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Oil pressure drops to zero at idle.

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Old 08-25-2008, 09:16 AM
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Unhappy Oil pressure drops to zero at idle.

Never had this problem before, but I was on my way to Houston last night when my oil pressure started to drop to zero anytime I got off the interstate and the engine would idle. Any ideas other than the obvious (oil pump possibly going bad)? This is in my Jeep, FYI, but I figured that it would be the same concept as in the LS1. Thanks for the help, as I'm supposed to be making a 15 hour drive to Virginia in a few days.
Old 08-25-2008, 09:29 AM
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oil sender could be dying
Old 08-25-2008, 09:32 AM
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Does the valvetrain get noisy like it is starved for oil? If not I would look at the sending unit then gage.
Old 08-25-2008, 09:32 AM
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is it spiking, or just steadily falling when you come to idle? If its spiking then its prob your sender, if its steadily falling its prob your oil pump.
Old 08-25-2008, 09:40 AM
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The valvetrain is not noisy at all, and it is a slow, steady drop; there are no spikes in the pressure either up or down.
Old 08-25-2008, 09:42 AM
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Pull the oil pan and see if the pickup fell off.
Old 08-25-2008, 09:45 AM
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But if the pickup somehow is gone, wouldn't there not be any pressure at all?
Old 08-25-2008, 09:47 AM
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First off i would try hooking up a manual gauge and getting a actual reading, the factory style sender units are known for showing false readings.
Old 08-25-2008, 09:53 AM
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Is that something I could "rent" from AutoZone, and where would I hook that gauge up at?
Old 08-25-2008, 09:56 AM
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Theres a place that you can tap in right above the oil filter.
Old 08-25-2008, 10:01 AM
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Just get a new sender and I bet all will be fine.
Old 08-25-2008, 10:11 AM
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Thanks for the help so far. I'm going to definately check the pressure with another gauge to bypass the sending unit. But let me run this idea by you guys: What if there was crap built up on the pick up screen. At idle, the pump might not have enough suction to overcome the buildup, but as the rpm's go up and the pump pulls harder, it has enough suction to get the oil past any buildup......? Just a thought.
I'm definately hoping its the sending unit. I'll be in Houston until tomorrow. If it looks like I can wait until I get home, then I'll fix it then.
Old 08-25-2008, 10:19 AM
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driving down the road where is the needle on the gauge? Or if the gauge reads pounds how much does it have? Not likely the screen is covered with sludge unless the engine has been abused as far as oil changes. I have only seen one engine in my life that has had the screen plugged with crap and that was an old engine from the 70s
Old 08-25-2008, 11:33 AM
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Ok, I just drove it around for a while and now everything's fine....WTF? The gauge reads right in the middle (can't remember what the psi is) I'm just going to keep an eye on it, and if it starts acting up again, at least I have some ideas on where to start. Thanks guys.
-Marc




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