ASVAB (Armed Services Vocational Aptitude Battery)Auto and Shop Information (AS)Medium
A technician is performing an engine oil change. After draining the old oil and replacing the filter, they add new oil. What is the correct procedure for checking the oil level to ensure it is at the proper mark?
- AStart the engine, let it run for a few minutes, then check immediately with the engine running.
- BCheck immediately after adding oil, with the engine off.
- CStart the engine, let it run for a few minutes, then turn it off and wait 5-10 minutes before checking.
- DCheck after a long drive, with the engine off and cool.
Show answer & explanationAnswer & explanation
Correct answer: C. Start the engine, let it run for a few minutes, then turn it off and wait 5-10 minutes before checking.
After adding oil, the engine should be run briefly to circulate the new oil and fill the filter. Then, the engine needs to be turned off and allowed to sit for several minutes for the oil to drain back into the oil pan before an accurate level can be read on the dipstick.
Why the other options are wrong
- A. Checking with the engine running will give a falsely low reading because oil is actively being pumped throughout the engine and not fully in the pan.
- B. Checking immediately after adding oil will give a falsely high reading as the oil has not yet circulated through the engine and filter.
- D. Checking after a long drive and allowing it to cool is unnecessary and inconvenient; the 5-10 minute wait after running is sufficient for accurate measurement.
Engine Oil Level Check
The procedure to accurately determine the amount of engine oil in the crankcase using the dipstick.
- Vehicle must be on level ground.
- Engine should be warm but off for 5-10 minutes.
- Wipe dipstick clean, reinsert, then check.
Memory trick: Run, rest, then read right.