Low oil pressure after warm
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From: Ft. Worth, TX
Low oil pressure after warm-FIXED After the car warms up I get very little oil pressure. It seems to be getting worse over the past year or so. Has anyone else had this problem and fixed it? Thanks,
Wes
EDIT: Did an oil analysis and that showed everything was normal so I replaced my stock oil pump (55K miles) with a TSP ported and switched to 15W-50 and my pressure is great, even after warm. I also replaced the O-ring which looked a little worn but I wouldn't have blamed it as the culprit. When warm I see ~45psi at idle and ~70psi at WOT. Thanks guys.
Wes
EDIT: Did an oil analysis and that showed everything was normal so I replaced my stock oil pump (55K miles) with a TSP ported and switched to 15W-50 and my pressure is great, even after warm. I also replaced the O-ring which looked a little worn but I wouldn't have blamed it as the culprit. When warm I see ~45psi at idle and ~70psi at WOT. Thanks guys.
Last edited by WMSuperSport; May 26, 2004 at 12:08 PM. Reason: update
oil pump may be going bad. Atleast your getting a warning. Mine went bad, and took out a low mile (14,400) engine. I would change the oil, cut open the filter, and have an analysis done. Of course a new oil pump may be needed as well.
Somebody else chime in....I'm no expert.
Somebody else chime in....I'm no expert.
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From: Ft. Worth, TX
On startup oil pressure is about halfway up the guage, then once warm (a few minutes later) it will drop closer to the red than 25psi. I would guess around 10 psi or so at idle. At WOT is doesn't even reach 25 psi.
Thanks for the help,
Wes
Thanks for the help,
Wes
I have the same problem-just started Friday out of nowhere. Had been holding great pressure, now it is exactly as you describe. This motor only has about 700 miles on it. Friday night I changed the oil and that didn't help. Today I hooked up a mechanical gage and it reads the same so there is definitely a pressure problem. It has to be the pump, or bearing damage. I don't have time to pull the pan til at least next weekend, so I won't know anything til then, but I am watching this thread closely!!
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On The Tree
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From: grimsby, ont. can.
My car is doing almost the same thing. Just when i give it gas the pressure rises and goes back down. When its cold, it stays up, but soon as you drive awhile and it gets hot, it reads lower. Just between half and 1/4. I'm doing my waterpump within the next couple of weeks and so i'll try a new oil pump while i'm there. I hope its not the bearings. 
Considering the pump problems with these motors, I's supsect that it's going. But they usually just quit. What you describe sounds like a blockage, or a spun bearing. Do you have a stethascope? If so listen to the motor. You should have a noticable clunking sound if a bearing is gone. Unless it's a cam bearing. Then you get exactly what you are describing. Low pressure & NO noise. The old 390 Ford motors were notorious for this, but I have not heard about the LS1s doing it....until now.
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From: Ft. Worth, TX
Thanks for all the replies. I'm thinking about doing the oil filter analysis because I believe that will tell me if my bearings are wearing out. Anyone know where I can get an analysis performed at?
Thanks
Thanks
Mine will drop to about 30-35 or so when it gets real hot. I just flip on the radiator fans and it will climb back up to 40 or so at idle.
I currently use Valvoline SynPower 5W-30 ... on Patman's recommendation I am gonna switch over to Mobil 1 0W-40 ... supposedly a better oil choice for the LS1.
If you are only pulling 25 psi of oil pressure at WOT, you need to quit driving your car NOW and replace the oil pump at a minimum. You may have also trashed one or more of the bearings with that little oil pressure at WOT...you should be pushing at least 60+ psi at WOT.
I currently use Valvoline SynPower 5W-30 ... on Patman's recommendation I am gonna switch over to Mobil 1 0W-40 ... supposedly a better oil choice for the LS1.
If you are only pulling 25 psi of oil pressure at WOT, you need to quit driving your car NOW and replace the oil pump at a minimum. You may have also trashed one or more of the bearings with that little oil pressure at WOT...you should be pushing at least 60+ psi at WOT.
Staging Lane
Joined: Aug 2003
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From: Belle Vernon, PA
when I first start my car the idle pressure is 45. After I dirve around and it is warm the idle is about 20, if I have to sit for a while, the pressure drops to 12-20.
Once I'm back and the highway @ 60mph it runs about 38-42.
Once I'm back and the highway @ 60mph it runs about 38-42.
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Mikez28, mine does the same, how long have you been driving around like that?
I plan to replace the sending unit, and if that doesn't help I'll replace the pump and o-ring, and if that doesn't help-it looks like a rebuild. Anyone know of any job openings in DFW?
I plan to replace the sending unit, and if that doesn't help I'll replace the pump and o-ring, and if that doesn't help-it looks like a rebuild. Anyone know of any job openings in DFW?
I drove mine yesterday for the first time since it started this crap. Last Sunday I verified low pressure with a mechanical gauge so there is some prob for sure. Anyways, when it is cold it holds about 40 idling and if I rev it it will go to 50 or so-pretty close to where it always ran. But when it warms up it eventually drops to 20, even on the highway and even dropping in into 2nd and 70mph it stays on 20 (maybe it goes up to 25) but it stays low. I found something weird-if I am cruising at a steady speed-say 70-and give it a little throttle like accelerate up to 75 then let off the gas, the ol pressure rises maybe 5 lbs then when I rest my foot back on the gas it goes back to 20! I guess if I ever get time I will try to put a new pump in it.
May car was also doing the same thing, not as bad as 20 psi but it will get kind of close to the red, on top of that it was also makign a wear grinding or smaking sound inside the engine. Wich was a good enough escuse to go ahead and rebuild my engine. Do you guys think it a good idea to change my pistons to the new coated pistons they came up with in 2002 to help with the burning oil and piston slap issue? the car has 46k miles on it. 
Last edited by zamboxl; Apr 23, 2004 at 08:21 AM.