What's up guys. I just recently got done doing a complete rebuild on my 2004 Coupe. The biggest changes I made are the eagle rods, wiseco 11.0:1 Pistons w/ block bored .020" over, ACL engine bearings, and rev-up oil pump. Rod bearing clearances are all at .0025" (a tad loose, I know. That was intentional) and all main clearances are at .0018". During the break in period I'm running Mobil Conventional oil in a 10w-40 weight. Now, the car starts right up and runs awesome, and it's got about 100 miles on it so far. The only problem I have is that my oil pressure seems high to me. I installed a glow shift oil filter sandwich and a glow shift oil pressure gauge, and with the car fully warm, idle is reading about 30 psi. On a cold start the pressure is almost 100 and progressively drops as the car heats up. Under load the gauge is reading 80-90+ psi. Is this something I should be worried about or is it normal for a brand new engine. There's only 3 things I can think of that would be causing it:
1. Oil weight is a little on the thick side
2. Eagle rods have no holes in the big end like oem rods do, might cause increase in pressure due to being sealed up?
3. Oil pressure gauge is wrong

 

Lets bring this back to life.. Fully built motor and was running 15w50 as per my builder. I was at 95/100 cold start and down to 30..I dropped down to 10w40 but was still 85/90 and dropping down to 30.. I'm low compression though as I boosted my car.. Thoughts? I'm running some type of oil catch can as well. I've blown my rear crank seal twice in the last 6 months too...

 

I question why he suggested such viscous oil? Typically that's only for very sloppy tolerances where you need a lot of oil takeup like diesel engines and such or EXTREME duty situations like track conditions where you're literally WOT almost all the time and need the extra protection because the motor spends it's life on the ragged edge all the time.

What's the weather like where you are? If you're near freezing temperatures + 10w-40 + rev-up oil pump for the higher volume (likely if the block was built) then I'm not surprised about the high pressure. Cruising speed, pressure of 30 is a little higher than the expected 20-25 but still within spec, startup pressure of 90 isn't enough to blow anything unless you have a clogged pcv system.

What oil are you running?

 

The oil pressure you describe is perfect! That's exactly what my '04 coupe oil pressure reads, 100 psi cold and 30 psi when completely warm after a long drive! After you have 3K miles on the rebuild clock switch to AMSOIL synthetic and whatever viscosity your builder recommends! I wouldn't use anything but WIX oil filters, they do a better job filtering than any filter on the market...my opinion!
Gary

 

The rear crank seal blowing leads me to think you don't have adequate crankcase ventillation and are getting excessive blow-by gas into the system that isn't being relieved.

Inspect this catch can and your pcv valves to make sure those gasses can actually vent. Install a gauge if needed to measure. It's also possible that whoever installed the first and second rear main seal simply nicked it on install. It needs to be handled VERY carefully because it's super easy to.damage.