HELP Low Oil pressure warning
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 766
Likes: 42
From: Laguna Beach CA
HELP Low Oil pressure warning
Low oil pressure warning came on during startup over the weekend. Was on for a couple of seconds and then fluctuated around 8psi before going to normal. Once I started driving oil pressure fluctuated quite a bit but stayed above 30psi. My car has a ported oil pump and typical pressure is around 40psi. I topped it off and let it sit overnight. The next day I did not drive the car but did start it to move it to a resting position in the garage. This time the low oil pressure came on again but the car quickly settled to normal and the pressure stayed pretty consistent. Car has cam and headers so it is difficult to decipher from the usual valve train noise. Car is idling normal and ran great all weekend. My first thought is to drain the oil and filter and inspect for any material that may have temporarily caused a blockage. Is it possible that the oil sending unit could be going bad, I’ve read that when they go they read high not low? No codes. Thoughts?
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
When the oil pressure sensor fails --it usually sticks at the max oil pressure like 99 PSI
I have had some oil filters clog after some internal engine mods--Fram
(sorry) seems to be te worst--I would use either an AC/Delco-K&N or Mobil One filter
Anioher common sourse for losing oil pressure is after doing mods and removing the oil pump--the O-ring that seals the oil pick-up tube to the pan gets pinched--See it all the time--Would cause the pump to lose prime and suck up some air resulting in low pressure til it primes again--
A good rule of thumb is to have at least 10 PSI of pressure for each 1000 RPM's so at 6000 RPM WOT you should have about 60 PSI---I would be more concerned with this---IF you don't get at least 50-60 PSI warm or cold at 6000 it could point to something else
I have had some oil filters clog after some internal engine mods--Fram
(sorry) seems to be te worst--I would use either an AC/Delco-K&N or Mobil One filter
Anioher common sourse for losing oil pressure is after doing mods and removing the oil pump--the O-ring that seals the oil pick-up tube to the pan gets pinched--See it all the time--Would cause the pump to lose prime and suck up some air resulting in low pressure til it primes again--
A good rule of thumb is to have at least 10 PSI of pressure for each 1000 RPM's so at 6000 RPM WOT you should have about 60 PSI---I would be more concerned with this---IF you don't get at least 50-60 PSI warm or cold at 6000 it could point to something else
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
You can opt to have a dealer do a mechanical oil pressure test therefore verifying the facts. Hopefully you just have a bad sender. Any noise out of the engine when the pressure dropped off?
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 766
Likes: 42
From: Laguna Beach CA
When the oil pressure sensor fails --it usually sticks at the max oil pressure like 99 PSI
I have had some oil filters clog after some internal engine mods--Fram
(sorry) seems to be te worst--I would use either an AC/Delco-K&N or Mobil One filter
Anioher common sourse for losing oil pressure is after doing mods and removing the oil pump--the O-ring that seals the oil pick-up tube to the pan gets pinched--See it all the time--Would cause the pump to lose prime and suck up some air resulting in low pressure til it primes again--
A good rule of thumb is to have at least 10 PSI of pressure for each 1000 RPM's so at 6000 RPM WOT you should have about 60 PSI---I would be more concerned with this---IF you don't get at least 50-60 PSI warm or cold at 6000 it could point to something else
I have had some oil filters clog after some internal engine mods--Fram
(sorry) seems to be te worst--I would use either an AC/Delco-K&N or Mobil One filter
Anioher common sourse for losing oil pressure is after doing mods and removing the oil pump--the O-ring that seals the oil pick-up tube to the pan gets pinched--See it all the time--Would cause the pump to lose prime and suck up some air resulting in low pressure til it primes again--
A good rule of thumb is to have at least 10 PSI of pressure for each 1000 RPM's so at 6000 RPM WOT you should have about 60 PSI---I would be more concerned with this---IF you don't get at least 50-60 PSI warm or cold at 6000 it could point to something else
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 766
Likes: 42
From: Laguna Beach CA
I might have to take it in for a mechanical oil pressure check if the problem persists. I didn’t notice any additional noise.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Minimum for the engine is 6psi. If it drops below, I would think you'd be hearing clattering right away or within a few seconds. If not, then check the sending unit to see if the connector is on all the way or not. You can replace the sender just in case but the mechanical test will verify the pump.
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 766
Likes: 42
From: Laguna Beach CA
Minimum for the engine is 6psi. If it drops below, I would think you'd be hearing clattering right away or within a few seconds. If not, then check the sending unit to see if the connector is on all the way or not. You can replace the sender just in case but the mechanical test will verify the pump.
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 766
Likes: 42
From: Laguna Beach CA
Problem solved
I was thinking I was going to have to replace the oil pump as the problem persisted during a mid week startup and then Saturday morning I drove the car to the gym and on the way home I stopped by Jiffy Lube. I had them change the oil filter, not an oil change just the filter. As soon as I pulled away oil pressure went to normal and idol fluctuations stopped. I thought this was too good to be true so I drove straight home and let it sit for an hour. Went back in the garage fired it up and oil pressure shot right up to 40psi and stayed there. Drove the car all day Sunday and not one problem. Problem solved and I learned my lesson with cheap oil filters. This next weekend I will be doing an oil change myself and replacing the Jiffy Lube oil filter with a Mobil One filter.
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Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Very interesting as it sounds like the filter might have collapsed internally or something. I know you'll be keeping a close watch on the pressure readings for a long time to come.
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 766
Likes: 42
From: Laguna Beach CA
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
I was thinking I was going to have to replace the oil pump as the problem persisted during a mid week startup and then Saturday morning I drove the car to the gym and on the way home I stopped by Jiffy Lube. I had them change the oil filter, not an oil change just the filter. As soon as I pulled away oil pressure went to normal and idol fluctuations stopped. I thought this was too good to be true so I drove straight home and let it sit for an hour. Went back in the garage fired it up and oil pressure shot right up to 40psi and stayed there. Drove the car all day Sunday and not one problem. Problem solved and I learned my lesson with cheap oil filters. This next weekend I will be doing an oil change myself and replacing the Jiffy Lube oil filter with a Mobil One filter.
Mobil 1 EP Synth oil and filter all the way!
