How to Read the Oil Dipstick?
4 Answers
Reading the oil dipstick involves the following steps: 1. Unscrew the dipstick and wipe it clean with a clean soft cloth or tissue; 2. Reinsert the dipstick and then pull it out again. There are upper and lower limits marked at the end of the dipstick. Observe the part of the dipstick that is wetted by the engine oil; 3. If the oil level is between the upper and lower limits, it means the oil quantity is just right. If the dipstick does not reach the lower limit, it indicates insufficient oil. If the oil level is above the upper limit, it means too much oil has been added. The oil dipstick in a car is a commonly used measuring tool to check the lubricant level in the oil reservoir. Due to the curved path of the dipstick insertion hole, the dipstick must be able to deform when inserted and rebound to its original shape when pulled out.
First, park the car and turn off the engine, then wait for about 10 minutes to allow the oil to drain back into the oil pan. Park the car on level ground, open the hood, and locate the yellow or orange pull ring. Pull it out, wipe it clean with a tissue, then fully reinsert it and pull it out again. This time, carefully observe the end of the dipstick—there are usually two dots or notches as markers—the oil film should cover the area between the upper and lower marks. When the engine is cold, the optimal oil level is at about three-quarters of the upper mark. Too much oil can damage the seals, while too little will lead to insufficient engine lubrication. I usually check it twice a month and also observe the oil color—if it turns black, it’s time for a change. If the dipstick is completely covered in oil and hard to read, it’s likely overfilled. Beginners should avoid checking immediately after turning off the engine, as the oil is still circulating and may lead to incorrect readings.
Before pulling out the dipstick, ensure the car is parked on level ground and turned off for ten minutes. Wiping the dipstick clean is crucial—last time my neighbor checked with a dirty dipstick, resulting in a half-centimeter discrepancy due to oil-stained dust. The correct method is to wipe it clean, reinsert it fully, then pull it out and hold it horizontally to observe the oil level, which should be between Min and Max. In summer, I often notice the oil level is slightly higher due to thermal expansion, which is normal. Be cautious if the oil appears thin with bubbles, as it may indicate coolant contamination. Older models have a grid pattern at the end of the dipstick, while newer ones often use raised dots. Remember to add half a liter of oil when the level approaches the lower limit—overfilling can cause abnormal crankcase pressure and eventually lead to oil seal leaks.
Here's a practical tip: The most accurate oil level check is in the morning before starting the engine. Pull out the dipstick, wipe it clean with a non-woven cloth three times, insert it vertically all the way down, then pull it out to check where the oil film reaches. Modern cars often use 'L' and 'F' markings (Low/Full) instead of scales - as long as the oil mark is between these letters, it's safe. I learned the hard way: checking oil level on a slope once led to overfilling, resulting in blue smoke. The oil shouldn't cover more than three-quarters of the dipstick's length - if it does, you'll need to drain some. Be careful with cars having aged rubber sealing rings as loose fittings can cause false high readings. Plastic dipsticks are more prone to breakage than metal ones, so handle gently when cleaning off carbon deposits.
