Oil Pressure

ufatbasted

Member
Joined
Oct 30, 2021
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27
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NYC
This is my oil pressure at idle.

Jeep runs and sounds fine.

What is normal oil pressure for a TJ 6CYL?
 
Jeep runs and sounds fine.
I don't think your picture posted but generally if this is true you don't need to go into panic mode. Get a mechanical gauge and hook it up to see what you have at idle. Post the general numbers and I'm sure you'll get some feedback. Don't worry too much about what the factory gauges say if it sounds normal (if that's what you tried to post).
 
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oops!

IMG_1815.jpeg
 
Gauges generally pointing up and no "check gauges" light, I'd say you're good to go. What weight oil are you running, what are the temperatures where you are like?
 
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No worries there. That’s the normal range for a factory gauge that isn’t known to be highly accurate.
 
I don't think your picture posted but generally if this is true you don't need to go into panic mode. Get a mechanical gauge and hook it up to see what you have at idle. Post the general numbers and I'm sure you'll get some feedback. Don't worry too much about what the factory gauges say if it sounds normal (if that's what you tried to post).

For the first 4-5 months with 2psi at highway speeds and around town, mine was silent before it made noises! So quietness may not always mean it is good. However, that was after my hydro-lock that you commented on, so as long as the OP did not have fun in the water I agree he should be okay!
 
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For the first 4-5 months with 2psi at highway speeds and around town, mine was silent before it made noises! So quietness may not always mean it is good. However, that was after my hydro-lock that you commented on, so as long as the OP did not have fun in the water I agree he should be okay!
This has come up a few times recently. If you are talking about normal wear and the bearings getting loose, who cares if you catch it early? You're rebuilding anyway. If you are talking catastrophic failure of some kind it will be obvious. I just can't see some in-between situation where catching it early would do any good at all. If you have coolant in the oil, water in the oil, by the time the gauge reads low the engine is gone. What good is an early warning other than time to find a rebuild?
 
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I can never keep track of the years, I let the engine generally tell me how it's doing by the noise and figure the cluster will light up if there's a problem.

I can’t either. I know mine has a “real” gauge as a 2000, I was guessing that they probably changed it when they switched from ccd to pci.
 
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My 2002 is as real of a gauge as it gets. FWIW I'm not convinced that any of the years are dummy. It has been spoken about a bunch, but not proven as far as I can find.
 
Gauges generally pointing up and no "check gauges" light, I'd say you're good to go. What weight oil are you running, what are the temperatures where you are like?

10 w 30. It's been in the high 70's here. When I accelerate it moves up towards 80PSI. That's what caught my eye I don't think the needle ever moved much before.
 
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My 2002 is as real of a gauge as it gets. FWIW I'm not convinced that any of the years are dummy. It has been spoken about a bunch, but not proven as far as I can find.

The ones with numbers are "real."

The ones with L and H are just dummies with a switch instead of a sending unit. Idiot light masquerading as a gauge. If you read the FSM for an 06 it tells you exactly how it works. Switch closes at 6 PSI, PCM moves needle to mid range of gauge. So you know you have 6 PSI, that's it.
 
10 w 30. It's been in the high 70's here. When I accelerate it moves up towards 80PSI. That's what caught my eye I don't think the needle ever moved much before.

That's pretty high. Have you replaced the oil pump? I'd bet you have a high volume or high pressure oil pump. If so, it shouldn't be a problem unless you're running in the upper limits of the RPM range.
 
The ones with numbers are "real."

The ones with L and H are just dummies with a switch instead of a sending unit. Idiot light masquerading as a gauge. If you read the FSM for an 06 it tells you exactly how it works. Switch closes at 6 PSI, PCM moves needle to mid range of gauge. So you know you have 6 PSI, that's it.

Ah I see. A quick check of the part numbers confirms there is a difference. The older 2002 sensor is a 3 wire and reports pressure while the newer 2006 sensor is a 1 wire and only controls a light circuit. Interesting, I learned something new.
 
Ah I see. A quick check of the part numbers confirms there is a difference. The older 2002 sensor is a 3 wire and reports pressure while the newer 2006 sensor is a 1 wire and only controls a light circuit. Interesting, I learned something new.

I'm fairly confident that up through '04 used the three wire setup with a variable resistance sensor. '05 and '06 got the 1 wire setup with a simple "go/no go" pressure switch.

However, in any TJ the sensors for the dash gauges actually send their signals directly to the PCM, which then positions the gauge needles where it has been programmed to do so. This is probably the case for any vehicle sold in the US since the advent of OBDii in '96.

Most reports on various Jeep forums suggest that earlier TJs had much more realistic programming for the oil pressure gauges, so that they could be thought of as a real gauge. Somewhere along the way ('02, '03?) the programming was dumbed down so that if minimum safe pressure is present, the needle is always pointed a hair right of center and never varies.

Ironically, this bogus programming may have been tweaked a little for '05 and '06. I have read where some '05 and '06 owners reported oil pressure gauge needles rising and falling with engine rpm, which can only be from the PCM being programmed to move the needle a little corresponding to rpm.
 
I'm fairly confident that up through '04 used the three wire setup with a variable resistance sensor. '05 and '06 got the 1 wire setup with a simple "go/no go" pressure switch.

However, in any TJ the sensors for the dash gauges actually send their signals directly to the PCM, which then positions the gauge needles where it has been programmed to do so. This is probably the case for any vehicle sold in the US since the advent of OBDii in '96.

Most reports on various Jeep forums suggest that earlier TJs had much more realistic programming for the oil pressure gauges, so that they could be thought of as a real gauge. Somewhere along the way ('02, '03?) the programming was dumbed down so that if minimum safe pressure is present, the needle is always pointed a hair right of center and never varies.

Ironically, this bogus programming may have been tweaked a little for '05 and '06. I have read where some '05 and '06 owners reported oil pressure gauge needles rising and falling with engine rpm, which can only be from the PCM being programmed to move the needle a little corresponding to rpm.

I can confirm the 06 PCM moves the needle around slightly in the mid range to make it appear it is a real gauge.