Seems like oil pressure problems are abundant these days huh?

Anyways, here's the jist. Freshly rebuilt motor, just over 2k on it and break-in recently ended. I installed an Autometer Electric Oil Pressure gauge mounted via the racing beat pedestal adapter to verify the numbers in case the stock one was junk. Here are my results:

Cold -
Idle stock gauge = 30psi
Idle Autometer gauge = 35-40psi
3k stock = 60psi
3k Autometer = 75+psi

Warmed up to operating temp -
Idle stock = 0 or barely above
Idle Autometer = 0 or barely above
3k stock = 30psi
3k Autometer = 35-40psi
7k stock = somewhere just above 60psi
7k Autometer = Over 75psi

I was running cheap Sears brand 10w30 during the break-in for my motor because I didn't want to waste expensive oil due to the 500 and 2000 mile oil changes so I was hoping it was just that crap oil. However, I changed my oil to Redline synthetic 20w50 and a new Atkins Rotary OEM spec oil filter. Something to note, though, is that the cold oil pressure after the oil change was much much higher than before, but after it started to warm up it began to drop again to where it was before. Could this possibly be because it was then mixing with the other 10w30 sears oil that was in the oil cooler and engine already? I know it's a long shot and I doubt this to be the answer to my low oil pressure problems, but I thought I'd ask.

History of engine. I did the rebuild not because it needed it but because I wanted to port. Engine had ~150k and ran great. Idled perfectly, fair compression, no smoke, and oil pressure (as much as I can remember) was normal. No seals or anything were blown prior to the rebuild. Engine now runs perfectly. Fires up on every try hot or cold, never floods (hardly did during the rebuild even), idles perfectly solid when warm (a little brap to it when cold though, but that is most likely due to mods), and is very smooth driving.

Oil related things I can think of that were done during the rebuild. New o-rings, used atkins viton oil rings, put in corksport SS oil cooler lines, inspected other oil related things during rebuild everything looked fine, used an Atkins thermal bypass pellet, when I did the oil change today there were no sparkles or metal shavings at all in it after being drained, and that's all I can think of right now but feel free to ask me questions.

Also another thing to note that I think might be contributing but am not sure. During the rebuild I put in a rebuilt rear oil pressure regulator good for 80-85psi however I DID NOT SHIM the front regulator. Could this cause these problems? I forgot to shim it and haven't gotten around to it since I put the engine back in. I will be doing this soon hopefully to see if it helps.

My symptoms seem weird because idle seems way low, 3k or so seems a tad low, and up to redline it seems fine (reaching over 75psi with the unshimmed front regulator). An idea I had came from reading a how-to on nopistons about e-shaft oil mods where you replace the ball and spring under the large screws with carb jets. Doing this gave much better pressure and flow at higher rpms however at idle they said oil pressure could and would drop to near 0 or at 0. They said to remedy this you'd want to get an 80-85psi rear OPR and shim the front one. I was wondering if the ball/spring might have had something go wrong and are now stuck "open" all the time in a way like these jets would cause? Is that possible? And if it is would it be causing these symptoms? Because it seems to follow the oil mods they describe for the e-shaft. Just curious...

That's all I can think of for now for information and questions, please if you have any ideas or suggestions don't hesitate to help me out. And if there is any more info you need to know I'll be glad to do my best to answer your questions.

Thanks.

 

One other thing. The readings I got for idle and warmed up for psi were taken in neutral in my driveway. One thing that might be worth noting is that when I was driving while monitoring the Autometer gauge it seemed to only be at about ~30psi with load at 3k rpms when fully warmed up, yet in neutral it was higher? I dunno just throwing it out there. And while driving with the engine cold at 3k it was over 75psi easily, in neutral it was a little above 75psi.

 

does the autometer unit use the stock sending unit?

 

No of course not. The autometer one comes with a new oil pressure sending unit that must be threaded in somewhere, for me I put it into my RB oil gauge pedestal adapter.

 

http://www.mazdatrix.com/faq/oring.htm

 

I've already read that, and from searching if it was a front cover o-ring my oil pressure wouldn't be increasing with rpms right? Well it does, so that's why I thought it wasn't this.

 

Not really. I installed the o'ring wrong. The oil pressure increased with higher rpm. That's normal. The next time I installed it without a gasket altogether.

Or it could be something else altogether. Who knows til you take it apart. In the meantime keep the rev's up to keep the pressure off zero. But you know that.

 

That's true but I was hoping by listing all of my symptoms and info someone might have an idea as to what it could be. This weekend I'm going to shim the front regulator in hopes that it actually does something but I'm doubtful. If it doesn't I'm just going to pull the engine and replace everything that the FSM trouble shooting guide says to for low oil pressure (oil pump, pickup, etc.) at once as well as checking some o-rings and hope that it gets fixed (I have like 3 replacement oil pumps and 4 or 5 pickups to work with so I'll pick the best looking ones I can out of that). This is of course if no one on here suggests anything before then or makes some really good guess as to what it is.

 

man that sounds like a pain in the ***! Good luck man. It sounds like when you get really far in a video game and forget to save the game so you have to do everything all over again hope the shimming works for you man!

 

Yah I hope too, that'd make my life a whole lot easier, but I doubt it will. Good thing I have almost all the parts that are supposed to be checked/replaced according to the FSM.

 

When I changed my oil from 10w-40 to 20w-50, my car started to do that thing where you say when its cold, the oil pressure is higher, but as it warms up, it drops - the only thing is... mine drops back to 30psi, not 0.

