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Can anyone here share what their typical oil pressure readings are. Mine run about 30 psi and have even seen it as low as about 26. Is this normal? Seems kinda low to me..
Oil Pressure Readings???????
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My C7 runs in the same range. I had it checked out by a Chevy dealer and they said it is not a problem.
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OK, just took delivery Saturday 5/24. Drove car 100 miles today. (Z51 dry sump)
Idle Oil pressure is 28 psig at idle, 35 psig at 1500rpm, 38psig at 2,000. This seems very low. My LS7 dry sump maintains 50psig hot, drops off to maybe 45 psig at idle.
All temperatures are higher, transmission (not an issue in my ZO6) is 220 and oil runs about 205 on 80 degree day. (ZO6 oil is about 160-165).
Dealer says "normal". Is it?
Idle Oil pressure is 28 psig at idle, 35 psig at 1500rpm, 38psig at 2,000. This seems very low. My LS7 dry sump maintains 50psig hot, drops off to maybe 45 psig at idle.
All temperatures are higher, transmission (not an issue in my ZO6) is 220 and oil runs about 205 on 80 degree day. (ZO6 oil is about 160-165).
Dealer says "normal". Is it?
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Yes, that is perfectly normal. My 2014 5.7L Silverado (same engine architecture) runs in the same range. It's the difference in oil galleys and sensor pickup point that makes it so different than what you are used to.
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Thank you, lots of new stuff to get used to.
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they can make the engines more efficient by running lower oil pressures with higher output pumps. NASCAR engine builders have been doing this for years, scavenging horsepower, and increasing longevity. I think it's about time the manufacturers caught up with some of the race tech.
C7 Oil Pressure Fluctuations - Why? Is this Normal?
I have another issue - oil pressure fluctuation, Z-51, Dry Sump:
When the car is warming up, after driving a mile or two, I get a momentary rise in oil pressure of up to 15 psi AFTER shifting into the next higher gear. I might go to 2000-2500 rpm in first (at normal acceleration levels, in other traffic), then I shift into second, and right after the clutch engages the oil pressure surges from a few pounds to perhaps over 15 psi (as high as 60 psi a few times) and then drops back down to normal, which is between 35-45 psi at normal lower engine RPM's. Same with the next upshift. It barely does it, if at all, after ten or fifteen miles of driving.
It will do this after driving 15 miles (oil temp rising, maybe at 150-160 degrees), if I park to buy a few items in a store, then come back out and start up again.
The oil level is normal, so the oil shouldn't foam.
The voltage barely fluctuates, if at all, while shifting. Some slight voltage fluctuation is usually present.
I have not been able to make this happen by playing with the throttle, but I haven't tried that hard.
Anyone else have this problem? Or know why this happens?
I have another issue - oil pressure fluctuation, Z-51, Dry Sump:
When the car is warming up, after driving a mile or two, I get a momentary rise in oil pressure of up to 15 psi AFTER shifting into the next higher gear. I might go to 2000-2500 rpm in first (at normal acceleration levels, in other traffic), then I shift into second, and right after the clutch engages the oil pressure surges from a few pounds to perhaps over 15 psi (as high as 60 psi a few times) and then drops back down to normal, which is between 35-45 psi at normal lower engine RPM's. Same with the next upshift. It barely does it, if at all, after ten or fifteen miles of driving.
It will do this after driving 15 miles (oil temp rising, maybe at 150-160 degrees), if I park to buy a few items in a store, then come back out and start up again.
The oil level is normal, so the oil shouldn't foam.
The voltage barely fluctuates, if at all, while shifting. Some slight voltage fluctuation is usually present.
I have not been able to make this happen by playing with the throttle, but I haven't tried that hard.
Anyone else have this problem? Or know why this happens?
A lot of these do that including mine, I have a feeling they all do it but a lot of people dont have the track dash on and watch the oil pressure gauge when warming up. The oil pressure just jumps around (not RPM related) before it warms up all the way. Not sure why exactly but my guess its the ECM self testing the electronic oil pressure control to make sure it works before its warmed fully.
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Someone may have a better answer, but my C6 ZO6 does this also. I think it is temperature driven, as the oil reaches operating temperature the RPM vs Oil pressure flattens.
