Castrol 5W50 low oil pressure!!

[moribundman]

quote:

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My idle oil pressure was around 15 PSI using AMSOIL 5W40 during Hot july days.

In the morning right after start up my oil pressure goes to 50 PSI with AMSOIL the needle would go all the way to the max (Over 80 PSI)

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Oil pressure at idle should be between 15 and 35 psi, so your oil pressure was already at the low end with the Amsoil.

Check oil pressure at 3000 RPM and 80 degree C (176 F). If it's less than 45 psi or so, I bet your crank bearings are shot.

 

[kickster]

Pressure at 3000 rpm with AMSOIL is around 30 PSI. My other VW has the same oil pressure.
My sensor is in the head not on top of oil filter. Pressure in the head is always less.

Trust me the bearing are doing fine. This is a semi race car that I race on track. The idle pressure is lower than normal due to aggressive cam that I have.

 

[Jimbo]

After trying it, I am not a Syntec fan. While your problem sounds strange, 5W-50, even in a synthetic, is quite a trick.

My BMW did not even like 10W-40 Syntec compared to 15w40 Delo, huge difference in oil usage and slightly more valve noise. I do not have a pressure gauge, but the light never came on.

 

[CBR.worm]

You have an aggressive cam that lowers oil pressure?

 

[kickster]

yes at idle. It idles rough. Jumps from below 500 to 1000 rpm constantly.

 

[moribundman]

quote:

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Pressure at 3000 rpm with AMSOIL is around 30 PSI. My other VW has the same oil pressure.
My sensor is in the head not on top of oil filter. Pressure in the head is always less.

Trust me the bearing are doing fine. This is a semi race car that I race on track. The idle pressure is lower than normal due to aggressive cam that I have.

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You know, you keep coming up with additional little tidbits like location of your oil sender units and aggressive cams. Are we supposed to know about your mods intuitively? And yet you're snippy to the point of being rude. You ask us questions, while it appears you only want confirmation that it's the oil's fault. Maybe you ought to call Castrol and bring your concerns regarding their product to their attention, but don't forget to mention all the mods that might affect your rebuilt engine.

So you have such aggressive cams that the engine lopes like mad? Seems reasonable to me that oil pressure will drop with RPM under those conditions.

 

[Winston]

Mori, you are right how people often come he wanting confirmation of their opinion, then they are irritated when more info is requested. But, that is just how people are.

 

[Dr. T]

I'm a regular user of Syntec 5-50 and by the urging of this board I have tried GC and BC. I will tell you that the 5-50 is DEFINATELY thicker than either one of those 2 oils. Both in throttle response, engine noise and minute fuel economy differences.

In other words, quieter and smoother running with the 5-50...this is the grade I'm back to using...(with some LC of course

)

 

[Dr. T]

 

[uconn1150]

quote:

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Originally posted by Dr. T:

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Dr. T,

Is this stuff still GRP III?

 

[KW]

You might have a bad oil filter. It might be worth changing it before dumping the oil.

 

[Titan]

My rudimentary understanding of oil is that a slightly thinner oil should show a lower pressure at a given rpm. However, there is a corresponding higher FLOW rate. Since flow and protection are basically usually directly related, it doesn't sound like a problem...especially if it is occuring at idle, when there is little heat stress. Now, if your engine is experiencing a decreased oil pressure from that engine's factory specification at normal operating temp and normal rpm's...THEN, I'd say you MIGHT have an oil viscosity-related problem. Remember, I'm not an expert.

 

[99]

Go back to what you used to use and see if the noise/low oil psi goes away. It should.

How does a bigger cam lower your oil psi? Doesn't make sense to me.

If your idle is surging and rough like you say, you probably have a vacuum leak somewhere. The only engines I know of that have a idle that has a 500 or so rpm variance are roots blown engines-a professional monster truck is one of them. Other engines with bigger cams just have that bumpity-bumpity-bumpity-bump sound-no surging.

 

[hominid7]

VW's like thick oil. My 1989 Jetta would not keep its oil light off with anything thinner than a 15w40. So I used conventional 20w50 year 'round for the 225,000 miles i drove it with never an oil related problem.