I know that high blood pressure can come with age, but high oil
pressure too? My MK 2 has suddenly developed high oil pressure. It
occurred overnight, not a slow creep. Historically, my 3.8 has
required a couple of shims on the oil relief valve spring to
maintain 40 lbs/psi at 3000 rpm when hot. It has done so for 9
years. Now, suddenly,it has an idle pressure of 30 lbs/psi and off
the scale at 3000 rpm. I checked the pressures with a manual gauge
and they are correct. I removed all shims with little change. The
pressure relief valve needle does not seem to bind at all and the
balancing valve ball and spring move easily as well. The car runs
fine otherwise. No recent oil change I’m baffled.
I know that high blood pressure can come with age, but high oil
pressure too? My MK 2 has suddenly developed high oil pressure. It
occurred overnight, not a slow creep. Historically, my 3.8 has
required a couple of shims on the oil relief valve spring to
maintain 40 lbs/psi at 3000 rpm when hot. It has done so for 9
years. Now, suddenly,it has an idle pressure of 30 lbs/psi and off
the scale at 3000 rpm. I checked the pressures with a manual gauge
and they are correct. I removed all shims with little change. The
pressure relief valve needle does not seem to bind at all and the
balancing valve ball and spring move easily as well. The car runs
fine otherwise. No recent oil change I’m baffled.
Rich Faller
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In reply to a message from Rich Faller sent Sat 26 Jun 2004:
Rich, disconnect pressure relief return hose, add longer hose and
run into a bucket and see if it is bypassing. I have not done
this ;but it would give you a good visual and you could blow some
air into pan to make sure that line is open. Nick–
The original message included these comments:
The pressure relief hose is wide open. I know, because I had to
wipe the oil off of my face when I took it off.