oil light flashing intermittent at stop light

[t.sandin@comcast.net]

I recently had my oil changed on my 76 2002 and the oil light would intermittenly come on at stop signs and lights until i rev the engine to keep it off.

any ideas on what this might be?

[tech71]

A flickering oil pressure light at low RPM  usually indicates worn main bearings or oil pump. Assuming there's enough oil in there? Was the oil changed to a different weight?

Edited August 17, 2022 by tech71

[Mike Self]

What's your idle speed?  Should be around 8-900 rpm.  How many miles on the engine? 

 

If you have the OEM oil pressure warning light (i.e. you didn't add a gauge), the light will come on at .5 atmos, or 7 psi.  However, if you added a VDO gauge and retained the warning light circuit, it will come on at 1 atmos, or 14.7 psi.  From experience, my 204k mile engine didn't have the oil light come on at idle with the requisite 20W-50 oil and a VDO gauge.

 

Presume you're running 20w-50 oil, and that the folks that changed the oil put the requisite amount in (4.3 qts when the filter is changed).  If they put in 10W-30 (or, horrors 0W-20), you need to pay 'em a return visit for the correct oil.

 

mike

 

 

[Son of Marty]

All other things remaining the same I would be looking at what weight of oil was used, modern cars run a much lighter oil than our cars do.

[albatcha]

Another possibility is that the time the flickering light started happening is coincidental, and it's just a bad oil pressure switch or sensor. I had a vdo sensor stamped '73 and the warning light would flicker at idle and the needle of the oil pressure gauge would bounce up and down a lot, switched it with a new one and now the gauge reads more steady, it doesn't bounce below the low pressure mark, and the warning light never comes on.

 

I would say in order of easiness, check the oil level and weight first, then check the switch and the pressure, then look deeper into the engine after that.

[albatcha]

Also the vdo sensors lighting up at 14.7psi is not universally true. So be careful. I chose my sensor based on the specs and it stated the warning was at 7psi.