Losing Oil Pressure Really bad

jeepin916

Active member
hey everyone i started with about 20-25 psi of oil pressure.
Now for the last 3 days its droped really bad, it seems ok when i first start it up but after i drive it a few blocks it drops to about 3psi when i come to a stop.
It doesnt seem like a bad pump.... i know with a bad pump it stays low but mine fluctuates up and down, durning hard braking it will drop to 0 and it will come back up again to about 20-25, but then when i come to a complete stop it will drop all the way to 0 again.

Has this happened to anyone? i need help with this, inspection is due in a month... and it needs an 02 sensor. dont want to drop money into the engine or exhaust, new stroker motor and full borla exhaust will be going into it end of february. and for the 300 bucks in parts i can probably buy a POS to drive to werk and back.... and probably give me more free time to work on her...
 

Most people don't realize it, but the oil filter had a bvypass valve built into the filter. This may be malfunctioning.
OR
the oil pump had a hi pressure relief valve, this too may be malfunctioning.

When you start it cold, the oil is thick, as it warms the oil thins and the psi drops. This is normal.

What is not normal is 3psi.

My old diesel school instructor taught us min oil pressure in his humble opinion = 10psi per 1000 rpm.

You're pump could be worn.

Go to your favorite neighborhood auto parts house and find
CD2 OIL DETERGENT it is in a can shaped like STP but painted differently.

Read the lable carefully as there is also a CD2 OIL TREATMENT
which is essentially an STP type additive.

The DETERGENT is in a 16oz can. dump it into your crankcase. It is simply motor oil detergent. It'll clean your lubricating system.

It'll clean the oil pump hi relief valve as well as the filter relief valve too.

This stuff is good for 2000mi



I have seen old chevys with noisey lifters. As the engine runs, my friend poured CD2 OIL DETERGENT into the crankcase.
BEFORE THE CAN WAS EMPTY the engine quieted down !!!!

UNBELIEVEABLE !!!! I have been a believer ever since !!


This stuff is made by Stewart-Warner
 
80's and 90's Ford V6s and 4cyl experience this alot because of a poor design of the screen in the oil pump pickup. It becomes clogged really easily. I found this out because I had to completely rebuild the 2.3l in a ranger pre-runner I used to have because of the same kind of thing you are experiencing. If Sillsmack's suggestion doesn't work out, you might want to just drop the pan and check it all out.
 
i was thinking that it was my screen, or pick up tube, i allready tried that oil detergent stuff, and it really didnt do anything, i also thought that it might be the pressure relief valve but everyone said that the chance that they go bad is rare,but with my luck thats whats wrong....thanks everyone, i will try to drop the pan this weekend and see whats going on
 

Your on the right track...if you have ran the detergent i would drop the pan and check the pickup tube as well as replacing the oil pressure sending unit. If after that checks out all right and still your running at low pressure replace the oil pump...or since your all ready down there might as well save your selve the hassel and replace it then.
 
i am going to check the pump out put pressure 2day does anyone know what the poressure should be? ill be taping into the sending unit with a gauge to check the running pressure.
 
With oil it should be about 20-25 at idle. I have seen older worn engine with a little less. Mine will run less when I get close to the oil change date, I have since but up my schedule a bit.

I bet your will figure it out when you check it with a gauge. Real tool are always more reliable then OEM gauges and senders. But if not oil pupms aren't much and dropping the pan isn't too hard either.

Good luck and keep us posted on the out come.
 

20-25 at the soil pressure sending unit? why does it show about 40 on the dash then? shouldnt it be about 40 at the sending unit under the hood? my jeep is starting to confuse me hehe
 
Does anyone know anything about digital cameras?

Try replacing the OEM sending unit. When I bought my 95 Ram the sending unit was bad and as the motor would warm up the pressure would drop to 0 psi. put a new one in and havn't had a problem since.
 
a sending unit? or oil pump? i was planning on putting an oil pump in it but its not gunna be registered that much longer.... its engine and axle swap time....
 

Drop the pan and look for metal. A few years ago I had the same problem - driving to work on the interstate, stopped at a light, and my oil pressure dropped to nothing. To get any pressure at all, I had to keep the RPM's up around 1500. When I pulled the pan, the pick-up was clogged with metal chips and they were also in the pan. Turns out I had lost the cam bearings. If your engine is high mileage, this could be it. Also remove your oil filter and cut it in half. It'll tell you what junk is getting filtered.
 
The relief springs are easy to change too, if that turns out to be the problem. There is a spring with a steel ball in there, so don't loose the ball.
It sounds like the oil level is low because when you brake the pressure drops. I'm sure that you would have checked that first though.
I think you should pull the pan and have a look see. You will probably find the problem then. If you have changed any gaskets or used RTV on the valve covers, sometimes pieces of RTV will stick to the screen on the pickup.
 
i knwo im not low on oil that was the first thing i checked but i was told that i could have bad cam bearings... the thing about that is there is no noise comming from the engine... i allready listened to it with a stethescope. i think it started happening when i switched over to synthetic oil... i think it may have messed up soem gaskets. i know i lost a distributor O ring it just dissapeared one day and i couldnt find it when i pulled the distributor. so i think it may be gaskets stuck down there. as for the metal shavings and stuff i checked that the last oil change and there was nothing in the oil filter but i will check again this change... thanks everyone
 

I was having the same problem last year, about the time for an oil change.
I changed my oil, the problem returned about 500 miles later. I have always sworn buy fram filter for the last 25yrs. I will never use anothwer one in my life nor will I recommend them. I asked a few mechanics and they all said the same thing get the fram filter off that engine before you destroy it. I purchased a cheap walmart brand, I was thinking bull@$%##&&. Well I havent lost pressure in the last 4000 miles. even in the heat of summer in traffic going to the beach(17 milees 45 min). I would check your filter for proper operation and if it is a fram take it off!!!!!
 
hmmmm i use fram also... maybe thats my problem... im gunna switch filters at the change and see what happens thanks for the info
 
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