Beware, I own an SR20 and recently had an oil change. After landing from my return from the oil change I noticed A LOT of oil dripping down the entire underside of my fuselage (several quarts worth). I opened the cowling cover and discovered the oil cap was OFF! Upon landing or Taxi the cap came off because 1) it was not tightened by the mechanic, OR, the gasket and flanges were insufficient to create a tight, secure fit and it vibrated loose and off. Interestingly, none of the oil discharged out of the oil filler tube, rather it was discharged out of the breather tube. I lost 3 quarts and thanked my lucky stars it happened on the ground, AFTER my flight. Has anyone ever experienced an oil cap vibrating off on it’s own??? I crimped down the flanges on the inside of the cap to create a tighter closure. Be sure to check your tension as a cap left off will discharge most (or all) of your oil in a hurry!. This sure seems dangerous! Any other expert opinions welcomed.
Yes, we have had that problem, and believe it was caused by the cap vibrating off. We were in the air when the oil pressure warning light lit up. Fortunately we were close to an airport and landed without any trouble. The belly of the plane was covered in oil, but we only took about 3.5 quarts to fill it back to 7 quarts. Testing the cap afterwards showed that it was loose, so we added a second gasket and now the fit is very snug and there have been no more problems.
Upon landing or Taxi the cap came off because 1) it was not tightened by the mechanic, OR, the gasket and flanges were insufficient to create a tight, secure fit and it vibrated loose and off.
Are you suggesting that you didn’t check the oil before takeoff?
Yes, we have had that problem, and believe it was caused by the cap vibrating off. We were in the air when the oil pressure warning light lit up. Fortunately we were close to an airport and landed without any trouble. The belly of the plane was covered in oil, but we only took about 3.5 quarts to fill it back to 7 quarts. Testing the cap afterwards showed that it was loose, so we added a second gasket and now the fit is very snug and there have been no more problems.
Interesting. I always check the dip stick and the oil filler cap as part of my preflight. Anytime on the ground before starting I also check thses two items underneath the filler door and look for anything else. In 4 years the oil filler cap is very snug.
On the SR20 the dipstick is not part of the oil cap.
Jim Knollenberg SR22 1904 N5PF
Thank you Jim. I have about 125 hours in an SR20 but I had forgotten that. (Or maybe I never checked the oil). If vibration is a problem that means that the cap could go 25-50 hours without being tightened.