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The Tech Nerd in Corvette Magazine published a query about whether the Clear Flood Mode can be used as a pre-oiler. The response was interesting. The feature is designed primarily to clear the engine of excess fuel. To activate, press the accelerator pedal to the floor and press the start button. The engine will crank but will not start, as it clears any excess fuel. However, he cites road racer Donny Yorke, who uses this feature as a pre-oiler before start up by cranking for 10 seconds and resting for 10 seconds, repeating three times. By doing this the oil system will be pressurized to 25 psi before you actually start the engine. This system apparently has been in all Corvettes since 1982 when the cross-fire injection was introduced.
I searched the 2023 Owners Manual for the word flood. It only appears on time. In the 2020 Service Manual I found this:
"Clear Flood Mode
If the engine floods, the engine can be cleared by pressing the accelerator pedal down to the floor and then cranking the engine. When the throttle
position sensor is at wide open throttle (WOT), the ECM reduces the fuel injector pulse width in order to increase the air to fuel ratio. The ECM
holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide
open, the ECM returns to the starting mode."
Here is the Owners Manual discussion about a flooded engine:
Neither description in post 2 indicates the the car "will not start". The Owner's Manual descriptions says "When it start.....". And the Service Manual description says it reduces the injector pulsewidth to increase the air to fuel ratio. I would not routinely attempt to start the car with the pedal floored.
The question wasn't about starting a flooded car, it was about using that procedure to boost oil pressure before starting. Suffice it to say, it is completely unnecessary, of little or no benefit, and certainly causes additional battery drain and starter wear. It's also wasted time.
I searched on flood because Clear Flood was the proposed way to pressurize the oil by cranking the engine ostensibly without it starting. Neither the procedure I found in the Owners Manual, nor the one in the Service Manual would result in cranking without starting. So it would not work for that purpose, regardless.
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Your C8 runs on very thin 0w 40 or 5w 30 SYNTHETIC OIL. It flows very quickly even on a cold start. Pre oiling is a decades old throw back to straight weight dino oils. It is used in a very few special applications today of which your C8 is not one. . As mentioned above it will burn out your starter and battery. Do not even think of doing this. Period !
I'm not quite sure how you would flood the engine in the C8. It's not like a carb with an accelerator pump spraying raw gas down the throat as you pump the gas pedal over and over. It's a direct injection system that puts precisely measured, finely atomized fuel directly into the cylinder ONLY on the compression stroke. I guess if you disconnect the spark plugs and keep cranking the engine, maybe. But under normal circumstances it seems extremely unlkely.
The question wasn't about starting a flooded car, it was about using that procedure to boost oil pressure before starting. Suffice it to say, it is completely unnecessary, of little or no benefit, and certainly causes additional battery drain and starter wear. It's also wasted time.
That parallels my thought: why are you doing this?
The Tech Nerd in Corvette Magazine published a query about whether the Clear Flood Mode can be used as a pre-oiler. The response was interesting. The feature is designed primarily to clear the engine of excess fuel. To activate, press the accelerator pedal to the floor and press the start button. The engine will crank but will not start, as it clears any excess fuel. However, he cites road racer Donny Yorke, who uses this feature as a pre-oiler before start up by cranking for 10 seconds and resting for 10 seconds, repeating three times. By doing this the oil system will be pressurized to 25 psi before you actually start the engine. This system apparently has been in all Corvettes since 1982 when the cross-fire injection was introduced.
Seeing as everyone else keeps mentioning carburetors and fuel, I'll answer.
Yes, nothing wrong with doing a clear flood after doing an oil change. I do it on all of my vehicles as it never hurts to ensure oil has reached all the good places before firing it up. Do you have to do it 3 times? No. Just hold the pedal to the floor, push the start button and let it crank for 10-15 seconds, then let go of the pedal and it will fire up. Starter can take it too, so don't worry about "burning it up". Its not like you need to clear flood every time you start it, just after an oil change.
Seeing as everyone else keeps mentioning carburetors and fuel, I'll answer.
Yes, nothing wrong with doing a clear flood after doing an oil change. I do it on all of my vehicles as it never hurts to ensure oil has reached all the good places before firing it up. Do you have to do it 3 times? No. Just hold the pedal to the floor, push the start button and let it crank for 10-15 seconds, then let go of the pedal and it will fire up. Starter can take it too, so don't worry about "burning it up". Its not like you need to clear flood every time you start it, just after an oil change.
Have you tried it in the C8, and does it work as described by the OP. I found the description of the Clear Flood Mode in the 2020 Service Manual, and it differs from what the OP said. That is, in the Service Manual it says nothing about pushing the start button, and it also says that it modifies the signal to the injectors to increase the air fuel rations. Does not say anything about cutting off the fuel or the igntion. If pushing the button does that, it is not described in the Service Manual. Here is the description from the Service Manual:
"Clear Flood Mode
If the engine floods, the engine can be cleared by pressing the accelerator pedal down to the floor and then cranking the engine. When the throttle
position sensor is at wide open throttle (WOT), the ECM reduces the fuel injector pulse width in order to increase the air to fuel ratio. The ECM
holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide
open, the ECM returns to the starting mode."
Clear Flood Mode
