2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Strangest Oil pressure problem I have ever encountered. Brain Buster!!

Old Jul 19, 2006 | 06:19 AM
  #26  
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mag

The magnet aint gona do **** when you have aluminum bearings, aluminum housings and an aluminum oil pump. Did you ever find the problem? I too, have a problem with oil pressure. I want to replace the oil pressure regulators, but I dont want to do all that work and find out its the oil bearings. AHHHHH
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Old Jul 19, 2006 | 07:26 AM
  #27  
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Originally Posted by KBSRX7
The magnet aint gona do **** when you have aluminum bearings, aluminum housings and an aluminum oil pump. Did you ever find the problem? I too, have a problem with oil pressure. I want to replace the oil pressure regulators, but I dont want to do all that work and find out its the oil bearings. AHHHHH
The whole engine isn't aluminum.
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Old Jul 19, 2006 | 08:52 AM
  #28  
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Originally Posted by Aaron Cake
You're wrong.

If you open the FSM to the chapter on lubrication, you will see that oil pressure is directly controlled by two regulators: one in the front cover and one on the rear iron. The front cover regulator opens at very high pressures, 100 PSI or so. The rear regulator opens at regular oil pressure. Both these are spring controlled, and unlike the FPR, are not vacuum regulated.

The pressurized oil gallery is sealed (as it would have to be) and uneffected by the vacuum system.

The purge valve only pulls vapours out of the crankcase.

It's hard to guess at what is wrong with this engine (if anything) without knowing how it was built. Like what oil mods were done, clearances tight or loose, etc.

Agreed, but it still doesn't explain high/correct oil pressure at vacuum and low oil pressure at load. If anything I'd think it would be the reverse. Do you think maybe some oil galley porting was done or some such nonsense during the rebuild? That would drop the pressure a bit I think.

Sorry, lubricating systems aren't my specialty.
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Old Jul 19, 2006 | 09:39 AM
  #29  
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Originally Posted by KBSRX7
The magnet aint gona do **** when you have aluminum bearings, aluminum housings and an aluminum oil pump. Did you ever find the problem? I too, have a problem with oil pressure. I want to replace the oil pressure regulators, but I dont want to do all that work and find out its the oil bearings. AHHHHH
This post makes my brain hurt.

The bearings are I believe bronze, NOT aluminum.

The housings are aluminum but are sleeved with a STEEL insert that is chromed.

The apex seals are steel.

Neither the housings nor the apex seals have anything to do with the internal oil system.

The eccentric shaft is STEEL, as is the oil pump shaft, drive chain, stationay gears, rotor thrust faces, torrington bearings, etc. etc. etc.

The "oil bearings"? Are those made by the same company that makes muffler bearings?

Oil pressure regulators very rarely fail. If you have low oil pressure, first verify it with an aftermarket gauge. If it truly is low, look at the common causes like a blown front cover o-ring.

Originally Posted by Boostmaniac
Agreed, but it still doesn't explain high/correct oil pressure at vacuum and low oil pressure at load. If anything I'd think it would be the reverse. Do you think maybe some oil galley porting was done or some such nonsense during the rebuild? That would drop the pressure a bit I think.
Sorry, lubricating systems aren't my specialty.
Only guesses can be made without knowing what was done during the engine build.

The vacuum system cannot and does not have anything to do with oil pressure.
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Old Jul 19, 2006 | 09:51 AM
  #30  
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I REALLY like the post that mentioned....that you have no idea what the Eshaft oil jets look like since this is a rebuild you didn't do.

Honestly, isnt't that the ONLY thing you have not checked in the oil system?

James
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Old Jul 20, 2006 | 01:48 AM
  #31  
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Originally Posted by KBSRX7
The magnet aint gona do **** when you have aluminum bearings, aluminum housings and an aluminum oil pump. Did you ever find the problem? I too, have a problem with oil pressure. I want to replace the oil pressure regulators, but I dont want to do all that work and find out its the oil bearings. AHHHHH

Well its a damn good thing we have steel bearings (coated in copper and indium), chrome plated steel lined housings, and a steel oil pump gearset then!
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Old Jul 20, 2006 | 02:17 AM
  #32  
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AHHHHH



hey, don't forget about those big metal triangular things in there too!
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Old Jul 20, 2006 | 02:37 AM
  #33  
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Originally Posted by Karack
AHHHHH



hey, don't forget about those big metal triangular things in there too!
ZOMG, where? I thought they were made of a tastey , toasty, and spicy mixture :P
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Old Jul 20, 2006 | 02:42 AM
  #34  
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actually if they did make a whole engine out of aluminum that would make for one lightweight high output engine. can you say power to weight ratio?
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Old Jul 20, 2006 | 03:06 AM
  #35  
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Originally Posted by Karack
actually if they did make a whole engine out of aluminum that would make for one lightweight high output engine. can you say power to weight ratio?
Amen.

I have been thinking about those aluminum side housings that RB makes. something like 50 ~ 60% weight drop from the iron stockers, and nitrided to boot.

but then, I don't sleep on a mattress full of cash at night.
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Old Jul 20, 2006 | 06:53 AM
  #36  
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https://www.rx7club.com/rotary-car-performance-77/aluminum-rotors-why-not-557805/

There's some discussion on aluminum in our engines (specifically rotors).
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Old Jul 21, 2006 | 12:48 AM
  #37  
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Wow. this thread is lasting longer then I thought.

