Strangest Oil pressure problem I have ever encountered. Brain Buster!!
07-15-06, 03:04 PM
#1
Strangest Oil pressure problem I have ever encountered. Brain Buster!!
OK, if any of you guys have read my previous oil pressure threads you will know that I had encountered some problems that have been discussed and fixed(o-ring/front cover)here and others that were due to component wear(oil pump, pressure regulator, oil control spring).
Basically I have given up with my pressure problem and thought maybe some gurus like Ted, Aaron or any one else with some experience could figure this problem out.
Here it is, after my THIRD front cover install and oil component/s replacement my pressure via a mechanical gauge was reading very close to stock pressures. 20-25psi @ idle and 55-60 psi above idle. This was when the car was parked and in nuetral just revving to get pressure variations. BUT when I apply a load(driving) the pressure reads only a little above 30, I figure probably 40ish because of the factory gauges are so inaccurate.
When I am cruising on the freeway the pressure is 35psi when any throttle is applied BUT when I lay off the gas and pull a strong vaccum(-22) the pressre reading goes up to about 55 on the stock gauge. ????? Any time I lay off the throttle when driving I get these symptoms. High pressure at vaccum while rolling and low pressure when any load is applied.
At first I thought my stock gauge was off after I did the mechanical reading while in my garage. So when I drove my car immediatly after that I thought the reading I was getting in the cabin was bullshit. But when I caught on to this wierd situation I pulled over and put the car in nuetral and started to rev it and the stock gauge read a little below 60 when at 4000 rpm. So bad gauge is out of the question.
I cant think off anything else in the oil system that would cause this. I dont know much about bearing failure but could this be pre-mature bearing failure? excessive clearance between E shaft and main bearings maybe?
I have only put 200 miles on the car with these pressure problems but am worried about the low pressure because my car is far from stock and I know the more power the more oil pressure you want( cooling factors, ect). Some mechanics have told me don't worry(MazdaTrix. WTF?) and others are saying the engine life will be shorter. I figured that so driving has been in small amounts.
STUMPED!! Any help is VERY appreciated. Thanks!!
Basically I have given up with my pressure problem and thought maybe some gurus like Ted, Aaron or any one else with some experience could figure this problem out.
Here it is, after my THIRD front cover install and oil component/s replacement my pressure via a mechanical gauge was reading very close to stock pressures. 20-25psi @ idle and 55-60 psi above idle. This was when the car was parked and in nuetral just revving to get pressure variations. BUT when I apply a load(driving) the pressure reads only a little above 30, I figure probably 40ish because of the factory gauges are so inaccurate.
When I am cruising on the freeway the pressure is 35psi when any throttle is applied BUT when I lay off the gas and pull a strong vaccum(-22) the pressre reading goes up to about 55 on the stock gauge. ????? Any time I lay off the throttle when driving I get these symptoms. High pressure at vaccum while rolling and low pressure when any load is applied.
At first I thought my stock gauge was off after I did the mechanical reading while in my garage. So when I drove my car immediatly after that I thought the reading I was getting in the cabin was bullshit. But when I caught on to this wierd situation I pulled over and put the car in nuetral and started to rev it and the stock gauge read a little below 60 when at 4000 rpm. So bad gauge is out of the question.
I cant think off anything else in the oil system that would cause this. I dont know much about bearing failure but could this be pre-mature bearing failure? excessive clearance between E shaft and main bearings maybe?
I have only put 200 miles on the car with these pressure problems but am worried about the low pressure because my car is far from stock and I know the more power the more oil pressure you want( cooling factors, ect). Some mechanics have told me don't worry(MazdaTrix. WTF?) and others are saying the engine life will be shorter. I figured that so driving has been in small amounts.
STUMPED!! Any help is VERY appreciated. Thanks!!
