Oil pressure over 100psi
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Oil pressure over 100psi
I've been running with no pressure gauge since I got my swap car running, so I decided to add an Autometer gauge with my heads/cam swap. Hot idle is around 55psi, cruise is around 75psi, and WOT pegs the needle at over 100psi.
Engine is a 2002 5.3 (roughly 125k miles). Oil is 5w30 Pennzoil Platinum with an AC Delco filter. Heads, cam, lifters, chain, oil pump are all new. Its been running for a little over 1000 miles like this with no obvious issues, but I'd like some input for piece of mind. I can't seem to find a thread where anyone has much over 80psi.
Engine is a 2002 5.3 (roughly 125k miles). Oil is 5w30 Pennzoil Platinum with an AC Delco filter. Heads, cam, lifters, chain, oil pump are all new. Its been running for a little over 1000 miles like this with no obvious issues, but I'd like some input for piece of mind. I can't seem to find a thread where anyone has much over 80psi.
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I have seen a few engines run 100psi, it might hurt the filter if you buy cheap ones but should not hurt the engine.
Is the oil warm when it reads 100?
Was the original engine DOD or have the computer controlled cam timing?
Kurt
Is the oil warm when it reads 100?
Was the original engine DOD or have the computer controlled cam timing?
Kurt
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Shouldn't be that high, particularly if you didn't do anything to the motor other than what you described. I would try another gauge (mechanical type) and verify. If it is indeed that high I would change out the pump because the pressure relief valve is sticking if that is really what the oil pressure is.
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Oil reads that high when hot. Engine never had DOD or any of that stuff (2002 LM7).
Pump is a ported LS6 unit from Texas Speed.
I'll see about putting a mechanical gauge on it to verify my pressure.
Pump is a ported LS6 unit from Texas Speed.
I'll see about putting a mechanical gauge on it to verify my pressure.
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Just an update for anyone who cares. I never put a second gauge on it, but its been fine for 5000 very hard miles and 8 passes at the track. Still pegs the gauge at redline. Cold idle is around 75psi, hot idle is 40-50.
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no American engine oil pump should ever go above 70-80 psi because the pressure relief spring in the pump should open. The highest relief pressure is 80 psi, and they range down to around 40 psi but most American v-8's are 70 psi. so either your gauge measuring the pressure is wrong, or the pressure relief valve in the oil pump is not opening or not opening enough. Since you mentioned an aftermarket pump, i would bet something is wrong with the relief valve on it. oil pumps are positive displacement, the faster the engine rpm the more volume of oil it'll pump hence more pressure. aside from the oil filter gasket leaking or letting go, having an oil pump without a pressure relief and over-pressurizing the oil will end up heating up the oil at the pump causing the oil to break down and eventually cause varnish and sludge.
another thing you can do is with the engine oil cold, rev it up in neutral to 2000-3000 rpm. if you're oil pressure goes higher than you normally see it go when the engine and oil is hot then you have something wrong with the relief valve on the oil pump.
another thing you can do is with the engine oil cold, rev it up in neutral to 2000-3000 rpm. if you're oil pressure goes higher than you normally see it go when the engine and oil is hot then you have something wrong with the relief valve on the oil pump.
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I had the same problem with my lpe oil pump. The high pressure spring is not needed for a stock bottom end. Mine came with two springs, a high pressure, and a standard pressure. I had to switch the springs out, and not it has about 80 psi. That ls6 pump is still higher volumn than a standard 5.3 pump. You can notice the difference if you compare them side to side.
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An update: After changing from Peak synthetic 5w30 and PureOne filter to Mobil1 5w30 synthetic with an AC Delco unit, pressure has dropped to 50-75psi under all conditions.