Sir Rupert Hobo

i did both of these and i only get as high as 45 PSI on the(stock) oil press. gauge. at idle it's great! 30 psi all the time.

here's what has happend... at first it started out i was getting 5psi at idle. and couldn't get over 45 psi at 3000rpm+. i did the oil pellet mod. it stayed the same pressure wise.

today i got a new sending unit. it fixed my idle pressure and is at 30psi constantly, but i still can't get more than 45psi at any rpm.

what could be wrong?

Hollywood56

Verify the actual pressure with an aftermarket gauge.

Sir Rupert Hobo

yes, i plan was planning on doing that, but because i've wasted ~$50 on this subject already, i have no more money left to get an oil pres. gauge

seriously though, even if it's still the CRAPPY stock gauge, would it be SO crappy that it would actually have a difficult time reading 45+ PSI???

silverrotor

iTrader: (1)

I did the Pellet mod and replaced the Oil Pressure Sender Unit with a new one to no avail. The reading was consistently low. It wasn't until I resoldered the Tranny Harnesses (Yellow wire supplying the Unit) cracks that I found It to work ALL the time. It helps to get all the gunk off the contact point of the Harness with degreaser sprayed on a Q-Tip, for example. Try that.

Sir Rupert Hobo

good info, i'll try that....

WAYNE88N/A

Hey Logan, you actually got that monster started, lol...All right

After my rebuild with the pellet mod, she runs about 5 psi lower ('bout 57-58 psi), and a solid 30 at idle...With a new sender...All other oil componenets were the same as before the rebuild, so I dunno...

Silverrotor- Is that sender wire one long shot through the harness, or is there actually a splice or some crap in the harness in the engine bay (like for the capacitor on that slave cylinder)?

Sir Rupert Hobo

yeah, after i replaced ALL the hydraulics, she can start now

also, i always use 10w30 and i change my oil/filter like every 1000 miles just for the hell of it.

RETed

Come on, you gotta be kidding me???
You're throwing parts at it when you didn't do proper diagnostics?

This is just about as useful as trying to rebuild the motor cause you didn't know what was wrong in the first place.

Please, you won't be getting my pity.

VERIFYING the oil pressure BEFORE you started replacing parts is STEP ONE.

We can't help you if you're crying you ran out of money.

You could've easily "borrowed" a pressure gauge from a shop locally???


-Ted

Sir Rupert Hobo

ted, i'm not crying... that was a joke and i don't need your pity. oviously if you read my post i said that changing the sender helped my idle issue.

problem #1 solved.

i was going to do the pellet mod anyways, cost me less than $1.00. why not do this now?

i don't see your point. the gauge is somewhat accurate. i'm not just throwing parts at it. it needed to be done in the first place.

RETed

I thought the main question of your post was to solve the supposed "low oil pressure problem".

Changing the sender has nothing to do with your idle.
You touched something else in the process.

The gauge is only as accurate as the sensor and wiring.
The car is almost 20 years old.
Did you change the wiring harnss with a brand new one too?

It looks like you don't need any advice, since you think you're solving your problem(s) correctly.


-Ted

Sir Rupert Hobo

advice is always welcome ted. all i know is that i messed with the oil pellet and it didn't help my idle, i changed my sender, idle fixed. i have NO idea what controls the idle pressure. the gauge clip was connected to the sender all the time.

i just can't see why it won't go above 45... i was thinking something might be bad internally, how would i know? no, i didn't change the harness. maybe i should clean it up like someone said in this thread.... hey thanks for the ADVICE!

s5spd

You might have bad side seals. Does it smoke at all over 5k rpm?

Radial GT

iTrader: (16)

It is the oil pressure regulator's spring that is getting weak. It's on the bottom of the block on the rear cast iron. It is that valve that either must be replaced from Racing Beat, or Mazda. Very simple. Unless it smokes, than of course you should know what is wrong with it. Happy trails

Wizz

I did the pellet mod on my N/A after a rebuild. I'm getting a lower (than before rebuild) psi above idle and a solid 30 at idle as well. Car is still running. (20K miles later)

silverrotor

iTrader: (1)

WAYNE88N/A, If I'm not mistaken, It Is a continous wire that ends at a Harness Plug some where underneath the Main Relay by the Trailing Coil Pack, mutually exclusive from the Resistor. Someone correct the latter point If need be.

Sir Rupert Hobo

nope, no smoking at all. she feels great really.

WAYNE88N/A

Hmm, according to the wiring schematics, that capacitor wiring splices in to the sender wire before it ever gets to that plug near the main relay. I was just hoping you knew exactly where this splice occurs, in case I have to track it down one of these days. It's probably right around the area the cap wire enters the harness, I would think, but Mazda did some funky wiring runs on our cars (like running the air bypass relay ground across the engine compartment before finally grounding it, when there's a perfectly good grounding point 6" from the relay), so I dunno...

Logan- are you using a different type of oil filter from the one that was used before? Did you check the pressure regulator before you installed it?

trochoid

iTrader: (6)

And no one has questioned his use of 10w30 oil in the Texas heat?

Sir Rupert Hobo

wayne, i'm using the same kind of oil filter i have always used STP. and the regulator seemed fine to me(the new one that is).

also, i forgot about the weight issue. i should switch to something heavier, like 20W-50?

WAYNE88N/A

Sure, you could try it, but I don't think that's gonna make up a 15 psi pressure difference...

How bad were your main & rotor bearings when you put her back together?

Sir Rupert Hobo

i'm not sure, the previous owner(mechanic) rebuilt it.