07-15-06, 03:16 PM
#4
well that changes a bit, unless we know exactly how it was built it could be any of a number of things such as oil cooling jet mods or crankcase ventilation changes.
like mazdatrix said i doubt it will do any damage but it does sound perplexing. personally i believe too many people force the opinion that higher oil pressure is better in these engines, in turboed engines it can cause more headaches than good.
like mazdatrix said i doubt it will do any damage but it does sound perplexing. personally i believe too many people force the opinion that higher oil pressure is better in these engines, in turboed engines it can cause more headaches than good.
07-15-06, 03:28 PM
#5
Yeah, I have heard the term "any oil pressure is better then none." 
It is just like a thorn in your side you cant get out, every time I drive the car it annoys me. I figured it might have been crank case ventilation problems so I did little experiments like no oil cap to see if any change. Ya get deperate when you run out of things to check , checked my catch can for obstructions and air flow resistance and everything was good.
Thanks for the input Karack, it is frustrating when these "quarky" problems occur. I have about 300hp right nowI plan on trying to achieve 340-350hp out of this motor with some better fuel upgrades and engine managment and was just a little cautious with all the "pressure talk" I have heard since I started working on rotaries.
I will probably blow ithe engine before this pressure problem ever hinders anything.
It is just like a thorn in your side you cant get out, every time I drive the car it annoys me. I figured it might have been crank case ventilation problems so I did little experiments like no oil cap to see if any change. Ya get deperate when you run out of things to check , checked my catch can for obstructions and air flow resistance and everything was good. Thanks for the input Karack, it is frustrating when these "quarky" problems occur. I have about 300hp right nowI plan on trying to achieve 340-350hp out of this motor with some better fuel upgrades and engine managment and was just a little cautious with all the "pressure talk" I have heard since I started working on rotaries.
I will probably blow ithe engine before this pressure problem ever hinders anything.
07-15-06, 05:27 PM
#6
it could have oil jet mods that significantly lower oil pressure especially under load, I wouldn't worry about it, I drive a semi every day that has 10PSI of oil pressure at 1000RPM and only 30PSI at the limiter! (2100rpm) And it's been like that for years as far as I know with no ill effects.
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07-15-06, 11:19 PM
#8
Opinions are like........
Why do we do engine comparisons concerning oil pressure?
The engine is a rebuild. Do you have a list of all the mods? If not, you need to discover the mods yourself with a completely disassembly and inspection.
What oil weight/brand are you using? What oil filter are you using? Do you have a temperature gauge? What parts have you already replaced?
Per my FSM, we need ~64psi @ 3000rpm using an AFTERMARKET oil pressure gauge. If you don't have it, you HAVE a problem that needs fixing.
Reference the FSM, trace the entire oil flow diagram, inspect test and clean each and every component, and FIND that issue causing the low oil pressure.
The engine is a rebuild. Do you have a list of all the mods? If not, you need to discover the mods yourself with a completely disassembly and inspection.
What oil weight/brand are you using? What oil filter are you using? Do you have a temperature gauge? What parts have you already replaced?
Per my FSM, we need ~64psi @ 3000rpm using an AFTERMARKET oil pressure gauge. If you don't have it, you HAVE a problem that needs fixing.
Reference the FSM, trace the entire oil flow diagram, inspect test and clean each and every component, and FIND that issue causing the low oil pressure.
07-16-06, 01:02 AM
#9
Dude, I have went thourgh everything in the factory service manual. Only thing I havn't replaced and inspected is the eccentric shaft. Been dealing with this problem for 3 months and have done many tear downs on front cover and oil pan and measured all specs. Replaced the oil pressure regulator, measured the spring length on the oil control valve and replaced that(was actually out of limit). o-ring fix was finally completed after a custom combo with the teflon ring and RTV, replaced the oil pump with a new unit, oil cooler lines and unit perfect including it's own bypass pellet set-up. Shaft pellet was replaced and later shimmed. Running 20w-50.
Read my first post, I am getting very close reading to what the FSM states but that is at a stand still. Under load it is half that. My mods
Sorry man but I dont have the budget to just tear apart my entire engine to fix a problem that some find OK and others dont concur, I honestly believe it will be find. Only reason I posted this thread was to see if someone else had this problem and had pre-mature engine failure to low pressure. I know mods play a big factor in this question but it was general.
