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Cold engine oil pressure

Old 07-01-2010, 03:37 PM
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Default Cold engine oil pressure

I see as much as 80psi oil pressure on my engine when it is cold - using Motul's fully synthetic (double ester) 300v Power 5w40.

Gauge sensor is in stock location.

ISTR that the pressure relief valve should kick in at 60psi?? What pressures are others seeing? Pressure is normal once warmed up.

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Old 07-01-2010, 04:36 PM
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Sounds like a sticky valve. One of my B6s shows close to 80-90 PSI when revved cold, the other reliably limits to 60. Haven't blown any oil filters yet, so I'm not seeing this as a huge problem.

The important question is: how's the pressure at idle?

edit: Wait a sec, don't you Brits read your oil pressure in bar? You're screwing with my prejudices here.
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Old 07-01-2010, 08:05 PM
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We see really high cold pressures on our STis at work with that weight 300v...it is pretty thick when cold.

Fantastic oil but quite expensive.
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Old 07-02-2010, 01:01 PM
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Isnt a new oil pressure relief valve specced to 90psi?

After installing a new pump, i got 90psi cold idle (and pressure relief valved above that) and about 15psi hot idle.
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Old 07-02-2010, 01:57 PM
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Originally Posted by Joe Perez
Sounds like a sticky valve. One of my B6s shows close to 80-90 PSI when revved cold, the other reliably limits to 60. Haven't blown any oil filters yet, so I'm not seeing this as a huge problem.

The important question is: how's the pressure at idle?

edit: Wait a sec, don't you Brits read your oil pressure in bar? You're screwing with my prejudices here.
At least it sounds that I am not alone.

Cold start idle (1200rpm) I see 55 to 60psi, hot 27 to 29psi.
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Old 07-02-2010, 01:59 PM
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Originally Posted by fooger03
Isnt a new oil pressure relief valve specced to 90psi?

After installing a new pump, i got 90psi cold idle (and pressure relief valved above that) and about 15psi hot idle.
If true this is a very interesting piece of information. My pump was new when the engine was re-built. 15k or so miles ago?
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Old 07-02-2010, 02:01 PM
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Originally Posted by miatamania
We see really high cold pressures on our STis at work with that weight 300v...it is pretty thick when cold.
Seems to be so. Shows notably higher oil pressure that the previous 0w30 Amsoil signature series oil - about 5psi or so.
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Old 07-07-2010, 01:10 PM
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A thicker oil is going to have a higher resistance to flow, so it will create a higher pressure in the system. A 5psi increase from 0W to 5W doesn't seem unusual.
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