I rebuilt the motor in my car last summer and I have not been happy with the oil pressure ever since. I noticed that the parts diagram has two valve like parts listed to go in the head. I pulled the cam towere off the old motor and took a picture of the valve that is installed. I gave the entire head assembly to the motor shop to get checked and cleaned. They gave me back all the old valves and parts that were removed. One dowel pin was taken out and had to be replaced. They also bead blasted the head. I however do not remember anything specific about this particular valve assembly. Does anyone know the symptoms if this part was bad or missing? Also is there a different part for N/A's vs. Turbos? I have gone through every external cause for the strange oil pressure I am getting and I am down to replacing and re-sealing the oil pump. If I can help it, I want to make sure that is the last resort.
The symptoms:
4.5-5 bar at cold idle
2 bar hot idle
4 bar 5K rpm luke warm
3.5 bar cruising long distance
3 bar or less @ 5k -racing (when I call it quits and pull in)
also when I hit the gas driving at one speed the oil pressure drops, when I let off (coasting down hill at the same speed and RPM) the oil pressure goes up .5-1 bar. This has been confirmed with a mechanical gauge.
Fuel pressure checks out OK. 30psi at idle and 15psi after 20 minnutes. Closer to 40 with the vac. line pulled. Checks out with the specs from Haynes. There was a theory that it was running way lean and heating up the oil far beyond the water temp. (H2O temp is nearly always perfect) I still havent checked out the pump volume, but its not as likely at this point.
Any ideas other than another full rebuild are welcome. I want to find out what I did so the same mistake is not repeated on the next motor.
Thanks!
-Greg
P.S. if anyone has a DME for an 88 with the last digits ending in .05 I am interested. Even if it needs resoldering or has a chip. We bought one that ended up being an 87 DME (.04)