What is the spec for LS7 Oil Pressure?

[GeminiZ06]

I spent 30 minutes and have not found a consistent spec on what the LS7 oil pressure is supposed to be at idle when cold (startup), and when the oil is at 190deg F and at 235 deg F.

If someone absolutely knows what the pressure is supposed to be at idle and under load during startup, oil T at 190 and oil T at 235 - please post

Under load - I do not mean full throttle on a drag strip with slicks - I just mean under normal acceleration

Thanks in advance

FYI: mine is reading 36 psi at idle when oil temp is at 185 deg F

I haven't looked at it under load - will do it this afternoon and post

Just something that I think an owner should know and its something I currently do not

[extanker]

from helms manual 07 z06 oil psi min. at 212 F 41 kpa @ 1000 rpm / 124 kpa @ 2000 rpm /165 kpa @ 4000 rpm

[GeminiZ06]

Originally Posted by extanker

from helms manual 07 z06 oil psi min. at 212 F 41 kpa @ 1000 rpm / 124 kpa @ 2000 rpm /165 kpa @ 4000 rpm

Wow - that's really low

41 kpa is only what, 6 psi?

and 165 kpa is something like 24 psi?

Doesn't that seem low for a dry sump system that is designed to maintain a higher consistent oil P? I mean one reason for a dry sump is minimize the fluctuations in oil P and to maintain a consistently higher oil p then a wet sump system under many dirivng conditions.

[extanker]

minimum spec at 212 F.

[DennyM]

I never heard of kpa so I googled it ...
Some sample conversions
PSI = kPa
10 = 68.947
20 = 137.895
30 = 206.842
40 = 275.790
50 = 344.737

[No Doubt]

Originally Posted by GeminiZ06

41 kpa is only what, 6 psi?

and 165 kpa is something like 24 psi?

Doesn't that seem low for a dry sump system that is designed to maintain a higher consistent oil P? I mean one reason for a dry sump is minimize the fluctuations in oil P and to maintain a consistently higher oil p then a wet sump system under many dirivng conditions.

Oil pressure is not as important as volume. Stated another way, the rate of flow is more important than the pressure. For example, a hydraulic system can (and should) have great pressure, but zero flow. Oil lubrication depends on flow to aid in cooling and thus oil that is moving will carry heat away. Oil pressure is a consequence of restriction to flow and is easier to measure than flow rate. If the oil pressure were to read zero then it indicates either no flow whatsoever or a massive leak. In either case an engine would not last long.

kPa is Kilopascals...

41 kPa = 6 psi
124 kPa = 18 psi
165 kPa = 24 psi

[tjwong]

I recently installed a cam into my new Z, my car at normal cold start start up makes about 60 PSI and drops to about 50 when its warm. After the cam install I didn't like the cam so I removed it, installed a smaller cam. Upon start up I noticed that the oil pressure on the dash was half of what it was. Thinking that I may have got a bit of crude in the oil pump that may have stuck the bypass valve, I replaced the pump, which netted the same results. So I tore it down again, removed the camshaft and mic'd the cam bearing journals and inspected the cam bearing. Nothing wrong was found, put it back together and measured the oil pressure at the front of the block where the oil galley has a port opening. At that point on cold start the engine has 65 PSI, but the dash reports half at 35 PSI. Later I replaced the sensor thinking it was bad, same issue, removed the intake manifold and installed a manual gauge there, low and behold the oil pressure is the same as reported on the dash and its low. When cold its about 35 when its warm it drops to 12 at idle but will raise to maybe 40 if rev'd up to 3500. I know it was OK, before the only other thing that was done during the cam and head swap was that the lifters was replaced with the GM Racing Cadillac performance lifters. I am now in the process of replacing them with the OE LS7 lifters in hopes of curing this issue. Has anyone else come across anything like this?

Before anyone asks if the oil pump is sealing to the pan, yes it is, that was checked over and over. Oil filter was also replaced.

[allanlaw]

That minimum pressure spec is b.s. If your car consistently shows pressure that low, chances are the engine will freeze up or grenade within a few months - I know of a number of cases where that was the only indication that something bad was about to happen. Unfortunately the dealers will not be able to do anything for you (since the pressure is within spec) until it comes time to replace the engine - hopefully at a time when your warranty is still in effect. GM has not said what causes the problem. BTW it only happens in a very small number of cases, and the only ones I know about were '06's.