Oil Light flicker - made it go away

[Patrick Fant]

1956 Series 62 - engine and carb full R&R rebuild.  So after an hour of smooth highway driving, pulled up to light and the Oil light is flickering on.  Killed the factory AC compressor (instinctively - just to see) and the Oil light went off.  No more flicker.  Checked and Oil is full to top.  Sending switch replaced 3 months ago has been fine.  Never ever done this before/  ??  thoughts? pat fant #31723

[J. Gomez]

1956 Series 62 - engine and carb full R&R rebuild.  So after an hour of smooth highway driving, pulled up to light and the Oil light is flickering on.  Killed the factory AC compressor (instinctively - just to see) and the Oil light went off.  No more flicker.  Checked and Oil is full to top.  Sending switch replaced 3 months ago has been fine.  Never ever done this before/  ??  thoughts? pat fant #31723

Pat,

There are too many variables which you have not specified on your post.

Have you check the oil pressure with a gauge when the engine is fully warm?
Not trusting the sender/light, is the pressure within the specs?
Have you done anything to the oil pump or it still the OEM untouched?
What oil do you use standard or synthetic type?

If you have the standard A/C unit compressor it will put a small load on the engine while stop and in gear and A/C running, so the RPMs would be a bit lower. Remember the idle speed-up valve only works to increase the RPMs when in "P" or "N" NOT while in drive.

Also, the oil will drain (a few ounces) from the oil filter canister, so once the engine is running it will fill the canister back; so if you check the oil after a long period and it show correct it will be a bit lower level once is running to re-fill the filter canister. Just as FYI.

Good luck..!

[walt chomosh #23510]

pat,
  I believe my 55 owners manual tells the driver to put the trans in neutral when stopping and idling with the A/C on in an effort to "speed up" the motor.  Your motor is probably idling down allowing such a drop in speed that the oil light is flickering. Killing the A/C is allowing the motor to "speed up"..... walt...tulsa,ok 

[Patrick Fant]

Thanks very much gents for the info on the oil light flicker.  I am going to keep an eye on it but so far I believe the level is full enough but the idle RPM is a touch too low.  I am going to bump that up a little and watch it from there.  I run regular 30 weight, non-synthetic. many thanks for the observations - p

[Patrick Fant]

FORGOT -- also the oil pump is untouched, OEM as far as I know

[walt chomosh #23510]

Pat,
  Here's one for you and the oil flickering light. The connection between the oil pump pickup tube and the block requires a felt seal. Even thought the parts manual doesn't show one without it (and when the motor get 1quart low) it will suck air and put the light on. The damage it can lead to is rod bearings. There have been previous discussions on this site of this problem. I for one, have experienced it!....walt...tulsa,ok