What actually happens when you overfill your motor oil? (w/ transparent oil pan)

The level of anxiety i go through when overfilling my engine just a little over the max level, thinking it's gonna explode any moment, this guy is a hero

For those who are looking for a problem and not seeing it, the problem is the foaming. As the oil level rises, the oil foams more violently, and this introduces air pockets to bearing surfaces inside the engine. On top of that, aerating the oil pump lowers functional oil pressure by introducing compressible air into otherwise non-compressible fluid, and makes it harder for the pump to maintain a prime while operating.

decades of conversations with professional mechanics, smart backyard mechanics, and me, who regularly works on my cars and friends' cars, and i've never been given a straight or consistent answer. i've always enjoyed this channel, but that was fucking fantastic. cheers, from me in Alaska to you in Siberia!

I was in Atlanta 25 years ago at the Lenox Mall and a lady parked next to us couldn't get her car started. I offered to have a look and raised the hood to check around. It sounded weird when cranking. I removed the oil fill cap and oil started to run out from the engine. The lady said her son had filled it to the top like he does with his push lawn mower. Can't imagine how many quarts (or gallons) the son put in the engine. I hadn't thought about this in a long time until now watching your video. Thanks for creating this visual example. Cheers!

Back in the 80’s when me and my mates started driving I dropped round my mates house, he had the bonnet of his Vauxhall Chevette open and was staring into the engine bay. By his feet were 3 5 litre Duckhams oil tins, he had already poured 10 litres of oil and was starting on the 3rd tin!!! Seems he was waiting until it reached ‘the top’ and then he’d know it was full!!! He wasn’t the brightest of my mates! I drained it out for him and introduced him to the dipstick!

Needed an oil pressure gauge to show pressure drop

A clear oil pan and a cutaway in the block? Brilliant! I've never seen this in a functioning engine. Thank you. I was so concerned once when I added oil past the upper level limit on the dip stick that I siphoned the excess out. Now I realize that I need not have worried.

I didnt expect this in my recommendation feed as I'm nearly clueless as a mechanic, but as a scientist, as a car owner and just overall curious person, that was really great! I always enjoy looking at the "inside of things" and it's fantastic that we can now make transparent engines to make demonstrations like this one. Super job from you guys, although you made me anxious near the end with that crazy amount of oil LOL 😂

I laughed when he kept saying “more oil”, after what I thought was beyond the fill capacity. He’s a mad scientist. Love his videos 😊

2 things happen. 1. power is reduced due to the crank hitting the oil and picking it up. This is the reason race engines use dry sump systems or windage trays and scrapers. 2. The foaming action of the oil is increased not allowing air to dissipate out of the oil causing cavitation around the oil pump pick up tube, thus reducing oil pressure because of air in the system which reduces the film of oil on the bearings and causing extern wear. Garage 54 is what hot-rodding in the US use to be! Great and fun channel.

This is the best mechanic channel on YouTube. To understand why things should be done in the correct way. Thanks and congrats.

I was always afraid of the fact, when I pour in oil more than required at times and remained uneasy while driving ... But I must thank you for putting me at ease regarding pouring "bit" more than required ..... Thank you Man ..

This man answering the hard questions in life 🍻

Thanks guys. I just added an extra 5 quarts just to be safe.

A buddy of mine had a Trailblazer with a 5.3 V8 engine. Those engines are notorious for the O-ring going bad at the top of the pick-up tube. It happens to be at the front of the engine, so during acceleration or on an incline, oil pressure would drop, since oil moves backward in those situations. We put a scanner on there that told us the realtime oil pressure in psi, then we jacked the front of the car up until pressure started to drop. We added an additional quart of oil to get the pressure back to normal, then we jacked it up some more until it dropped again. We added a second extra quart, then jacked it up again, and this time it was high enough that we didn't think the car would ever get on an incline that steep. We added the third extra quart to get the pressure back to normal. After that, we simply added the 3 additional quarts at every oil change. That was a long term test of about 70k miles for a total of 230k on the vehicle when he finally sold it. As long as that O-ring was submerged, it couldn't draw any air and the pressure stayed normal. That was only 3 quarts over full, and it was a bigger engine so I never expected any adverse effects. We could have dropped the front axle, pulled the pan and replaced that O-ring, but to add 3 quarts and get the exact same result just made sense. Apologies to all the OCD mechanics out there scoffing at the "rigged" fix, lol.

The patience, knowledge and integrity behind these videos is off the charts

This guy answers all the questions I've had for the last 25 years as an automotive machinist and engine/drivetrain rebuilder.

G54 is the worlds most awesome car related youtube channel. No joke. Thank you BMI for translating for a wider audience!

I just witnessed execution of the most thorough engine flush ever performed!

You just answered a question I have had since high-school autoshop classes! Thank you!!