Strangest Oil pressure problem I have ever encountered. Brain Buster!!
07-19-06, 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
07-19-06, 07:26 AM
#27
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
07-19-06, 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.
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.
07-19-06, 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
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.
Sorry, lubricating systems aren't my specialty.
The vacuum system cannot and does not have anything to do with oil pressure.
07-19-06, 09:51 AM
#30
Haven't we ALL heard this
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
Honestly, isnt't that the ONLY thing you have not checked in the oil system?
James
07-20-06, 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!
07-20-06, 02:37 AM
#33
Haven't we ALL heard this
Originally Posted by Karack
AHHHHH
hey, don't forget about those big metal triangular things in there too!
hey, don't forget about those big metal triangular things in there too!
07-20-06, 03:06 AM
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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?
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.
07-20-06, 06:53 AM
#36
https://www.rx7club.com/rotary-car-performance-77/aluminum-rotors-why-not-557805/
There's some discussion on aluminum in our engines (specifically rotors).
There's some discussion on aluminum in our engines (specifically rotors).
07-21-06, 12:48 AM
#37
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!
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!
07-21-06, 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,..
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,..
07-21-06, 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.
07-22-06, 01:57 PM
#42
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!
Yes I have pissed of the rotary gods and they can **** off. I sacrafice enough money to them while owning this car!
07-22-06, 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
also it could maybe be the wire between the sender and the guage
07-23-06, 02:13 AM
#44
Haven't we ALL heard this
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
also it could maybe be the wire between the sender and the guage
James
07-23-06, 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.
10-19-06, 11:41 AM
#46
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.
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.
10-19-06, 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.
IF so, then don't. Use the mechanical gauge even if you have to tie the thing to the wipers on a long hose.
10-19-06, 11:04 PM
#48
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.
It's good.
10-20-06, 06:32 PM
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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 ****!!
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 ****!!