Low idle oil pressure?

CyFi6

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Oct 11, 2007
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Ive got a 7mge with 80k miles on it, and when its idleing at around 700 rpm the oil pressure can get to as low as 2-3psi sometimes, but as soon as i start moving the pressure seems pretty normal. At 3k rpm it usually wont go any lower that 50psi when fully warm. Is this caused by a pressure relief spring or is it an engine bearing problem most likely? THanks.

By the way, i am running a napa gold filter with 10w-40 castrol oil right now. I am using a prosport oil pressure gauge. I have had a problem with this gauge previously where it actually read 0 psi, and i had the sender warrentied, not sure if this one is also acting up or what, the problem is if i just let the car idle to warm up the oil pressure never gets to full temperature, so i cant use a mechanical gauge to figure out my lowest pressure, its after ive been driving around town or on the highway that my pressure gets its lowest and i cant have the mechanical gauge hooked up while i go cruising around.
 
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jetjock

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Jul 11, 2005
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I don't quite understand what you're getting at. Are you questioning the gage? If so you can always tee in a mech gage and use both. Relocate the port with a hose if you have to or use another, say the one near the power steering pump. There's also nothing stopping you from checking the Prosport with an air regulator. That said your oil pressure doesn't seem all that bad other than it's high when cruising. I'd lose the 10-40.
 

CyFi6

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well thats not exactly what im getting at. What im really worried is my oil pressure at idle, spec is at LEAST 4psi and im getting less than that at times. I knew the first comment would be to verify the reading with a mechanical gauge so i posted the reasons why i could not do that.

Also, you mentioned that i could relocate the port with a hose. I was really interested in doing this but i cannot find all the correct fittings i need in stock on summit racing and i was wondering if you guys could help me find what i need. I am new with all the an fittings and such. Another thing i feel is that the gauge sender is getting too hot from being next to the exhaust manifold which is why i wanted to relocate it also.

Also, how do i test the gauge with an air regulator? What kind of fittings would i need? THanks.
 

CyFi6

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The times my pressure drops even more than 2 psi is after i have ust done a high rpm/full throttle pull for a little bit. Im afraid to put an oil rated less than xw-40 in fear my idle pressure will drop even more
 

AJ'S 88NA

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Jul 26, 2007
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I'd try 5-50w and see were the pressure is. With 80k miles things maybe wearing out a little. If that doesn't help then you might be looking at a rebuild to get the pressure up. Is it a rebuild 80k ago? Was the oil pump replaced at that time?

50 lbs at 3k is pretty good pressure.
 

cuel

Supramania Contributor
Jan 8, 2007
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Read here for oil: Lubricants

Running a thinner oil should bring your operating(3k rpm's) down, but it will also drop you idle pressure as well.
A cheap(read FRAM) oil filter will cause some odd pressure problems. If you're using one, switch to a Wix, or PureOne. Oil Filters

Edit: I see your using a Napa Gold. It's listed in the filter link as well, I believe.
 

626na

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Jan 15, 2008
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i just put on a mobile 1 are they any good..?
it was huge compared to the other ones i looked at..
 

CyFi6

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cuel;900340 said:
Read here for oil: Lubricants

Running a thinner oil should bring your operating(3k rpm's) down, but it will also drop you idle pressure as well.
A cheap(read FRAM) oil filter will cause some odd pressure problems. If you're using one, switch to a Wix, or PureOne. Oil Filters

Edit: I see your using a Napa Gold. It's listed in the filter link as well, I believe.

what should i be looking for in the oil section?
 

suprarx7nut

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Nov 10, 2006
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I would double check your gauge's reading. Plug in another gauge, get it tested with a mechanical one at a shop or something, but be sure the low pressure isn't just a slightly off gauge. I've heard plenty of the prosport gauges being just a tad off esp. with pressure.

If your normal operating pressures are fine I don't really think you have too much to worry about. If a bearing goes, you'll know it if you're paying attention to your motor.

If I were you I'd save for a rebuild in the future and address the problem IF it rears its ugly head. :)


******Edit

I've been reading about oils for a little more than 2 hours now, actually creeping up on 3. :) I figured this statement might relate to your situation. Mine as well, actually. I have a very low idle oil pressure once the engine is warm. But I get 25-40psi while cruising at 60-75 mph.

direct quote from Dr. Haas:
Dr. Haas said:
Some people have tried this and occasionally get a somewhat low oil pressure while at idle. This is fine. There is no stress on parts at idle, the smallest oil flow will do the trick. It is at higher RPM where more BHP is produced. This is where we need the flow. Remember that Ferrari uses 75 PSI at 6,000 RPM as the place to test your oil viscosity needs. If your oil gives this value under your driving conditions then your lubrication system has been maximized. Period.
 
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