Oil Pressure Issue Need Ideas
05-19-2018, 05:59 PM
#1
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Oil Pressure Issue Need Ideas I have just recently finished doing a top end build on a LS1. I installed a melling high flow pump while I was doing everything else. I was breaking in the engine, and the oil pressure was hold between 40-60 for about 30 minutes, dropped to 20 for about 15 minutes, then after accelerating onto the expressway I had no oil pressure and a joyous tapping sound. I started it today to move it to the garage, tapping sound is gone, the pressure was 60 again, it was idling rough and wanting to die, and the oil has a bad fuel smell. I am figuring I have a bad injector, and probably need to check the oil seal. What else do I need to look into.
Mods:
TSP 228R cam
Stage 2.5 PRC heads
Melling High Flow pump
Stock Intake
Stock injectors
Stock Lifters
Mods:
TSP 228R cam
Stage 2.5 PRC heads
Melling High Flow pump
Stock Intake
Stock injectors
Stock Lifters
05-19-2018, 06:27 PM
#2
TECH Senior Member
I'm wondering if the pressure relief valve in the pump hung up for a bit before "unhanging" up and returning pressure to normal. Just a theory....
05-19-2018, 07:02 PM
#3
ModSquad
iTrader: (6)
Did you get the car tuned after mods? Fuel in the oil means she’s pig rich. Get that oil out of it, and schedule a tune, if you haven’t already done so. Your plugs are probably fouled, which is why it ran rough today.
05-19-2018, 08:33 PM
#5
That's my guess too. The fuel smell doesn't mean much unless the oil is diluted with fuel. All engine oil especially a performance engine like these are going to have a heavy fuel smell to the oil.
05-20-2018, 10:26 AM
#7
TECH Senior Member
I have to agree with this. High volume pumps are usually advised against, not so much for pumping the pan dry, but for pumping more oil than the system can handle. Too much ends up being bypassed at the pump.
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05-20-2018, 11:27 AM
#8
TECH Addict
Pretty sure this is what killed the motor in my last car. oil pressure would peg the gauge right up until about 5k or so and fall off. as soon as i would lift it would come back up. didn't matter how hard i would beat on it in the mid range only ever happened up top. if i remember right i was running the melling high volume pump with the high pressure spring. it was definitely over kill.
05-20-2018, 11:42 AM
#9
TECH Addict
Also i just remember something, engine masters has an episode where they tested oil pans and oil level on a solid roller bbc. one pan was stock truck style with out a windage tray, with the oil at factory level they were getting air in the oil and loosing psi. after dropping oil level it picked up something like 20 hp and no dip in psi. then they tested a milodon high volume pan with a windage tray. with the oil at recommended level they were still getting air in the oil and loss in psi/hp. they had to drain about 3 qts before it stopped and they gained the power and pressure back. so i'm curious if anybody has ever data logged an ls motor in the same way? at what point does the oil start to foam up? is factory recommended level ok, too low or too high?
05-20-2018, 12:59 PM
#10
ModSquad
iTrader: (6)
I disagree. Oil should never smell like fuel. If it does, you have tuning issues.
05-20-2018, 01:55 PM
#11
Not true, you're telling me NONE of your daily driver cars has fuel smell from the used motor oil that's constantly being hit by at least 10% or more combustion gases. Where do you think these gases go? Right into the oil! I've NEVER checked oil on any engine that didn't have some fuel smell after being shut down hot. ITs impossible!
Like said above as long as it not diluted with raw fuel its normal, ALL engines have blowby<now tell me that's not true.
Like said above as long as it not diluted with raw fuel its normal, ALL engines have blowby<now tell me that's not true.
05-20-2018, 02:59 PM
#12
TECH Senior Member
I agree with this. The only time I commonly smelled gas in the oil was on carbureted cars that never fully warmed up or were not run hard enough to evaporate the gas out of the oil. Never smelled it on a properly running EFI car.
05-20-2018, 03:16 PM
#13
ModSquad
iTrader: (6)
[QUOTE=RockinWs6;19899873]Not true, you're telling me NONE of your daily driver cars has fuel smell from the used motor oil that's constantly being hit by at least 10% or more combustion gases. Where do you think these gases go? Right into the oil! I've NEVER checked oil on any engine that didn't have some fuel smell after being shut down hot. ITs impossible!
Like said above as long as it not diluted with raw fuel its normal, ALL engines have blowby<now tell me that's not true.[/QUOTE
NONE of my daily’s have fuel smell in the oil, and trust me, I smell the dipstick every time I pull it.
Blowby from combustion, yes that’s true. No such thing as perfect ring seal, even with a vac pump. Fuel blowby from too much fuel in the chamber is different, and means you have tuning issues. That’s what makes the oil smell like gas. Your oil should never smell like gas.
Like said above as long as it not diluted with raw fuel its normal, ALL engines have blowby<now tell me that's not true.[/QUOTE
NONE of my daily’s have fuel smell in the oil, and trust me, I smell the dipstick every time I pull it.
Blowby from combustion, yes that’s true. No such thing as perfect ring seal, even with a vac pump. Fuel blowby from too much fuel in the chamber is different, and means you have tuning issues. That’s what makes the oil smell like gas. Your oil should never smell like gas.
05-20-2018, 03:35 PM
#14
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I have better results overfilling the LS by a quart. I remember that used to be the thing -- better to be two quarts low vs 1/2 quart high. But I seen too many LS have better pressure overfilled vs filled at spec.
05-20-2018, 03:41 PM
#15
TECH Senior Member
I would speculate that the stock pump pulls the level down far enough in common usage that even overfull by a quart does not cause it to get whipped up. I am sure the windage tray helps in that regard also.
05-20-2018, 06:15 PM
#16
TECH Addict
05-20-2018, 06:59 PM
#17
TECH Senior Member
That WOULD be an interesting experiment!
05-20-2018, 07:42 PM
#18
[QUOTE=Che70velle;19899901] So what you're saying is YOUR BLOWBY DOESN'T STINK LMAO
Not true, you're telling me NONE of your daily driver cars has fuel smell from the used motor oil that's constantly being hit by at least 10% or more combustion gases. Where do you think these gases go? Right into the oil! I've NEVER checked oil on any engine that didn't have some fuel smell after being shut down hot. ITs impossible!
Like said above as long as it not diluted with raw fuel its normal, ALL engines have blowby<now tell me that's not true.[/QUOTE
NONE of my daily’s have fuel smell in the oil, and trust me, I smell the dipstick every time I pull it.
Blowby from combustion, yes that’s true. No such thing as perfect ring seal, even with a vac pump. Fuel blowby from too much fuel in the chamber is different, and means you have tuning issues. That’s what makes the oil smell like gas. Your oil should never smell like gas.
Like said above as long as it not diluted with raw fuel its normal, ALL engines have blowby<now tell me that's not true.[/QUOTE
NONE of my daily’s have fuel smell in the oil, and trust me, I smell the dipstick every time I pull it.
Blowby from combustion, yes that’s true. No such thing as perfect ring seal, even with a vac pump. Fuel blowby from too much fuel in the chamber is different, and means you have tuning issues. That’s what makes the oil smell like gas. Your oil should never smell like gas.