Oil Pressure

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gherron

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Took my 2004 Jeep Wrangler to town for service. Shortly after when coming to a stop and idling oil pressure would drop to zero setting off alarm and check guages warning. Bringing rpm's up and or taking off pressure is back to normal. Had diagnostics run and no error code shows up. Anyone else had this problem?
 

Dsth

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My first question would be what kind of code reader the service center uses. some smaller shops have code readers that only display active codes. dealers and larger service centers generally have more sophisticated readers that will also read previously active codes. difference being a couple thousand dollars in cost sometimes. When you say in for service, does that imply an oil change? If so, my first thought would be a lower viscosity oil was used to refill. How many miles does your 2004 jeep have on it? Vehicles naturally pump less oil at lower RPMs and as they get older with more miles, the oil pump gets to the point that it can not pump enough oil at idle to maintain pressure. even a different brand of oil filter is enough to cause this problem in older engines. do you often look at your oil pressure at a stop sign or just now that the "check gauges" light came on? this may have been a gradual drop without you noticing until now. It could also be a simple thing as oil pressure sensor going bad. hope it is a simple fix and good luck.
 

callmefence

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Took my 2004 Jeep Wrangler to town for service. Shortly after when coming to a stop and idling oil pressure would drop to zero setting off alarm and check guages warning. Bringing rpm's up and or taking off pressure is back to normal. Had diagnostics run and no error code shows up. Anyone else had this problem?
First thing is stop driving it.
Newer vehicles set codes for lights being out and other mundane things.
Older vehicles it's just engine, tranny items monitored and controlled by ECM. Oil pressure not being one of them. So no code means nothing.
Could be a bad sensor, or worn bearing inserts, etc, etc. You need to remove sensor and use a manual oil pressure gauge to determine if your problem is mechanical or not.
 

Silver

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When you say it drops to zero I assume that means it has an oil pressure gauge? Does it run rough or rattle at an idle?
Agree with above, stop driving it until you know what the deal is. And check the oil level. Is it possible they under filled it?
 

D2Cat

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Took my 2004 Jeep Wrangler to town for service. Shortly after when coming to a stop and idling oil pressure would drop to zero setting off alarm and check guages warning. Bringing rpm's up and or taking off pressure is back to normal. Had diagnostics run and no error code shows up. Anyone else had this problem?
Did you confirm the service dept did in fact put the oil plug back in? If this situation has not happened before the service I'd be inspecting what/how they did their work.
 

Rydero

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Confirm they used the right viscosity oil. At one time I had a late 90's Dodge truck do something similar when I knowingly topped up witn a couple liters of the wrong oil because it was low. Scared the crap out of me, I changed the oil to the right stuff and it was all good. Most vehicles now the oil pressure gauge isn't really real it's basically an oil pressure light made to look like a gauge for looks so your actual oil pressure may not be running as low as indicated.

Obviously check level and for leaks.
 
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gherron

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Definitely stopped driving it. Several good suggestions, Jeep has 155K miles and this change went with full synthetic oil. Also flushed radiator and front and rear differentials. No idling rough or rattling and as for the code reader small hand held type.
 

Lee VanRoss

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What did the dipstick show? I assume you have the problem diagnosed by this time........................
 

littletom

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My wife had yukon throwing a fit about 10 miles from dealership. Low oil low pressure told her to pull over turm off i was on way. Crawl under it oil running out. They put oil filter on maybe turned it half turn. Oil running out all around filter. They said bring it back we will tighten up. We have not been back a dealership that can't change oil is useless. That deal cost them several sales that was about 3-4 rides ago.
 

D2Cat

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I had a similar situation happen a few years back driving my Dodge diesel to Ft. Collins, Co. Was going north and east of I-25 enjoying the mountain and country view. Come into a small town and hit a traffic light and noticed the oil light on. Made me nervous because I had my niece with me and didn't want any reports to her mother about troubles. There was no "additional" rattling from the engine. I pulled over and waited a bit and checked the oil. Everything seemed fine. Started up and the light was not on. This happened when the engine slowed up at a light and did it several times.

Ended up changing out the sending unit. What's amazing is the oil pressure registered higher with the new unit. Still running it to this day.
 

Dsth

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Definitely stopped driving it. Several good suggestions, Jeep has 155K miles and this change went with full synthetic oil. Also flushed radiator and front and rear differentials. No idling rough or rattling and as for the code reader small hand held type.
hopefully it is an easy fix like D2Cat posted. I suspect the change from conventional oil (CO) to synthetic oil (SO) is contributing to your problem. I recommend that owners should decide when the vehicle is new whether they want CO or SO and not change after the first oil change. your 2004 jeep most likely came with CO from the factory. CO and SO have completely different chemical makeups and an engine that has had CO in it for a period of time builds up a thin layer of lubricant on the internal moving parts of the engine. a film too small to see with the naked eye, but it is there. the chemicals used to make SO dissolves that oil film; therefore increasing the clearance between the moving parts. we are talking about .001s of an inch of clearance for bearing clearances. Combine the extra clearance with the easier flow ability of SO and you have problems like you mentioned. Changing the sending unit would be the first thing to try. If that is not the problem, it will probably be an expensive fix if you plan to drive for another 155K. if you want to just drive until the end, you could drain and refill with a higher viscosity oil to help the low RPM oil pressure. although it is not recommended, you could switch back to CO and see how your pressures look. certainly it could be a completely different cause so please keep us posted.
 

simme

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My wife had yukon throwing a fit about 10 miles from dealership. Low oil low pressure told her to pull over turm off i was on way. Crawl under it oil running out. They put oil filter on maybe turned it half turn. Oil running out all around filter. They said bring it back we will tighten up. We have not been back a dealership that can't change oil is useless. That deal cost them several sales that was about 3-4 rides ago.
I know many people who have had their oil changed and the oil plug not tightened, or the oil plug stripped or the filter not tightened. Then later notice an oil leak or worse the oil light comes on. Even at a dealer, they probably don't put their most experienced person on the oil changes. That is why I do all the oil changes in my vehicles myself.
 

Caustic Burno

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See if they changed types of oil filter.
More likely to have oil problems with today’s engines if they put conventional oil in them.
Synthetic oil is hydrocarbons just like conventional.
The synthetic part is it has been molecularly changed to all the molecules are the same size. This allows for tighter tolerance. Conventional motor oils consist of wide span of carbon molecules.
The conventional oils can not pass through the tighter tolerance.
 

Stocker Steve

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Ended up changing out the sending unit. What's amazing is the oil pressure registered higher with the new unit. Still running it to this day.
Me too. New sender is 15 psi higher. Sender and pickup tube O ring are common failures on Chev.

If you have oil in it, and there is not any noise, you can down shift to clear the alarm and limp it home.
 

alacowman1

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Took my 2004 Jeep Wrangler to town for service. Shortly after when coming to a stop and idling oil pressure would drop to zero setting off alarm and check guages warning. Bringing rpm's up and or taking off pressure is back to normal. Had diagnostics run and no error code shows up. Anyone else had this problem?
Walmart service center?
 

Stonewall Joe

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Took my 2004 Jeep Wrangler to town for service. Shortly after when coming to a stop and idling oil pressure would drop to zero setting off alarm and check guages warning. Bringing rpm's up and or taking off pressure is back to normal. Had diagnostics run and no error code shows up. Anyone else had this problem?
could be a faulty oil sending unit
 
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gherron

gherron

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All good advice. Since oil level is good mechanic suggested changing the sensor/sending unit first. However, I'm going to drain and go back with the CO and another filter first to see if that remedies the problem. Thanks all and I will keep you posted
 
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