Update: Building oil pressure before firing.

[Nfs1000f]

With my 1st start around the corner after 4 months of hibernation, will spinning the engine without starting it build oil pressure?
I recall a post I could not find mentioning that holding down the clutch and gas pedals at the same time before hitting the start button will prevent the engine from firing.

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[jmn444]

guessing it would but you still have all of the parts moving so I don't see why you'd do this....

 

[SVTinAR]

No need for that especially with modern oil chemistry. I have several old cars that often sit for 4 months and sometimes more and I prefer to fill the carb bowls with gas before starting and prime the motor so that it will start on the first cylinder/plug firing and instantly build full oil pressure.

 

[galaxy]

Way. Overthinking.

 

[Nfs1000f]

Way. Overthinking.

Yes, I know. It’s the only thing I excel at.

 

[Demonic]

If I recall correctly the consensus was that without an actual pre-oil system like an Accusump, the rotations from the starter aren't enough to build significant oil pressure.

 

[Alain]

Yes, I know. It’s the only thing I excel at.

Ditto

 

[honeybadger]

If I recall correctly the consensus was that without an actual pre-oil system like an Accusump, the rotations from the starter aren't enough to build significant oil pressure.

This is correct.

 

[Nfs1000f]

Engineer?

No. I did get an AS degree in engineering, but never worked as one.

 

[GrapeApe]

Yes, hold the clutch and accelerator down while starting and you will eventually see 5-10 psi at the gauge. I like to do this if my car has sat for a month or more. Also an overthinking ME lol.

 

[shogun32]

20 rotations at 'no/low' pressure to help prime all circuits is a lot better than 300 that also have combustion effects. There won't be pressure under the cams or big journals but the oil will be freshly applied.

 

[jmn444]

20 rotations at 'no/low' pressure to help prime all circuits is a lot better than 300 that also have combustion effects. There won't be pressure under the cams or big journals but the oil will be freshly applied.

eh.... if it was "a lot" mfg's would build in a delay on the ignition for every start IMO. but do whatever makes you happy.

Is there not some sort of check valve in the pump to keep the pressure side primed? I would think the drain back would be limited somehow...

 

[Nfs1000f]

I got a definitive answer to my question. My car has been sitting for four months and today I could not resist so I took her out. Prior to firing the engine I did depress the clutch and the pedal to the floor, the engine spun for 5 to 10 seconds, built 100 psi of oil pressure and then shut down itself. I started it normally and the psi went back 100 psi. Whether there is a benefit to doing this or not is still up for debate which I’m not here to do.

Additional observations:
I had no flat spotting on my tires from sitting four months in an unheated garage with the tire pressure at 42 psi. Halfway through the four months I did jack the car up and rotate the tires 90°. Probably was not necessary.

As I expected the oil life is down to 63% after replacing the oil prior to putting it away and resetting it to 100%. The 63% should get me through the season.

I checked the oil before turning it over and it was halfway between the hashmarks. My car has always shown halfway after an oil change. Checked it 15 minutes after my drive and it was showing full.

 

[Alain]

100 PSI of oil pressure prior to starting is pretty substantial.

I would say that 100 psi is enough to have a positive impact on a cold start after sitting for an extended period of time.

I did this with my Hellcat last year in the spring. Gonna do it with all three cars this spring. Just need to figure out how to do it in the ZLE.

 

[cdh027]

Anyone know if this technique can be done on a M7 C7 Z06 as well?

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