Remember that youre reading oil pressure off an OEM sensor and OEM gauge … I would definately add a quality oil pressure gauge.

Tell me again (I know it’s above)-
what oil viscosity are you running?
What were your oil bearing clearances?


I am experiencing the complete opposite … in that I have high / higher oil pressure than what you’d expect (until it warms up), I didnt add pressure shims, but I am running a 40wt oil

 

have high oil pressure at startup also but it drops when hot
im using 6qts of Driven Racing Oil BR30 5w-30 Conventional Break In Oil
mains are ACL race series 4M2633H (standard size) rods are King-bearings CR6775XPSTDX (standard with extra oil clearance) everything had really nice tolerances when I checked before assembly from crank journals to block and rod bores everything was measured with either a dial bore gauge or micrometer and I mean everything was checked I even replaced the piston oilers in the block and replaced the oil gallery gaskets with the new steel reinforced models for higher oil pressure. And when I had the new heads done at the machine shop I had them check all the tolerances and everything was extremely healthy I don’t know what I could have missed. I’m going to pickup a mechanical oil pressure gauge and try and get an actual numerical value

 

What are the actual Bearing Clearances?

Anything more than OEM Spec and you will need to go up in oil weight.

Try 10w40

 

Ordered an AEM oil pressure gauge this morning should be here Monday, later today I’ll pickup an mechanical gauge and may switch to 10w40 if needed it’s probably to hot out to run 30wt oil when it’s 110 outside
I have the clearances written down somewhere but I can’t remember off the top of my head all but the rod bearings are oem spec but the extra rod clearance was intentional and also why I went with higher pressure on the pump

 

I think dropping 40wt oil would be a good check … relatively inexpensive and near-instant feedback.

I should drop down to 30wt oil and see if it drops my oil pressure?

I dont think ambient temps are too too impactful on the engine (outside of intake temps??) but the car runs at 210-220 degrees …

And dont sell the car! You have wayyyy too much in to it to give up!

 

I have this same issue with a high oil p at startup and have switched to a 0w-40 that has helped quite a bit with the high startup pressure but reasonable once warm.

 

Oh I’m not going to sell it, you know the frustration just makes it feel like that would be easier sometimes. Any who I’m going to try either 5w40 or 0w40 and see what that does. Btw what port are people using for the oil pressure? I could “t” off the oem sensor or I could pull from the port after the oil filter, kind of aiming towards the later

 

Update: went to drive it today and I had the opposite condition of yesterday, car was idling at 60 once warmed up but after a few minutes of driving oil pressure stayed between 90-120+ seams like a good indication that the oil sending unit is going bad. I did pick up a mechanical oil pressure testing gauge, just haven’t installed it that will probably have to wait till the weekend

 

You can tee off the oil pressure sensor port or you can get a M14x1.25 fitting and there is an post-filter port right above the oil port (I’ve probably mentioned it before).

 

yeah I used the post filter port to pre oil the engine and I’m leaning that way since I already have the fitting and would rather measure post filter

 

a lot to scroll through so i will just ask,

your intake, that custom? metal used? thickness? im in the process of fabn one up ,have two designs that im thinking of,

 

the manifold is a kinetix the piping is a modified dc sports CAI

 

If my Mocal adaptor came with a port I would've used that, but I've teed off the OEM sensor location to add a digital gauge. Works a treat.

For comparison's sake with your pressures, I use 5W-40 and start at about 80psi cold and settle at around 50psi at operating temp. Rev Up pump and gears.

 

Ok got the mechanical gauge setup and it’s definitely the oem gauge or sensor. I used the port after the filter so pressure is likely lower than what the sensor should be seeing. probably going to switch to a 0w30 oil to help with the high initial pressure


Startup about 106-108psi

At temp 18-15 depending on idle

 

For got to post the oem gauge readings for comparison, it’s possible this is actually what it’s seeing pre filter but I needed the piece of mind of the mechanical gauge, I’m running the 108 filter right now and will switch to the 110 filter when I go to 0w-30 also still not sure why the gauge was showing almost zero earlier in the week unless the sensor really is going bad


Startup

After warmup

 

Changed the oil and filter now ruin 0w-30 and the m1-110a filter and it is much happier with a cold starting pressure I’m much more comfortable with. I took the time to remove the sensor and clean the connector and wiring with contact cleaner and put a bit of anti-corrosion contact grease on the connector still didn’t do anything, but I think I have an idea of what’s going on. I noticed when I switch the ignition to the on position before cranking the gauge runs up to 60. Also the battery keeps running down and I keep getting the p1235 code for throttle sensor voltage correlation. So I’m wondering if I have a grounding issue again. I haven’t modified the harness since last time so it might be how I have the engine and battery grounds setup. It’s too hot out now for any additional work so I’ll wait till Tomorrow morning to take a look at it and then report back what I find

un-related: does anybody know what the normal vacuum at idle is? I installed a small vacuum gauge on the manifold and am just curious, I’m reading 15-17 In/Hg

 

Yea - likely the sensor … the sensor goes straight to that gauge and I dont know that I’ve ever seen anyones gauge go out.

It seems like I replace those pressure sensors every 15k to 20k miles or so … recently I purchased an AEM stainless steel sensor and I re-wired the connector to the delphi style. I hope this has better longevity.

14-15in-hg sounds right …

 

Well today I solved a few problems and found a few problems I’ll start with the boring stuff first, for those fortunate enough to not live in Texas it reached 110 Least week here in the DFW and for that matter much hotter inside sitting vehicles. I think that’s where a few of my issues originated from. Confused? I’ll explain, first I found some plastic parts on the floor under the pedals



these ended up being the switch grommets that contact the brake light switch and the clutch switch. My brake lights have been running continuously which explain the battery constantly draining. Then I had problems with the car not starting due to the clutch switch grommet crumbling currently I have bolts in place as a temporary fix.
now for electrical, I decided to install a single grounding point right off the OEM spot next to the battery, I think it came out nice and found the nasty problem causing the P2135 code. As I disassembled the old ground setup I came across the cable that grounds the chassis to the battery. It was badly Corroded, so bad in fact that it broke in half. Not sure how that happened since it was a 0/1 gauge wire I installed to replace the tiny oem 6 gauge one, but it’s been replaced with a much nicer cable with measures to prevent future corrosion. All reassembled with the new cable and grounding setup the P2135 code went away and the oil pressure gauge is reading closer to actual pressure, the idle is also significantly better


New grounding setup

Old battery cable

Im going to order all new pedal grommets from Z1 this week including the accelerator pedal and just have piece of mind

 

I like that grounding block - looks clean!

Up in Colorado, two weeks ago now (last week we had afternoon/evening rains) it was high 90s … I dont think we got into the 100s but it was hot!

Great progress!

 

Well my victory was short lived drove it about 80 miles over the weekend no problem and then this morning I went to take it to work and it threw the P2135 code again at startup and went into limp mode where it won’t let you rev the engine, also saw a pending code for cam position sensor. Both cam sensors have less than 1000 miles on them as I replaced them when I had problems with the engine harness that I cut up and eventually replaced, but it could also be a connector when it comes to this issue. Overall I’m not sure how to troubleshoot the two issues. I don’t really want to spend $200 on a new pedal assembly or a new throttle body when the issue seams to be intermittent. Still waiting on the new pedal grommets from Z1 so there is the possibility that the accelerator pedal grommet had gone bad too.