan International Pte. Ltd.