Oil pressure drops and comes back after restart
#1
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Oil pressure drops and comes back after restart
I have a basically stock engine. I've had an annoying ticking sound since I bought the car 8-9 months ago. In an effort to quiet it, I bought some 15-40 Mobil 1 and some "Miracle Lifter Fixer-Upper" from Autozone. The tick went away for awhile but after a WOT blast at the track, the tick is back louder then ever. Yesterday, my Check Gauges light came on and I noticed the oil pressure at 0. I shut the car off and coasted into a parking lot. I fired the car back up and the oil pressure came back. I drove the car about 20 mins and the oil pressure dropped again. Again, I turned the car off and restarted it and the oil pressure came back. This has now happened 4 times in the past 36 hours. Each time, I've killed the motor almost immediately. There are no new engine noises (aside from my tick being loud ).
Could this be the heavy weight oil not making it through the oil pump like it should?
Could it be the "Miracle Lifter" BS screwing with my gauge?
I have a case of 5w-30 and a new filter to swap in but thought I'd get your opinions. TIA
Could this be the heavy weight oil not making it through the oil pump like it should?
Could it be the "Miracle Lifter" BS screwing with my gauge?
I have a case of 5w-30 and a new filter to swap in but thought I'd get your opinions. TIA
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I ran 0W-40. I also ran a mixture of 0W-40 and 15W-50 for awhile, and it made it through the pump just fine. Until the leak and o-ring got fixed it would on occasion drop below 40 psi on pressure, and other times it wouldn't. I would change the pump and o-ring to be safe.
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If the pump comes off, so will the heads/cam/manifolds. I'm starting to wonder if it's the sending unit for the gauge because turning the car off and back on fixes the problem. Why would the pump stop working with the engine spinning 2,000 rpms and then start working upon start up? That doesn't make sense to me.
#5
Sounds kinda like my problem, only the opposite. Mine has none on startup and after a few minutes I get pressure. After I read on here about the pressure relief valve on 98-2000 sticking open I decided to just replace the pump, just to be safe.
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Originally Posted by Tech
If the pump comes off, so will the heads/cam/manifolds. I'm starting to wonder if it's the sending unit for the gauge because turning the car off and back on fixes the problem. Why would the pump stop working with the engine spinning 2,000 rpms and then start working upon start up? That doesn't make sense to me.
#7
That sending unit problem sounds correct to me. It wouldn't make much sense to me for it to lose all oil pressure then gain it back after restart.
I don't see how, mechanically, it could happen. I could see the oil pump gradually losing pressure output over time, but the fact is, the oil pump is should still be getting spun by the crank.
Of course, you could be sucking a large object over your pickup tube, but I don't see that as likely either.
I don't see how, mechanically, it could happen. I could see the oil pump gradually losing pressure output over time, but the fact is, the oil pump is should still be getting spun by the crank.
Of course, you could be sucking a large object over your pickup tube, but I don't see that as likely either.
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#8
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If the ticking is louder, this started after a WOT run, you changed the oil and added the junk because of ticking, I think all of your evidence points to a problem with the pump, not the sending unit. I wouldn't fool around with it - change the pump and throw a cam in there while you're at it!
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The checkbook doesn't have room for a cam right now. The car still has stock manifolds on it.
I suppose I'll buy the $60 LS1 oil pump and a new timing chain. Damn shame to tear it down that far and not put a cam in it.
I suppose I'll buy the $60 LS1 oil pump and a new timing chain. Damn shame to tear it down that far and not put a cam in it.
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Along with a cam comes... springs, retainers, shims, lifters, ported heads (already have stockers to have ported), headers and a ton of misc crap. My $250 repair turns into a $1500 repair.