My mods are:
Street Ported bare block S5 13BT, Panspeed Hybrid T04B Turbo .60 AR, Racing Beat Turbo-back exhaust, Rotary Performance Underdrive Main Pulley , Blitz SBC id III Boost Controller, HKS Twin Power, Custom TID, All emissions removed, Greddy V-fin FMIC, HKS SSQV Blow off valve. 12lb lightwieght flywheel, ACT Heavy duty Clutch Kit, Stock ECU, HKS F-CON with upgraded ROM, F-CON GCC, AEM Ugeo wideband, Rotary Performance 480lbh fuel pump with custom voltage kill switch (helps with flooding), Brandnew stock 550cc injectors
Trust me man, been all over this **** in other threads. Been working on rotaries for 6 years now so I am not a complete dip ****. Thanks for your concern though.
Read my first post, I am getting very close reading to what the FSM states but that is at a stand still. Under load it is half that. My mods
Sorry man but I dont have the budget to just tear apart my entire engine to fix a problem that some find OK and others dont concur, I honestly believe it will be find. Only reason I posted this thread was to see if someone else had this problem and had pre-mature engine failure to low pressure. I know mods play a big factor in this question but it was general.
My mods are:
Street Ported bare block S5 13BT, Panspeed Hybrid T04B Turbo .60 AR, Racing Beat Turbo-back exhaust, Rotary Performance Underdrive Main Pulley , Blitz SBC id III Boost Controller, HKS Twin Power, Custom TID, All emissions removed, Greddy V-fin FMIC, HKS SSQV Blow off valve. 12lb lightwieght flywheel, ACT Heavy duty Clutch Kit, Stock ECU, HKS F-CON with upgraded ROM, F-CON GCC, AEM Ugeo wideband, Rotary Performance 480lbh fuel pump with custom voltage kill switch (helps with flooding), Brandnew stock 550cc injectors
Trust me man, been all over this **** in other threads. Been working on rotaries for 6 years now so I am not a complete dip ****. Thanks for your concern though.
07-16-06, 01:12 AM
#10
Originally Posted by deadRX7Conv
Why do we do engine comparisons concerning oil pressure?
The engine is a rebuild. Do you have a list of all the mods? If not, you need to discover the mods yourself with a completely disassembly and inspection.
What oil weight/brand are you using? What oil filter are you using? Do you have a temperature gauge? What parts have you already replaced?
Per my FSM, we need ~64psi @ 3000rpm using an AFTERMARKET oil pressure gauge. If you don't have it, you HAVE a problem that needs fixing.
Reference the FSM, trace the entire oil flow diagram, inspect test and clean each and every component, and FIND that issue causing the low oil pressure.
The engine is a rebuild. Do you have a list of all the mods? If not, you need to discover the mods yourself with a completely disassembly and inspection.
What oil weight/brand are you using? What oil filter are you using? Do you have a temperature gauge? What parts have you already replaced?
Per my FSM, we need ~64psi @ 3000rpm using an AFTERMARKET oil pressure gauge. If you don't have it, you HAVE a problem that needs fixing.
Reference the FSM, trace the entire oil flow diagram, inspect test and clean each and every component, and FIND that issue causing the low oil pressure.
whatever mr. fix it...
do you diagnose why a ACV is not working on an emissions stripped engine? i hope not.
07-16-06, 03:43 AM
#11
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wait wait wait....
You said it tested correctly in neutral, but not when it is in gear under load, and it produces the right oil pressure in high vacuum.
When you are in neutral and rev the motor over idle you produce vacuum except for the little blip of the throttle to get the revs up. Basically the throttle plates are almost shut when you hold it at 3k. It won't be a lot of vacuum, but it WILL be vacuum.
Your motor is not producing proper oil pressure under ambient pressure(0 psi) or positive pressure(boost). I could be wrong but it almost sounds like there is a check valve on backwards or some type of vacuum hose is criscrossed.
