For some reason my oil pressure is real low, I just changed the oil in it last week. I put castro 10w 30, I'm not to sure but I think the guy that owned it before me said he used to put 10 w 40 in it. The oil pressure is below 30 real close to the redline. I just e-mailed the guy asking him what type of oil he used to put in it and if the car ever gave him this problem. If the car was used to 10 w40 and I changed it to 30 could this be my problem? Or is it something alot bigger? Pressure goes up to about 30 when I accelerate but I still don't like it. Has anything like this ever happened to you guys? What else could it be?

 

30 PSI @ 3000 rpm is considered perfect oil pressure by GM. Now if the oil pressure drops to Zero at idle and the engine starts to make noise then worry. The slight change in oil weight should make no noticeable difference on a guage. Most likely the oil pressure sender is going bad, $14 fix.

 

Thats a bit comforting, the pressure jumps up to about 30 when I accelarte, its not redline when I idle but it is pretty freaking low. The only noise I hear under the hood is the usual. (Injectors clicking)

But it is still strange since the car used to run between 30 and 60. Why the sudden change?

How hard is it to change out the sensor deal?

 

Easy. Right at the back of the block, just beside the dizzy. Looks like a bell shaped cylinder abou1 inch long. Ratcheting box wrench (don't know size...anybody?) will have it off in a snap. Unscrew, screw in new one, attach one wire . Couldn't be easier, but a tight place to work. Make sure you put teflon tape on the new one though. Trust me!

 

i have a problem with my oil pressure also, when i'm driving and the rpms are up decently it seems ok, just around 50ish, maybe a bit lower. when my car is idling the new autogage oil pressure gauge reads almost 0! whats goin on? probley not good is it...

 

my mazda has a problem with the oil sender as well.
used to read 110psi oil pressureand guess when it started? after changing the oil before that it was 30 at idle 60psi at 2000rpms or higher just like factory specs. changed the oil from 20w-50 to 10w-30 or vise versa and it started reading at 110 psi all the time sometimes peaking well above that

now the way it reads is around 0-5psi at idle up to around 30-45 at 2000rpms and sometimes will read 0psi when driving down the freeway doing 2700rpms let of the gas hit the gas it's back up to at least 30psi


just a bad wire connection or sender though

 

another thing though I wouldn't recomend 10w-40 oil.

most ppl will prolly agree with me being it's not the greatest oil and has been known to leave nice little sludge deposits due to the heavy spead of weights and the polymers tha make that spread possible start breaking down

 

my brand new motor is 8 lbs at 750 rpm,......only at idle...then it goes up.. did anyones motor break yet, that had similar low pressure?

 

with a mechanical gauge or the stock gauge?

if using the stock gauge verify with a mechanical gauge

nice thing abuot the electric ones is they generally don't stay very accurate

this way you know if you are chasing a phatom or fixing a real problem


but 8psi is a little low IF that is what you really have

 

My GM goodwrench motor gets about 25 at idle after its been driven for hours. At cold idle it will do 40psi at 500rpm. Goes up to around 60-70 during normal driving.

This is with a autometer guage. Which I would recommend. The stock guages are junk.

 

yeah, i never had a problem with a stock gauge b4,....but anyway..... could i have missed the front oil galley plugs or the rear main 1/4 oil passage plug and still get 8lbs while it's hot at 750rpm? thanks

 

you might of missed that


BUT FIRST VERIFY with another gauge
you might be chasing a problem that isn't there
verify first and save your time

 

is the oil pressure sender the same thing as an oil pressure switch? autozone has them for 12.99 if it's the switch. which does it look like?

 

#2

 

#3

 

i think image 3 is the sender and 1 is the switch....
Now, as far as my problem goes :
Well, just finished the Vortech s/c and new motor install. For those of you who know...I was having a low oil pressure problem, especially at idle when it was warm it was about 8lbs. I just found three 1/2" plugs in my box of parts. Thanks to all of your advice, I think they are from the front oil galley behind the timing cover. Couple of questions:
Obviously, I cannot confirm this untill I pull it apart,....But I am hoping I only have to disconnect the water pump, timing cover and the crank pulley/ balancer. Is that correct? Or do i have to pull the serp acesssory brackets? and the oil pan? will the timing cover come off without pulling the pan and acessories? Also, I did a cam break-in, and with these plugs missing (if they are), the pressure did stay around 20 lbs while I did my 20 minute break-in at 2,300 rpms. I also took it for a mile or 2 drive. DO you think my bearings and everyting else is okay? It's a brand new motor. thanks -J
oh BTW rx 7 speed...i will verify with another gauge.....but I think since i found the 3 plugs,....that that is the culprit.

 

well somebody forgot to mention they found some plugs that belong in the motor

 

well, i didn't know, cause I put the plugs in after the cam was in and degreed. But I have 3 threaded plugs....i heard the front galley plugs are pressed freezeout style.

 

All 3 could be either or but #3 is the one for our cars excluding a few without a guage and its a sender.

Autozone and other parts stores dont list (sender/switch) since they figure people dont know what thier asking for in the first place, most time they dont know the difference either.


Switch= Dummy light. Sender= Guage. Easy as that.

 

what do you mean about this?

"but #3 is the one for our cars excluding a few without a guage and its a sender."

I have three galley holes behind the cam gear that I am referring to. I was planning on plugging all three.

 

he was talking about the pictures above. oil pressure sender unit.

 

ah...lol////well the good news is,....i started at 8p and it is now 4:30 am...I diagnosed it right and it was the gallley plugs..the motor sounds good and I am building good oil pressure,..however, I am afraind I already did damage with low oil pressure when I did the cam break-in, and I took it for a 2 mile easy ride. Also....I started it twice to warm it up to check the pressure with a new sender and gauge...l I HOPE ther is minimal or no damage,...but it would be my luck that this thing breaks next week cause of the missing galley plugs.... what do you guys think... i could use some good news....but tell me the truth.

 

Must have been a super high volume pump to have any oil pressure. Did you happen to slide the cam forward a tad to at least get a glance at the front cam bearing? Reguardless if it seems fine now it may be ok since you did have some oil pressure.

 

no i didn't slide the cam forward..but yeah, i do have a high vol pump....plus, when the motor was cold the cleaernces on the journals were probably tighter....so i was able to build a little pressrue before it dumped out of the galleys