Oil pressure drops at high rpm
11-02-2011, 08:38 PM
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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.
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.
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.
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?
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?
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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.
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.
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?
Any ideas?
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.