I'd consult a vacuum diagram to make sure everything is connected correctly and also check to make sure that all one way check valves are working. Hey, this is the perfect excuse to replace all your vacuum lines with silicone ones!
I could be wrong, but at least it is an idea!
You said it tested correctly in neutral, but not when it is in gear under load, and it produces the right oil pressure in high vacuum.
When you are in neutral and rev the motor over idle you produce vacuum except for the little blip of the throttle to get the revs up. Basically the throttle plates are almost shut when you hold it at 3k. It won't be a lot of vacuum, but it WILL be vacuum.
Your motor is not producing proper oil pressure under ambient pressure(0 psi) or positive pressure(boost). I could be wrong but it almost sounds like there is a check valve on backwards or some type of vacuum hose is criscrossed.
I'd consult a vacuum diagram to make sure everything is connected correctly and also check to make sure that all one way check valves are working. Hey, this is the perfect excuse to replace all your vacuum lines with silicone ones!
I could be wrong, but at least it is an idea!
07-16-06, 09:32 AM
#12
Cool, appreciate the input. I will look into it. But all emmissions are removed on my motor and really the only vac lines I have running anywhere are to the pressure sensor and to turbo components. All brand new fabric coated Volvo vac lines as well, I believe the only check valve I have is between the BOV and manifold.
07-16-06, 09:58 AM
#13
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Originally Posted by Boostmaniac
wait wait wait....
You said it tested correctly in neutral, but not when it is in gear under load, and it produces the right oil pressure in high vacuum.
When you are in neutral and rev the motor over idle you produce vacuum except for the little blip of the throttle to get the revs up. Basically the throttle plates are almost shut when you hold it at 3k. It won't be a lot of vacuum, but it WILL be vacuum.
Your motor is not producing proper oil pressure under ambient pressure(0 psi) or positive pressure(boost). I could be wrong but it almost sounds like there is a check valve on backwards or some type of vacuum hose is criscrossed.
I'd consult a vacuum diagram to make sure everything is connected correctly and also check to make sure that all one way check valves are working. Hey, this is the perfect excuse to replace all your vacuum lines with silicone ones!
I could be wrong, but at least it is an idea!
You said it tested correctly in neutral, but not when it is in gear under load, and it produces the right oil pressure in high vacuum.
When you are in neutral and rev the motor over idle you produce vacuum except for the little blip of the throttle to get the revs up. Basically the throttle plates are almost shut when you hold it at 3k. It won't be a lot of vacuum, but it WILL be vacuum.
Your motor is not producing proper oil pressure under ambient pressure(0 psi) or positive pressure(boost). I could be wrong but it almost sounds like there is a check valve on backwards or some type of vacuum hose is criscrossed.
I'd consult a vacuum diagram to make sure everything is connected correctly and also check to make sure that all one way check valves are working. Hey, this is the perfect excuse to replace all your vacuum lines with silicone ones!
I could be wrong, but at least it is an idea!
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.
07-16-06, 11:16 AM
#15
Agree with you Aaron. I talked to the previous owner about a month ago and when I bought it back in January. The engine was rebuilt by a rotary specialist in Japan because when the owner was dynoing at that shop the dyno ended up malfunctioning and making the dudes AFR 14.5 @ 1 bar and he blew his rear apex seal. The owner of the shop felt very bad and rebuilt the motor for free.
Rear housing wasn't damaged because the seal just cracked in two places. The owner of the shop, Mr. Natachi(I murdered the spelling) worked at RE Amemiya shop for 5 years and has 14 years of rebuilding experience so faulty construction is out of the question. This is all what the old owner told me and I met the dude and he seems very legit.
The prvious owner told me nothing extra ordinary was done to the oil system, so I assume Mr. Natachi missed something.
Rear housing wasn't damaged because the seal just cracked in two places. The owner of the shop, Mr. Natachi(I murdered the spelling) worked at RE Amemiya shop for 5 years and has 14 years of rebuilding experience so faulty construction is out of the question. This is all what the old owner told me and I met the dude and he seems very legit.