I figured that it was the thicker oil creating higher oil pressure, since 20w-50 when cold is some pretty damn thick stuff.

 

i'm at work so i don't have time to read all of that but here is a possibility.

sounds possibly like a blown out front cover o-ring or a cracked casting somewhere. do not drive the car with near 0 pressure at idle when warm, it will blow your turbo at the very least...

did you do any rotor oiling jet modifications?

 

I wouldnt bother with shimming it, it's not causing this problem. If the relief was bypassing oil at idle causing the pressure to be low, it would be bypassing @ higher pressures also. Sounds to me like you have a front cover o ring problem like others have mentioned.

 

Read the whole thing when you get back, some of what you said is answered. And I don't have turbo.

 

disregard my post then, my home connection is fubared so i won't be able to follow up on it.

 

Bumping this to ask for some opinions.

Rather than guessing and checking and spending lots of BS time hoping I guess right on what the problem is I've decided to just do it all at once. I want as little downtime as possible so what I'm planning on doing is on Friday (got midterms for college during the week so I need to wait till the weekend) is pull the engine and do things from the FSM troubleshooting guide as well as some other stuff I've read about from FAQ's and such. Here is my list:

- Replace oil pump with a spare one I have
- Replace oil pump gear with a brand new one
- Check oil pump chain with the other 3 I have and choose the best one
- Check the oil pickup with the other 4 I have and choose the best one
- Replace oil pressure control valve and shim
- Replace oil cooler bypass valve
- Put in a brand new rear 80-85psi adjustable oil pressure regulator
- Replace front cover gasket with a new o-ring
- Replace the E-shaft bolt o-ring
- Replace eccentric shaft thermo spring
- Already have the thermo bypass pellet


So what do you think? Is there anything you'd add to the list? If so why? Give me your opinions and reasoning if you have a suggestion, please, don't just post "do this" and not say why. Is there anything on that list that is completely useless to try for whatever reason? If so please tell me and why.

Thanks for any help.

 

I have the same problem that I'm still dealing with after a little over 4 months.

I've replaced the front cover o-ring twice, using just RTV and a little silicon gel to hold the oring in place while putting the cover back on.
I also now have a thermal pellet, I had hoped that the factory one was just sticking.
If you think it's the oil cooler bypass pellet you can try running the car without it to see if that effects anything.
You can always check springs to see if they meet factory specs, no point in replacing them with new ones, cause springs usually don't wear out.
If any of the other things you mentioned work out please tell me so I can have some guidance.

 

Yes I'll update this if it does or doesn't get resolved with the parts I listed.

As for the springs, I'm replacing them anyways because I want to do this all at once. I don't want to order some parts and inspect the springs while the motor is out just to have to pull it again and order the springs if they aren't within spec. Besides the two springs aren't very expensive.

 

Bump for more opinions on the list of things I'm going to replace.

 

Update.

Well I'm pretty sure I found the problem, or problems I should say.

Front cover o-ring was completely gone. Apparently I have an 88 but with later casting and I needed the teflon retainer but didn't use it on the rebuild. The o-ring was destroyed and caught in the pickup strainer.

My front relief valve regulator (the spring under the front cover) was also out of spec along with my e-shaft spring too! Then I go to check my oil pump and whatcha know, it's out of spec as well.

So I replaced all of those things and a couple other parts and got it all back together. Had to let the silicone dry so I'm going to be firing it up today to see how it turned out.

 

My oil pressure problems are officially fixed.

When cold I hit 60psi on the first startup on the stock gauge for idle oil pressure, but that could be thanks to the 85psi rear OPR and shimmed front spring.

Anyways, after it got to op temp I had ~20-25psi on my autometer gauge at idle (850rpms) and just a tad under 30 on the stock gauge. At 3k rpms on the autometer I was at 75psi and on the stock gauge it was past the 60psi mark.

So that's good news I guess, here's a list of everything I replaced:

- Racing beat 85psi rear OPR
- New stock front oil pressure control valve (spring under front cover) and shimmed it with 2 M5 washers
- New stock e-shaft spring
- New main e-shaft bolt o-ring
- New stock oil pump drive gear
- Took the best parts from my 3 n/a oil pumps and built one that was within spec (the one I had in there was a tad out of spec)
- Changed front cover o-ring with teflon retainer
- New front cover gasket
- Known good/clean oil pickup strainer

I think that's it. I'm happy it's all fixed now and makes me feel a lot safer.

 

ya know, I never checked my e-shaft spring to see if it was within spec. thanks for the list dDub.

 

No problem, I actually found it interesting it was indeed out of spec. Goes to show simple things might actually be the problem I guess.

 

My oil pressure was always really low at idle too, almost 0, though it went up to 50ish at 2-3k rpm and peaked at about 75. My bearing clearances were all .004in. (at the limit basically), and I installed the front cover O ring correctly. I've never seen any problems with the bearings on subsequent teardowns of the engine, so I don't consider low oil pressure at idle a problem if the pressure comes up at 1000k rpm, which mine always has.

At idle, there is hardly any load on the engine; it's just producing enough torque to overcome its small amount of rotational friction, so I doubt there is much pressure on the bearings.

 

Yah I figured as much as well, but the lower rpms were lacking too which was evident of some things I found upon removing the front cover. Front cover o-ring was completely gone, e-shaft spring was out of spec, front oil pressure relief valve spring was borderline, so yah I changed them. Now everything is fine.