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Oil pressure drops at high rpm

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Old 11-02-2011 | 08:38 PM
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Default Oil pressure drops at high rpm

So my cars oil pump pressure relief valve stuck open and I lost oil pressure. I imediately turned it off, towed it home. I put a TSP ported oil pump in it, oil pressure is pretty much normal, its anywhere between 40 and 60 driving and 20 to 25 idling.

Now when I floor it and it gets into the upper rpms, say 4000 and above, the pressure suddenly drops then comes back up.

Now I no your thinking I pinched the o ring, I am 99% sure I didnt as I put lucas oil on it and the pickup tube pretty much slid right into the oil pump.

Any ideas? It does this right after I change the oil also with 5.5 quarts of mobil 1.
Old 11-02-2011 | 09:36 PM
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Cut open the filter.. Sounds like a cam or main bearing.
Old 11-02-2011 | 10:36 PM
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Add more oil you're suckin the pan dry
Old 11-03-2011 | 07:30 AM
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Originally Posted by O2Form
Add more oil you're suckin the pan dry
+1 had that happen before
Old 11-03-2011 | 09:28 AM
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Sounds like a thrust bearing. Check your crank endplay. Tell-tale signs are pressure drop under load/rpms. I had a thrust bearing failure and the oil pressure gauge was my indicator something was wrong.
Old 11-03-2011 | 09:32 AM
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Look for .004-.008 of endplay. I had .040, 5-10 times the acceptable limit.
Old 11-03-2011 | 07:27 PM
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Thanks for the replies. I checked the oil this morning, it was in the hatch and full. I put another quart in it anyways. I tested it on the way to work, it doesnt drop all the time, if it does drop it only goes down to from 50 to 40 psi, so its alot better now.

Is the oil pressure supposed to drop at all upon acceleration?

The only thing is my oil change light came on then went off. What makes this light go on?
Old 11-03-2011 | 08:06 PM
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no usually oil pressure goes uo with WOT. So how many quarts do you have in it now.
Old 11-03-2011 | 08:18 PM
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It probably has 6, it was probably a half quart low. It uses a quart every thousand or so. I do beat on it quite a bit when I find not alot of cars around.
Old 11-03-2011 | 08:27 PM
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Your user name is retarded
Old 11-03-2011 | 08:32 PM
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Good one, LOL, actually my name is from back in the day when I had a 98ss, now I have a 99 Z28.
Old 11-03-2011 | 10:20 PM
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Was the idle and driving pressure hot or cold? I lost a main bearing once and it would have 40 PSI idle/50PSI driving cold and 7 PSI idle/20PSI driving hot! But I would think you would be able to hear it knocking if that were the case.

Last edited by bearsoldier17; 11-03-2011 at 10:26 PM.
Old 11-03-2011 | 11:16 PM
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Originally Posted by SWEET98SS

Is the oil pressure supposed to drop at all upon acceleration?
You don't listen too well my friend. Good luck to ya
Old 11-04-2011 | 06:09 AM
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Idling and driving pressure was hot.
Old 11-04-2011 | 06:51 PM
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Ok, so today I was messing around to figure out exactly when the pressure drops, if I ease into the throttle and get up to 6600 rpm, the oil holds at 50 or so psi. But if I am at 4500 and floor it up to 6600, it starts going down once it gets into the higher rpms.

Any ideas?
Old 11-05-2011 | 09:54 AM
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I woood install a manual guage to actually see whats going on. The factory gauge could be wrong.
Old 11-05-2011 | 11:50 AM
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Originally Posted by O2Form
Add more oil you're suckin the pan dry
Didn't you say adding oil helped a lot? Your ported pump is sucking it dry.
Old 11-05-2011 | 12:14 PM
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Yep, instead of it dropping all the time when it gets into the higher rpms, it only does it sometimes and also it only drops to 40 psi instead of the 20 psi. I think i need to give TSP a shout.
Old 11-05-2011 | 08:13 PM
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id get rid of the ported oil pump
all they do is pump the pans dry.
Old 11-06-2011 | 06:08 AM
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I thinking that may be the solution, but go to which pump?


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