The prvious owner told me nothing extra ordinary was done to the oil system, so I assume Mr. Natachi missed something.
07-16-06, 11:45 AM
#16
Opinions are like........
Mr Fix it? sorry, but this isn't an emmissions or ACV issue, is it?
My vehicle doesn't have an oil pressure problem.
I didn't want to insult the thread starter with oil level. Try overfilling it by a pint or quart prior to your next oil change. I've seen incorrectly calibrated dipsticks. And, how is the condition of the oil pump pickup strainer? bent correctly? is its gasket new?
At your next oil change, take a sample and send it in for a UOA. If the UOA doesn't have excessive wear metals, then quit worrying about the oil pressure. If there is excessive wear, wait for the engine to fail and then you'll end up tearing it completely down anyway.
http://www.blackstone-labs.com/free_test_kit.html
My vehicle doesn't have an oil pressure problem.
I didn't want to insult the thread starter with oil level. Try overfilling it by a pint or quart prior to your next oil change. I've seen incorrectly calibrated dipsticks. And, how is the condition of the oil pump pickup strainer? bent correctly? is its gasket new?
At your next oil change, take a sample and send it in for a UOA. If the UOA doesn't have excessive wear metals, then quit worrying about the oil pressure. If there is excessive wear, wait for the engine to fail and then you'll end up tearing it completely down anyway.
http://www.blackstone-labs.com/free_test_kit.html
07-16-06, 12:27 PM
#17
Pick up strainer is good and I replaced the gasket. Another one of the many trouble shooting steps I tried. I have done the quart method to find a leak I had as a result of the second front cover and oil pan removal. Dip stick level indicator is correct. The car is plum full of oil. I might do the sample, I have a magnetic drain plug and a magnet around the oil filter. Last time I dropped the pan I changed the oil and ripped apart the filter to inspect for any mettalic debris but I was only on 170ish miles with that oil and I know that isn't enough run time to collect any decent amount to analyze or determine wear.
thanks for the link.
thanks for the link.
07-16-06, 12:49 PM
#19
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do you have vac hoses hooked up to the oil injectors?
you know the plastic piece thats splits the BIG vac hose off the back of the manifold ... one big one that gets divided down into 4 smaller ones for the 4 oil injectors?
i have no idea if thats related or what you have got setup, but i hear that some people leave the oil injectors open with no vac hoses for race engines ...
????
you know the plastic piece thats splits the BIG vac hose off the back of the manifold ... one big one that gets divided down into 4 smaller ones for the 4 oil injectors?
i have no idea if thats related or what you have got setup, but i hear that some people leave the oil injectors open with no vac hoses for race engines ...
????
07-16-06, 07:52 PM
#20
Oil injection system plays no part with oil pressure in the main oil system. The oil injectors are spring activated by pressure from the OPM system so the injectors could be left open, uncapped and it would have no effect on the engine.
07-17-06, 03:21 AM
#23
Haven't we ALL heard this
Originally Posted by FC3S Murray
magnetized plugs is useless anyway since it sees oil after the filter.
Actually, they are not worthless...look at the oil flow diagram...after the oil passes by the rotors/eshaft it dumps into the pan...is picked up...filtered and does it again.
I use one and there is alway a lil bit of slurry on it.
James
07-17-06, 06:51 AM
#24
Originally Posted by Wankel7
Actually, they are not worthless...look at the oil flow diagram...after the oil passes by the rotors/eshaft it dumps into the pan...is picked up...filtered and does it again.
I use one and there is alway a lil bit of slurry on it.
James
I use one and there is alway a lil bit of slurry on it.
James
07-17-06, 08:56 AM
#25
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Magnets at the filter can clog it easily.
After a rebuild, people are often amazed at the crap inside their oil including metal shavings and all kinds of nasties. Change the oil, remove the magnet, etc.
After a rebuild, people are often amazed at the crap inside their oil including metal shavings and all kinds of nasties. Change the oil, remove the magnet, etc.