Agree with you Aaron, this problem makes my head want to explode. The o-ring just doesn't sound reasonable to me since I get the "right" pressure at no load. Pressure was low when I checked it with a mechanical gauge after the first o-ring install. Later found out that the teflon/ring combo needed a little RTV to seal(why the standard combo didn't work the first time gets me).

Wankel7, you are right dude. That is the only part of my oil system I havent checked. I guess I will get a great look come rebuild time. **** man, you were helping me when all this **** started to hit the fan. Again, I appreciate the help.

I will make sure to take off the magnet on the filter. I will update this post if anything out of the ordinary happens with the engine and I am trying to contact the previous owner for a little more info. Thanks again guys for the concern!
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Old Jul 21, 2006 | 01:08 AM
  #38  
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Try changing the oil filter too, its cheap and even thought i dont think it could cause this its worth a shot.


Could the previous owner maybe have drilled out the omp feed hole so the pump is getting full pressure? That would explain why it lowers under hard throttle,.. I think that would be enough oil to smoke heavily tho,..
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Old Jul 21, 2006 | 03:00 AM
  #39  
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no, the OMP gear is still in place. Oil filter is brand new. It is a riddle.
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Old Jul 21, 2006 | 06:41 AM
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Originally Posted by FC3S Murray
no, the OMP gear is still in place. Oil filter is brand new. It is a riddle.
AKA, you pissed off the Rotary Gods.
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Old Jul 21, 2006 | 09:53 AM
  #41  
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Originally Posted by FC3S Murray
no, the OMP gear is still in place. Oil filter is brand new. It is a riddle.

No i mean internally, the feed hole in the front cover/frotn housing. It is a long shot but its about the only thing in the oil system tht is in any way linked with the throttle.
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Old Jul 22, 2006 | 01:57 PM
  #42  
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No, OMP is removed so the linkage bar to the throttle is non-existant. Only thing that is left even related to the OMP system is the gear in the front housing.

Yes I have pissed of the rotary gods and they can **** off. I sacrafice enough money to them while owning this car!
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Old Jul 22, 2006 | 06:39 PM
  #43  
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well if it works stationary and not under load is it possible the oil pump pickup isn't in the right place? or maybe not sealed to the engine correctly? i had a 12a that did that, same symptoms.

also it could maybe be the wire between the sender and the guage
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Old Jul 23, 2006 | 02:13 AM
  #44  
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Originally Posted by j9fd3s
well if it works stationary and not under load is it possible the oil pump pickup isn't in the right place? or maybe not sealed to the engine correctly? i had a 12a that did that, same symptoms.

also it could maybe be the wire between the sender and the guage
He verified the issues with a mech gauge.

James
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Old Jul 23, 2006 | 09:51 AM
  #45  
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The metering oil pump has nothing to do with oil pressure. The only way it could effect pressure is if the drive shaft was removed from the front cover and the oil feed port to it not blocked.
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Old Oct 19, 2006 | 11:41 AM
  #46  
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BACK FROM THE DEAD.

Well guys, it has been five months and I still am stumped about my pressure problem. The only thing that has improved the pressure a little bit is I added some of that oil additive that is really thick(forgot the name of the **** but there is always a display at any auto parts store with two little hand cranked gears comparing the viscosity of oil with their product compared to normal oil) That brought the pressure to about 45 when driving and 30 at idle on the factory gauge.

I guess another strange thing about the pressure is at start up the pressure rockets to 60psi even though my idle doesn't go above 900 rpm. Then after the engine warms up for about 15 min, it slowly goes down to 30.

Pressure still drops when load is applied while driving and rises when just running vaccum and coasting. AND it still reads "factory pressures" when reving in nuetral. I HATE this ****!!

I am concerned if my main bearings are going out now. Check out this recent thread that no one really hit up. I doubt it is engine bearings but I have put about 2500 miles on the engine since this oil pressure thread was started.

https://www.rx7club.com/showthread.p...turbo+bearings

Only reason I bumped this was to see if anyone else might of had some new ideas and to show it to some new faces.

AGAIN, thanks for all the help and concern when this started and any more input is always appreciated.

My head is starting to hurt again Aaron.
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Old Oct 19, 2006 | 04:01 PM
  #47  
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Seems to me you say you used a mechanical gauge to verify the pressure................then you leave me with the distinct impressioin that when driving that your again using the stock oil pressure gauge. Is this right???

IF so, then don't. Use the mechanical gauge even if you have to tie the thing to the wipers on a long hose.
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Old Oct 19, 2006 | 11:04 PM
  #48  
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Ha ha. Dude I am almost positive the factory gauge is working fine. It reads the same pressure the mechanical gauge read while just reving it in neutral. When I sit in the car and free rev it the factory reads damn near 60psi above 3000rpm and about 25psi at idle. The mech gauge read 28psi at idle and 59 at 3500.

It's good.
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Old Oct 20, 2006 | 12:14 AM
  #49  
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never trust any factory gauge. mine was broken, and it was doing some crazy ****.
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Old Oct 20, 2006 | 06:32 PM
  #50  
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I guess another strange thing about the pressure is at start up the pressure rockets to 60psi even though my idle doesn't go above 900 rpm. Then after the engine warms up for about 15 min, it slowly goes down to 30.

Pressure still drops when load is applied while driving and rises when just running vaccum and coasting. AND it still reads "factory pressures" when reving in nuetral. I HATE this ****!!
Mine does pretty much the same thing. Im going to replace the oil pressure regulator on the rear of the motor in the oil pan since that is the last place my problem could be.
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