Engine Lubrication After Oil Change

[flyer92]

I have changed the oil in my CJs and Wranglers for decades, but I always cringe when starting the engine for the first time after doing so. Obviously, there are a few seconds during which the engine isn't being completely lubricated, but I thought I recently heard about a procedure that allows you to send oil into the engine before turning it over. Something along the lines of shifting into neutral and turning the ignition on for several seconds before starting the Jeep normally. Just curious if anyone knows about this and might have some insight or experience with it. Thanks in advance and happy Jeepin'!

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[Left Field]

While holding the gas pedal to the floor, crank the engine for a few seconds to fill the oil filter and pressurize the oil galleries. The EFI software in our Jeeps mimics the old school 'hold it to the floor to clear a flooded engine' and shuts off the fuel.

Works on my 392, but guessing its across the line-up.

 

[flyer92]

While holding the gas pedal to the floor, crank the engine for a few seconds to fill the oil filter and pressurize the oil galleries. The EFI software in our Jeeps mimics the old school 'hold it to the floor to clear a flooded engine' and shuts off the fuel.

Works on my 392, but guessing its across the line-up.

OK, got it....wonder if the 3.6L has similar software logic. I assume that when cranking the engine, the gear shift is in neutral, right? If in park, it would just start normally, which is what we're trying to avoid.

 

[Left Field]

I haven't tried neutral, just got in, held pedal to the floor and pushed the button. It cranked without starting until I let off the gas pedal.

OK, got it....wonder if the 3.6L has similar software logic. I assume that when cranking the engine, the gear shift is in neutral, right? If in park, it would just start normally, which is what we're trying to avoid.

 

[mwilk012]

OK, got it....wonder if the 3.6L has similar software logic. I assume that when cranking the engine, the gear shift is in neutral, right? If in park, it would just start normally, which is what we're trying to avoid.

No just start it normally but with the gas pedal on the floor. Not slightly off the floor, completely maxed out. Push the brake pedal with your left foot, and push the start button. Let it crank for a few seconds, then let go of the gas pedal, it will fire right up.

 

[Old Jeeper]

I have changed the oil in my CJs and Wranglers for decades, but I always cringe when starting the engine for the first time after doing so. Obviously, there are a few seconds during which the engine isn't being completely lubricated, but I thought I recently heard about a procedure that allows you to send oil into the engine before turning it over. Something along the lines of shifting into neutral and turning the ignition on for several seconds before starting the Jeep normally. Just curious if anyone knows about this and might have some insight or experience with it. Thanks in advance and happy Jeepin'!

Unless you are leaving your Jeep for months at a time there is no need to concern yourself on drain down.

2 Things come into play:

1) Today modern oils have a high degree of what is called stickiness in other words the oil adheres to the cylinder walls. This comes from longer chain molecules found in Synthetic oils...

HOW & WHY.

2) The walls are Cross-hatched and it's this procedure that allows oil to reside in the cross-hatching. This is a mechanical dressing of the walls of the cylinders.

You have NOTHING to be concerned about.


Standard 45-degree Cross Hatching in the cylinder walls of modern cars.

 

[58Willys]

I’ve dismantled several motors over the the years that have sat for weeks or months, there was still plenty of oil everywhere. No need to worry.

 

[flyer92]

I’ve dismantled several motors over the the years that have sat for weeks or months, there was still plenty of oil everywhere. No need to worry.

OK thanks for the great insight. I always thought that there should be residual oil sticking to the parts, so I feel much better knowing this for certain now. However, I don't think it's a bad idea to squirt more oil in the cylinders either. Knowing both of these aspects are useful, so it's just a matter of personal preference. Much appreciated!

 

[B&ZRubi]

I thought it was hold the brake and gas pedal to the floor, then hit the start button to get it to turn over but not start. I will have to try just the gas pedal and see if it does the same thing on my 2020 JL.

 

[NWJeepr]

A lot of people pre-fill their oil filters for this exact reason on other engines. I don't think that's really possible on the 3.6, not without an aftermarket oil filter setup.

As for anecdotal evidence, I've seen engines last hundreds of thousands of miles without pre-filling filters or cranking the engine over without starting to build oil pressure.

If an engine sat for a really, really long time, that's another story. But for a routine oil change, any potential wear is negligible.

 

[1BadManVan]

I thought it was hold the brake and gas pedal to the floor, then hit the start button to get it to turn over but not start. I will have to try just the gas pedal and see if it does the same thing on my 2020 JL.

You have to hold both, they mean you add to the procedure by holding the gas pedal as well

 

[B&ZRubi]

You have to hold both, they mean you add to the procedure by holding the gas pedal as well

It read like you just hold the gas pedal.

 

[tk1700]

A lot of people pre-fill their oil filters for this exact reason on other engines. I don't think that's really possible on the 3.6, not without an aftermarket oil filter setup.

As for anecdotal evidence, I've seen engines last hundreds of thousands of miles without pre-filling filters or cranking the engine over without starting to build oil pressure.

If an engine sat for a really, really long time, that's another story. But for a routine oil change, any potential wear is negligible.

I believe the filter on the 3.6 drains each time you shut the engine off. So, every time the 3.6 is started after it has sat for a while the filter has to be refilled.

 

[CarbonSteel]

I believe the filter on the 3.6 drains each time you shut the engine off. So, every time the 3.6 is started after it has sat for a while the filter has to be refilled.

It does not according to the oil lubrication diagrams I have seen. The tip on the end of the filter serves as the anti-drainback valve.

This can be evidenced when you drain the oil during an oil change by dumping the pan first, then pull the filter--more will drain out.

 

[speedymart]

I have changed the oil in my CJs and Wranglers for decades, but I always cringe when starting the engine for the first time after doing so. Obviously, there are a few seconds during which the engine isn't being completely lubricated, but I thought I recently heard about a procedure that allows you to send oil into the engine before turning it over. Something along the lines of shifting into neutral and turning the ignition on for several seconds before starting the Jeep normally. Just curious if anyone knows about this and might have some insight or experience with it. Thanks in advance and happy Jeepin'!

It's in your head. All the rotating components maintain a layer of oil when turned off. The engine isn't submerged in oil, every single time you start the engine it's essentially the same thing as doing what you're stating after and oil change.

Don't worry about it

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