: The oil pressure on my slant bounces some at
: idle. When I first start it up (cold), the
: pressure is a steady 50psi. After the engine
: warms up the gauge fluctuates between
: 20-25psi in gear at idle. Same if I shift
: into neutral (it does go up a few psi). It
: dosn't bounce when driving in town or on the
: freeway, when the pressure goes up to a
: steady 45-50psi, though if I rev the engine
: up in neutral it bounces some till about
: 2000rpm. Any ideas on the cause?
: Eric W

: You are seeing the "pulse" of the oil
: pump.
: There is a releaf valve built into the pump
: which will start to by-pass oil back around
: to the intake side of the pump. As the
: releaf valve opens, the pulsing the impeller
: creates is reduced. (usually at about 50
: psi)
:
: If anything, you have a worn oil pump or extra
: clearance in the bearing which causes the
: releaf valve to open later. You may want to
: change to a high volume oil pump to off-set
: this.
:
: You must have a "non-dampened" oil
: pressure guage to be seeing this. As long as
: the oil pressure does not drop any lower the
: 15-20 psi at idle, you should be OK.
: DD