Tom M'Guinn

The big 24mm crank bolt does affect oil pressure. It needs to be tight to drive the oil pump. Did you re-torque to the high torque spec (155 ft lbs if memory serves)? If the new pulley flat and not bent or twisted where it mates up? If you removed anything else on the crank, did you replace in exactly the same order with nothing backwards, etc.?

Fishey

Broken Oil Pickup Tube or bad O-Ring sealing it to the pump.

/Thread

-Your Pal
Fishey

dally_de

i have replaced only the pulley...but probably it isn't tighten enough ...i tighten with a normal size key and for sure it isn't tighten to 155lbs...as because of that in the first place the pulley bent (i took it to a local shop for changing the oil pump seal and they didn't tightened the pulley and it bent and got loose )and i do not know if the original washer is in place ..anyone have a photo on how it looks?

txhokie4life

Any updates on this thread?

I have a 951.
I was exhibiting the same issue last year -- and I ended up coming off track with 0 OP.
Spun the #2.

Completely rebuilt the lower end. Replaced the pick up tube, oil pump.
added baffle, crank scraper.
Turbo was rebuilt prior to engine rebuild. Balance shafts have been deleted
during rebuild.

I get maybe 3.5 bar at idle at startup.
As it warms it drops down to 2 bar -- maybe a tad less.

There are times before its warmed up that OP will fluxuate about 0.5bar,
almost like an electrical issue -- did this before and now it does it now.

Since I obviously lost enough pressure to spin a bearing - I think this is real
and concerning. At the moment I'm running Castrol GTX 10W40 as a break in the
engine -- and will move to 20w-50 VR1.

I have not verified with a mechanical gauge yet.

The OP sender was replaced (with a used one) -- but odds
of two acting the same and being bad are low.

My mechanic pulled my OPRV and said everything looked fine.
And realigned it - we haven't had a chance to refire it back up
yet - working on another glitch -- but I should be back up
this weekend.

My chumpcar runs 5+bar and 4-4.5 hot. So does a buddies 951 race car.

So something is up. I don't dare go back on track until I get this resolved.

thanks,

Mike

Arominus

Did you replace the O-rings in the OPRV?

J Berk

The drop down to about 2 bar at idle when hot is totally normal.

The 3.5bar at cold start is not.... It should peg at cold start and drop down as it warms up.

The bounce reminds me of a bad connection issue I had with my car... The end of the wires that conect to the sender were bad (might be 1wire...can't recall)... Cut back and repaired and no more bounce