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Oil pressure falls suddenly?!?!?

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Old Oct 10, 2003 | 02:13 AM
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Default Oil pressure falls suddenly?!?!?

Hey,
A few days ago I was driving and got on it a little...and out of the corner of my eye I saw the oil pressure drop. I let off and the oil pressure went back up to normal for me (roughly 40lbs warm idle). I pulled over and checked the oil...full.

The pressure is consistantly dropping at 1/2 throttle or more from a dead stop. It starts to drop, and Im not sure how low it gets...maybe 20lbs. I havent let it drop any more than that. Under normal (granny) driving the pressure is good still.

At first I thought that somehow I could have lost oil and the oil pump could be running dry, but she's got plenty of oil. So I assumed it was the oil pump failing and made an appointment (with a sponsor) to have it checked out and possibly replaced.

I was under the impression that most of the time when oil pumps fail, my pressure at idle would suffer.

Also idle is sounding a little noisy (lifter noise/piston slap?) at cold idle.

Sound like a bad oil pump to you guys/gals?

Thanks for any input.

-Doug

My car:
98 T/A, auto, Yank Y3000, transgo, Mac headers/ORY, stealth lid, SLP dual/dual, STOCK CAM.
Old Oct 10, 2003 | 02:25 AM
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Default Re: Oil pressure falls suddenly?!?!?

could just be the stupid sender.......

do an oil change as well...make sure there not water in the oil/oil in the water head gasket issues...you're not seeing smoke or anything are you???
might be the oil pump...but usually it shows at idle too...unless it is the gear teeth(which do wear out)...then you might not see it at idle..cause friction is still good enough for slow rmp...but when you gas it...they would start to slip more...and you would see less pressure...
tough one without checking it out further
Old Oct 10, 2003 | 05:07 PM
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Default Re: Oil pressure falls suddenly?!?!?

Head gasket is something I didnt even think of.

But there is no rough idle or oil in the water.

Any more input? I tried a search before posting...and I came up with lots of oil pressure problems, but none like mine.

Please help
Old Jun 1, 2011 | 12:00 AM
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85transamtpi , I would change your oil pump, but I if that doesn't fix it; then I have heard people tapping a fitting into the bock behind the intake, and rigging that up to a real gauge. I'm about to do that. Maybe the fitting, hose, guage, etc, might be cheaper and easier to do, depending on you or course.

A good oil pump to use, in case you didn't know already, is the Melling, high volume and high pressure pump. That's what I'm using and see great numbers.

Let us know how it goes...
Old Jun 1, 2011 | 10:27 AM
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8 year old thread...
Old Jun 1, 2011 | 11:46 AM
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Great job, professor. But believe it or not, there's a search function. And it's used quite a bit. If there wasn't a database of older discussions, then alot of people wouldn't find the info they need. I like to help, especially if I come across something I can be of assistance to, but thanks for your input anyway.
Old Jun 1, 2011 | 11:49 AM
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Look...you asked the OP "Let us know how it goes". I was just letting you know that he wrote this 8 years ago and I seriously doubt he's going to still be working on it. I wasn't being a smart *** in any way.
Old Jun 1, 2011 | 11:53 AM
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It's all good bro, I was just putting my 2 cents out there and maybe he'll see it, maybe he won't. I was just curious if he figured out his problem. Maybe he'll get an email alert and chime in and tell us what happened.
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Old Jun 1, 2011 | 11:56 AM
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I for one am glad you told me it was 8 years old, I was about to start freaking helping out! HA, stumped me!

Well since were helping I think it is the fractionator in the oil pump transfergo going out. What do you think?
Old Jun 2, 2011 | 01:24 AM
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If it were 1 of the j6200 series pumps then yes that's exactly what it would be , but,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,being the old style I would say possibly o-ring issue
Old Jun 2, 2011 | 01:36 AM
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