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Old 02-19-2007, 04:12 PM   #1
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Default LOW oil pressure

Well ever since I had the UIM and LIM done, I have had pretty low oil pressure. It starts out just over the 40 mark, but after driving a while it drops. It get * to the point that at an idle it is as close to be in the red as it can be without going in. I assume this is bad. Not sure how to fix it.
Weather is so cold haven't had much of a chance to check it out.
Any thoughts?
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Old 02-19-2007, 04:49 PM   #2
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Start off by hooking up a mechanical guage. That will point you in the right direction on whether or not you have an internal engine problem, faulty guage on the cluster, or bad oil pressure sending unit.
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Old 02-19-2007, 05:00 PM   #3
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Quote:
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Call me stupid, but I can't afford to be....
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......mechanical guage....
What'* that?
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Old 02-19-2007, 05:30 PM   #4
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A mechanical gauge measures oil pressure by connecting a tube fitting to some part of the oil gallery. The oil pressure is read directly by the gauge without electricity. You can buy one at a parts house for $10-$20.
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Old 02-19-2007, 05:35 PM   #5
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So, you remove the oil pressure sensor from the engine and install the mechanical version. After the car starts, won't the PCM shut the car off because it sees ZERO pressure? Or will it just keep running?
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Old 02-19-2007, 05:36 PM   #6
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Did your UIM fail?


If the oil pressure is indeed around 10PSI or so I'd point my premature superduper diagnosing finger at main bearings. then again the spring in your sender could be DOA and it could just be a faulty sender all together.

sender units are cheap but mechanical oil presure gauges are cheaper.
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Old 02-19-2007, 05:45 PM   #7
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Yeah. UIM failure. The white smoke out of the exhaust was kinda cool, like a smoke screen form a video game. Remember old school Spy Hunter? I think that was NES. Anyway, yeah just had the UIM done like a month ago.
I'll have to look into one of the mechanical gauges.
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Old 02-19-2007, 07:25 PM   #8
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So....after the car cooled down from my wife getting home I checked and it was a quart low. So I am going to go get some in a few. Just another thought. When the guy did my UIM he also did an oil change. What if he used cheap oil or not the right weight? Could that have an effect? What should I be using as far as weight? I have always used Pennzoil, as had the previous owner.
And, oh yeah...how bad is it to run it right now. The pressure is fine when I am driving, it only gets low when idling. Keep in my that this ONLY happens after it has been running for a while and then ONLY when idling.
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Old 02-19-2007, 07:44 PM   #9
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A probable scenario is that coolant from the failed UIM got mixed in with the oil and circulated through the oil system eroding the bearings. You can increase the oil pressure and get a little better protection with worn bearings by using a heavier weight oil. I am running Shell Rotella T 15W-40 in mine with no problems. This will increase the pressure significantly compared to 5W-30.

On hooking up the mechanical gauge, you can use a tee fitting so that the mechanical gauge and the sender can be connected at the same time.
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Old 02-19-2007, 07:48 PM   #10
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as bill mentioned running a thicker oil may make the motor last longer if we indeed have an oil pressure problem to begin with.
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