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Unread 02-17-2014, 04:46 PM   #31
JeepNowski
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Somebody explain to me please.......

What exactly is meant by "dummy gauge"? Is it because the 1 wire sensor sends out 2 impulses? "Off and On"-ie; oil pressure and NO oil pressure?

Or is it something else?
One thing I noticed with mine old unit was it either had perfect oil pressure or zero oil pressure or was in between going from one of the two.

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Unread 02-17-2014, 05:23 PM   #32
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Quote:
Originally Posted by JeepNowski View Post
Somebody explain to me please.......

What exactly is meant by "dummy gauge"? Is it because the 1 wire sensor sends out 2 impulses? "Off and On"-ie; oil pressure and NO oil pressure?

Or is it something else?
One thing I noticed with mine old unit was it either had perfect oil pressure or zero oil pressure or was in between going from one of the two.
More or less.

'99-'01 (or '02, I cant remember exactly) got a legit sending unit that gave fluctuating readings depending on oil temp, engine load, etc. The later WJ's got a dummy gauge that just tells you whether or not you have oil pressure. The readings will never fluctuate during the time the engine is running.
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Unread 02-17-2014, 05:44 PM   #33
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^^^Excactly how they Work, the 1 wire "dummy" gauge on 04's only shows if oil pressure are present or not, like an on/off switch.
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Unread 02-17-2014, 05:48 PM   #34
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Ok, that's what I thought. Just wanted to make sure my understanding was correct.
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Unread 02-18-2014, 10:54 AM   #35
poisoness
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Quote:
Originally Posted by Dmbish76 View Post
Hello I am having the same issue as u. Did you Change your sending sensor, did it stop the prob. Please help.
Thank you,
what happens if ypu don't replace it, if it works at 1200 rpms what the problem. it wont stop oil pressur from working. don't you think.
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Unread 02-24-2014, 11:11 AM   #36
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Chalk me up to having this issue as well. It fluctuates, but checked the dipstick and oil looked normal. Anyone have the part number for a 99?
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Unread 02-24-2014, 12:09 PM   #37
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Don't know the part #, but do yourself a favor and get the mopar replacement. I've seen lots and lots of posts about the parts house sensor not working properly or failing prematurely. I got mine from the dealership and paid about $35.

Also double check the connector going into the sensor....1 wire is the dummy gauge, 2 wires is not.
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Unread 02-24-2014, 01:05 PM   #38
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The OEM unit failed first, right? Maybe the OEM units are made better these days?

At least the parts stores will warranty their stuff.
I get about 3 years out of them tops.
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Unread 02-24-2014, 01:16 PM   #39
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Quote:
Originally Posted by JeepNowski
Don't know the part #, but do yourself a favor and get the mopar replacement. I've seen lots and lots of posts about the parts house sensor not working properly or failing prematurely. I got mine from the dealership and paid about $35. Also double check the connector going into the sensor....1 wire is the dummy gauge, 2 wires is not.

Ok $35 isn't bad from the stealership. I'm pretty sure I have an actual gauge as mine is a 99 and it hovered around 20 for a bit then bounced around.

I'll go oem and just forget about it after. Lasted me 155k thus far. Maybe a good thing to change with the next oil changw
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Unread 02-24-2014, 05:08 PM   #40
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My symptoms were when it was cold out side, like below 34 deg. The gauge would drop to zero while driving, but in neutral or park, it would go to normal. After driving for a while (like 50 miles or more) it would work fine again.

I replaced the unit and it has been fine since. I got mine from Rock Auto.com for about $32 including shipping.
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Unread 06-03-2014, 08:12 PM   #41
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I had an oil change a couple weeks ago on my '00 GC (4.0L 6, 151k) and just in the last few days noticed the oil pressure gauge showing higher than normal....around 40-50 at idle and up to 70-80 at freeway speeds. One thing that makes me suspicious is if I turn the key w/ the engine off, the gauge goes up to about 45. Should be at zero if the engine is off and cold, I would think?
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Unread 06-04-2014, 12:35 AM   #42
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Originally Posted by robertwhall View Post
I had an oil change a couple weeks ago on my '00 GC (4.0L 6, 151k) and just in the last few days noticed the oil pressure gauge showing higher than normal....around 40-50 at idle and up to 70-80 at freeway speeds. One thing that makes me suspicious is if I turn the key w/ the engine off, the gauge goes up to about 45. Should be at zero if the engine is off and cold, I would think?
Amazing how these Heeps all have the same Fin' problems. I changed my oil two weeks ago with some cheap non-synthetic oil and wanted to drive on that oil for about couple hundred miles before dumping it and go back to synthetic so I could flush the engine. However, my oil pressure gauge is now reading 80 now when driving around.
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Unread 06-04-2014, 06:06 AM   #43
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To me, it's not the Jeep's problem to have these sensors fail.
It seems making one to spec by the various parts manufacturers is where the problem is.

OEM, aftermarket, they all seem to give about 3 years. Again...it's who warranties them for replacement that gets me to a purchase.
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Unread 06-05-2014, 08:41 AM   #44
poisoness
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Wj filter

Quote:
Originally Posted by DaveRous View Post
I haven't gotten an opportunity to stick a manual gauge on the engine tonight (4.7 V8), but was looking for others experiences when your sending unit goes out.

I'm near 100% sure it's not my pump or major blockage(Although I'm running some seafoam in the crank case now to try and clean it before I drain the oil), since I made it about 50-60 miles home with my issues and had zero engine noises, excessive heat, or other things out of the ordinary. On start up my pressure seemed lower than normal, a shade over 40lbs and as the Jeep warmed up the pressure dropped and the check gages light came on. As I was traveling, any time I was on the gas or over 1200 rpms or so the pressure would rise to tops around 40lbs, which is lower than my normal readings, but still acceptable. When I slow down, as in coast, and come to a stop the gauge slowly drops until it reads around 1lb and the check gages light comes on.
That seemed to be the pattern on the way home, but there were periods when the gauge completely stopped working and read 0-1 for long periods, only to slowly raise up again randomly. Oil looks near perfect and isn't low, but there are about 3000 miles on it and the filter(Full synthetic/mopar filter).

as I said, I'm going to let the cleaner idle in the crank case for a bit, then follow the inspection/clean procedure for the sending unit hole and replace it with a new one. There was a bit of extra condensation on the oil fill cap that I noticed, but I've made a lot of short trips in this cold. There seems to be no coolant missing, and zero smoke coming out of the back regardless of engine speed. Anyway, just looking for any input from people that have dealt with issues like that before. Thanks!
I changed to a fram filter, haven't had a problem in over a year.
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Unread 06-08-2014, 10:56 PM   #45
rrrcecc
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OP, when you're oil pressure dropped did the temperature gauge slowly rise?

im having the same oil pressure problem you had, but when my oil pressure drops my temperature will slowly rise.
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