Q: Should one read the oil level with the dip stick screwed in or just resting on the threads?
Gary Brown, via email
A: Gary, I’m glad you asked this question even though I can see the boys in the hangar beginning to smile about it. First of all, it’s not quite as simple as it sounds.
If you stop and think about it, how many different engine models and airframe installations do you think there are out there? The combinations would probably blow your mind, and then the next question that comes to mind is how many different dipsticks would be needed.
The choice of dipsticks actually begins when the aircraft/engine design work begins. The airframe manufacturer takes the lead in determining which dipstick will be used because he knows how the specific engine will be mounted and the number of degrees tilt, etc., the engine will have or whether the engine will be utilized on a twin-engine aircraft.
Each dipstick must be calibrated taking all of these factors into consideration. It is certainly not a case of one size fits all.
So, for those of us that believe close is good enough, it’s probably okay to check the oil with the dipstick just resting on the threads. But for those of us who suffer from OCD/ADD, we will certainly want it screwed down tight when checking our oil.
We also shouldn’t forget that not all dipsticks screw in because some use a cam-action type method to secure them in place. It’s this type that most folks would properly secure when checking the oil.
This all may sound like a bunch of gibberish, but it’s an important part of using common sense and setting standards for yourself by doing it the same way each time the oil is checked.
It doesn’t makes that much difference which way you do it, but rather that you do it the same way each time.