Oil pressure @ wot 45psi?
Oil pressure @ wot 45psi? I have been trying to figure out what's going on. Just bought the car a month ago and noticed the oil pressure @ wot once warm only made it to mid 40's, @ hot idle was 25psi, car has 35k miles on it. I did cam and heads on it, while I was there I bought a new oil pump from the dealer and dropped the pan. The pan was spotless so installed the new oil pump and now my hot idle oil pressure doesn't go lower than 34psi but wot pressure is still 45psi, any ideas?
I have been trying to figure out what's going on. Just bought the car a month ago and noticed the oil pressure @ wot once warm only made it to mid 40's, @ hot idle was 25psi, car has 35k miles on it. I did cam and heads on it, while I was there I bought a new oil pump from the dealer and dropped the pan. The pan was spotless so installed the new oil pump and now my hot idle oil pressure doesn't go lower than 34psi but wot pressure is still 45psi, any ideas?
A high pressure high volume would have better numbers.
Don't think your O ring is faulty.
O-ring was replaced also, it is a 2012 ctsv so it doesn't have a 9 quart system, only 6 so I didn't want to do a high volume and suck the pan dry. I'm stumped on this and 45 @wot just doesn't seem right, I would expect 55-60
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Teching In
Joined: Mar 2015
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A basis oil pressure guideline rule I previously found read an engine should have 10 lbs pressure for every 1000 RPM's. My LS2 engine and others follow this rule staying within the above parameters. If the engine is not building more oil pressure cam bearing or some other issue exists.
that rule is pretty useless with ls engines. I think gm specs 6 psi at idle is ok. Op as long as the motor has no metal shavings and runs fine then i wouldnt look to much into it.
TECH Regular
Joined: Sep 2013
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A basis oil pressure guideline rule I previously found read an engine should have 10 lbs pressure for every 1000 RPM's. My LS2 engine and others follow this rule staying within the above parameters. If the engine is not building more oil pressure cam bearing or some other issue exists.
http://www.enginebuildermag.com/2015...ight-oil-pump/
I would never run a high performance street/daily type engine with an OEM bearing/style pump, through to any kind of redline with just 45psi of oil pressure, I dont care what application or what displacement. Your spinning 6k or 7k, then I want to see 65+psi of oil pressure on a fully warm engine or I start driving it easy, making plans to go in there and replace that pump or perform a rebuild. You dont keep running it till it burns up- then the block is wasted, as metal flakes start washing out of parts that ran dry briefly after each pass, accumulating in oil passages until those are also blocked further compounding the problem and trashing the engine. I won't rebuild an engine that lost oil pressure and suffered bearing failure because of it because you run a risk of putting it back together with the same debris tucked inside.
I wouldn't worry about 45psi at WOT unless it used to be a lot higher. A higher volume pump would bump the pressure up if it would make you feel better, and unless you're doing some top speed/mile type racing, you won't have a problem with sucking the pan dry. I have the 10296 on my car with a stock F-body pan and never had low oil level/pressure issue with normal "spirited" street driving.
I dont know if this is obvious or not, but the thicker oil you use, the less flow you get at the same pressure. You can wind up using a thicker oil, seeing more pressure on the gauge, and having a drier/dry set of bearings at high rpm because of it. the increased RESISTANCE to flow is what the pressure number is showing you.
The only reason such a low number (45) worries me is because the engine could be losing it somewhere (an internal oil leak), or worse, the oil pump could be about to fail (like someone said, if it used to be higher, this indicates a failure may occur soon). Since we cannot scope the cylinder #1 rod bearing at max RPM it is hard to say whether it is getting lubricated sufficiently or not. To help with diagnosis, you can temporarily use a thicker oil to see if the number improves (just to verify that the oil pressure control check valve is working) When you first cold start it should really be up there near the check valve open point, probably 65-90psi cold. Not at idle, maybe 1500rpm~. Seeing a dead cold engine fire up with an OEM bearing clearance at 1500rpm (DEAD cold) and seeing 45psi of oil pressure would scare the !@)(@ out of me.
The only reason such a low number (45) worries me is because the engine could be losing it somewhere (an internal oil leak), or worse, the oil pump could be about to fail (like someone said, if it used to be higher, this indicates a failure may occur soon). Since we cannot scope the cylinder #1 rod bearing at max RPM it is hard to say whether it is getting lubricated sufficiently or not. To help with diagnosis, you can temporarily use a thicker oil to see if the number improves (just to verify that the oil pressure control check valve is working) When you first cold start it should really be up there near the check valve open point, probably 65-90psi cold. Not at idle, maybe 1500rpm~. Seeing a dead cold engine fire up with an OEM bearing clearance at 1500rpm (DEAD cold) and seeing 45psi of oil pressure would scare the !@)(@ out of me.
TECH Fanatic
Joined: Jul 2007
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From: Wilmington, De
There is absolutely nothing wrong with 25 PSI at idle.
Clearances dictate oil weight.
I dont know if this is obvious or not, but the thicker oil you use, the less flow you get at the same pressure. You can wind up using a thicker oil, seeing more pressure on the gauge, and having a drier/dry set of bearings at high rpm because of it. the increased RESISTANCE to flow is what the pressure number is showing you.
