Low Oil Pressure
12-06-2009, 06:59 PM
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Low Oil Pressure My oil pressure has gone down to about 20. At first, the pressure was a little under normal at idle, maybe 45 while cold and 30 while warm. It would go up to about 40 again once the RPMs increased. It went down to about 25 when warm, so I decided to change the oil pressure sending unit. Turned it on once I was done, and still the pressure stayed low. I haven’t driven it much since then.
Now when I start it, it stays at 20 whether the car is cold or warm and the pressure doesn’t vary with RPMs anymore. The engine sounds normal. So what do I do now? Oil pump?
Now when I start it, it stays at 20 whether the car is cold or warm and the pressure doesn’t vary with RPMs anymore. The engine sounds normal. So what do I do now? Oil pump?
12-07-2009, 05:47 AM
#2
in the older ls1s (98-00) the relief valve bore had sharp edges that the relief check ball could start to hang up on..... I'd do the pump just for piece of mind. also for a few extra bucks I'd jump up to a hi volume pump and double roller timing set while you have the front of the motor opened.
it would be a good time for a cam swap too
it would be a good time for a cam swap too
12-07-2009, 10:07 PM
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well i had pretty much the same problem with mine after i got it back from the dealership for an overhaul. well i changed the oil and oil filter and it fixed the problem. oil preasure is now normal again. no telling what kinda oil filter an oil the dealership put in it, probably the cheapest they could find...
12-08-2009, 08:42 PM
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It has 85,000 miles. Can it be a bearing? The car runs well and it doesn't make any knocking noises. The oil pressure has slowly been decreasing. I have revved it up quite a bit. Doesn't knocking usually start as soon as a bearing goes bad?
12-08-2009, 09:52 PM
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Double check with a mechanical gauge before replacing any more parts. Its easy to drill and tap the port above the filter, check your pressure then buy a 1/8 npt plug to plug your tapped hole. Never count the factory gauge as the end all be all truth.
12-09-2009, 11:45 PM
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Is there a write up on how to install the mechanical gauge? I’ve searched for it but I can’t find it.
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12-10-2009, 12:41 AM
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i think you should at least change your oil filter, it is possible that it can collapse. and i had a problem with my oil pump on my 99 car, 92k miles and the relief valve stuck in the open position so i was at zero psi. but 1 day prior to that happening my oil psi went down to almost 20 hot idle which it has never been below 40. it is very possible your pump could be getting ready to crap out
12-10-2009, 09:49 AM
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Its a 2 bolt cover directly above the oil filter with a short tube pointing up. Unbolt it, drill through with the correct size bit, then tap with a 1/8 27 NPT tap and screw in your mechanical gauge's hose. Then plug the hole with a 1/8 27 NPT plug after you are done. Ýou can buy the bit and tap at o reillys.
12-10-2009, 03:15 PM
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Last edited by NC98Z; 11-12-2010 at 01:15 PM.
12-11-2009, 09:01 AM
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LS oil pumps don't last long, I just replaced mine with a stock LS2 and Pressure went up 10-15 psi across the board..
Aluminum housing with steel gears and the fact the oil pump sits out of the oil pan and drains when motor is off doesn't help.
Aluminum housing with steel gears and the fact the oil pump sits out of the oil pan and drains when motor is off doesn't help.
12-26-2009, 04:14 PM
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Okay, so I checked it out with a mechanical oil gauge and still had 20, which is a little different than what my dash gauge told me. I ordered a TSP ported LS6 pump, installed it and still read 20. I’m expecting main bearings, but the car doesn’t knock so before I do anymore work I need you guys to help on diagnosing this problem further. I was reading another thread and a guy with a similar problem said it was his cam retaining clip. Any suggestions on what to do next? What else might it be?
12-26-2009, 04:18 PM
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Okay, so I checked it out with a mechanical oil gauge and still had 20, which is a little different than what my dash gauge told me. I ordered a TSP ported LS6 pump, installed it and still read 20. I’m expecting main bearings, but the car doesn’t knock so before I do anymore work I need you guys to help on diagnosing this problem further. I was reading another thread and a guy with a similar problem said it was his cam retaining clip. Any suggestions on what to do next? What else might it be?
12-26-2009, 04:26 PM
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Yep. I changed my oil and i got a new oil filter. The mechanical gauge still said 20 psi after the new oil pump. I made sure that the o ring stayed on perfectly. I used the blue o ring that came with my TSP LS6 pump.
12-27-2009, 12:41 PM
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My oil pressure has gone down to about 20. At first, the pressure was a little under normal at idle, maybe 45 while cold and 30 while warm. It would go up to about 40 again once the RPMs increased. It went down to about 25 when warm, so I decided to change the oil pressure sending unit. Turned it on once I was done, and still the pressure stayed low. I haven’t driven it much since then.
Now when I start it, it stays at 20 whether the car is cold or warm and the pressure doesn’t vary with RPMs anymore. The engine sounds normal. So what do I do now? Oil pump?
Now when I start it, it stays at 20 whether the car is cold or warm and the pressure doesn’t vary with RPMs anymore. The engine sounds normal. So what do I do now? Oil pump?
12-27-2009, 01:07 PM
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It should live with that amount of psi, i wouldnt want it to go under 20psi tho. i think your supposed to have 7psi to every 1k rpms for one to live safely so i think your ok for right now. what oil are you running??
12-27-2009, 01:10 PM
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10w30 mobile syn with 1 can of restore and ac delco filter
Last edited by 210z28; 12-27-2009 at 01:17 PM.
01-05-2010, 12:58 AM
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I have also been noticing low oil pressure. It fluctuates a bit from 35-40psi when warm... I took it up to 5k today and it wouldn't budge past 50psi, lower than before. Time to take it easy and keep on eye on my oil pressure. BTW, im using penzoil synthetic 10w-30.