"The viscosity of an oil changes - dependant on the temperature, the pressure, and the actual shear stress on the oil as a result of flowing between moving components. The viscosity of the engine oil will depend on whether the oil is, for example, in the sump, the pump, the cooler, between the cam and followers, or in the crankshaft bearings.
The rate at which viscosity changes with respect to temperature is non-linear. To put this in to perspective, Graph 1 above is commonly used to ascertain the viscosity of a fluid at varying temperature points based on the two known viscosity values quoted at 40°C and 100°C. In order to draw a straight line, the viscosity is plotted as logarithmic function against the linear temperature scale.
To put this into perspective, this means that for a 10°C increase at low temperature, the viscosity may thin out by more than 500cSt. However, the same 10°C difference at normal running temperature will result in a change of less than 5cSt."
Oil Viscosity Explained
My Z51 is the same, and I recalled GM talked about the C7 having a variable displacement pump. This was in an early press release, "The LT1 oiling system – including oil-spray piston cooling – was also optimized for improved performance. It is driven by a new, variable-displacement oil pump that enables more efficient oil delivery, per the engine’s operating conditions. Its dual-pressure control enables operation at a very efficient oil pressure at lower rpm coordinated with AFM and delivers higher pressure at higher engine speeds to provide a more robust lube system for aggressive engine operation."
Explains the lower pressures. It's more than the oil viscoity!
Actually the lower pressure is because they moved the oil pressure sender to the front of the engine and it reads oil pressure after it goes through the engine as opposed to the 'old' LS engines with the sender in the rear that came off the oil pump before it went through the crank/cam/lifter galleys. GM release said 7-10psi lower than LS engines.
From another GM release:
"Things are similar with the oil system, which incorporates a variable-displacement oil pump akin to those on AFM-equipped Gen IVs (still driven off the snout of the crank). Completely new on the LT1 is the oil pressure sensor’s location, which now reads from the front of the lifter galleries instead of the rear: readings are lower here by several psi due to it being further downstream in the oil’s circulation path through the engine. Getting the best possible reading on system pressure is crucial not only for AFM operation, but since the main and cam bearings are fed by the lifter galleries and so are at the final points in the oil’s circulation (recall some aftermarket LS blocks’ use of so-called priority main oiling to get around this perceived weakness)."
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My oil pressure pocket gauge has a delay before it starts to rise when starting. Is the location of the sender the reason, or is the update of the reading delayed by instrumentation initialization? It does not make any difference if the engine is cold or hot when starting. I have not compared to the readings in Touring or Track mode because I always drive in Sport mode.
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That's the gauge initiation routine, oil pressure doesn't start reading for a few seconds but other things are initializing too so it's normal. Threw me a bit when I changed the oil since that's my indicator the car is pumping the oil I just poured in.
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Does anyone know for sure that the oil pressure and volume is regulated by electronics? I was beginning to think it was caused by a defective pressure sender.
When will those service manuals become available from Helm so we can see what this thing is really made of? It was promised in February, or March, then April then August and now it's November.
When will those service manuals become available from Helm so we can see what this thing is really made of? It was promised in February, or March, then April then August and now it's November.
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I just changed mine to Mobil 1 and its now running a bit higher, still the same for the most part at idle but on full throttle its getting as high as 45-47 at times? Should I be concerned, check level after operating temp and 5 minutes or so cool down and seems to be where its supposed to.
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Oil pressures these days are a lot lower than they were decades ago. Even 20 years ago, they were running lower oil pressure. I have a 1996 Oldsmobile Aurora with a Northstar 4 liter engine. I run 5w-40 oil in it. When it is cold, the oil pressure is about 70 psi at 2000 rpm, but when warm, this falls to about 42 psi, and at lower rpm, down into the 30s. At idle, when warm, the oil pressure falls to about 15 psi. According to the manual, anything over 12 psi at idle is normal.
The old rule of thumb, from long ago, was that you should have 10 psi for every 1000 rpm. I doubt that still holds with engines running at 6600 rpm, but it may give you some idea of how low is too low.
The old rule of thumb, from long ago, was that you should have 10 psi for every 1000 rpm. I doubt that still holds with engines running at 6600 rpm, but it may give you some idea of how low is too low.
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