My old engine was the same way... no oil pressure, but mine had the bottom end knock... I just swapped for a junkyard one for $500... now has perfect pressure and less then 50k miles...

 

well when i put the pan back on, i changed the filter obviously, and put in Castrol GTX 20w50. that did bring up my oil pressure a bit.
but im glad to hear that they do run low at times and its normal.
and the deal with this motor is it has a roller cam. my dad is pretty knowledgeable with cars, and i do trust his judegement. but his experience is more with older cars, so any advice i get here is great.
once i fix the oil leak that is coming from behind the timing chain gasket and replace the muffler i will be able to better diagnose it all...
but over the muffler you can hear a click/knock, esp when going down the highway next to the concrete barrier.
and yes i am trying to prevent a rebuild, i have only had the car two weeks and it was supposed to get me out of the money pit that i have now. i dont mind the lil bit i have put into it now, but a full rebuild is out of the question. i dont have the time currently and well its my ride to work.
thank you guys for all your input.

 

Frog. Years of experience is great. I have no idea if you have more experience than I, but I do have several years of experience as I approach 65 years of age come December. But I leave stuff like that out for it comes off as boasting. plus I've seen experienced mechanics that where worthless, I've seen in experiences mechanics that were worthless, & I have seen just the opposite.

Actually my only problem was you diagnosing my problem without the necessary information them stating the problem was what it was not. Which if you had of asked, I would have given to you the necessary information & that misinformation would not have been put out which could mislead someone.

Rifleman, Amen, that is if the customers really wants to do such a thing having been advised its not wise. As for me short cuts always cost me more in the long run in my early years, so I learned to take care of the problem the right way the 1st time. That has always saved me money in the long run & kept me from having to set on the roadside broken down in the middle of the night.

Of course there has been many sticking lifers thru the years, & there has been many different causes, & sometimes an additive like Riselone will take care of sticking lifters without doing harm to the engine if its indeed sticking lifters.

I did have concern for the low oil pressure, & he never did state & or I missed what the oil pressure was after he & his father changed the oil pump & screen. If it still dropped to nothing when warmed up at idle after changing the oil pump & dirty screen he has to have an internal problem that needs solved or he will find himself setting by the roadside with a locked up engine worse off than ever.

 

the oil pressure still runs low, highway driving is at a bout 40psi, when i slow down or am idling it is at 20, i no longer completely lose oil pressure.
can anyone tell me if there is a way to imbed a picture into a reply, i would like to show you all the horrible shape of my muffler, and why i couldnt hear the motor to diagnos my issues

 

For individual pictures like your muffler:
Use an image site like photbucket, click the image icon.
Kyle did a good basic tutorial
https://blazerforum.com/forum/forum-...ase-read-5167/

 

I stated my 1992 runs 30 pounds of oil pressure, actually when it gets to operating temp its just barely above 30, them just little below 30 at idle when its at operating temp.

I recall when it was about 6 months old the oil pressure gage all of a sudden pegged out. Carried it to the Chevy dealer where we bought it, sending unit was bad, they replaced it & all was well.

I have no idea how accurate our oil pressure gages are on our Blazers, it would not surprise me if they were off a little bit one way or the other.

Another thing, did the lifters stop knocking? If so, & your engine is running pretty smooth without any knocking or other noise coming from it you may be OK to go. I have seen motors that ran less than 20 pounds at idle that went for many miles without a problem.

Hopefully before you replace the oil pump & screen with the oil pressure getting so low it did not do no damage. Of course there is only 2 ways to know for sure, 1. Tear it down & check it out, 2. Drive it, if you have no trouble its OK.

If it was me & all seemed well I would probably do # 2.

 

thats the muffler i took off. anyone else think it was bad lol.

now back to the motor.

JustJerry, i have never driven a vehicle in my life that has had anything less than 40-60 psi for oil pressure, unless there was something wrong. when i changed the pump and filter, it brought it up just a little.
The lifters are still knocking as well. so that didnt solve the issue. as the oil pressure is still running at 20psi when im idling.

 

It sounding like you've got some internal problems that is causing the low oil pressure, & if you run this engine it will probably come to pieces on you. Sounds like you got a bum deal, that is if you paid very much for it.

Yet there is a couple of choices, 1. Rebuild that engine, 2. Buy a short or long block, 3. Buy one from a wrecking yard, 4. And of course you could junk it.

I know of several that have bought engines from a wrecking yard & did OK, & I know of a couple of people that did that nothing but nightmares.

I've put in one short block & one long block myself, plus pulled one engine getting a shop to rebuild it.

So sorry its turning out this way.

 

yeah i did pay a good amount for it, nothing horrible but considering it wasnt a "junk car", or so i thought.

ive been driving it as a daily driver for the past week, i just check the oil before i leave for work and before i leave the job. the lifters knock the whole way thought. but i have plenty of power behind it. i havent had the chance to fix the leak around the timing chain cover, that gasket is leaking. due to the idiot previous owner losing a bolt, or breaking it, to the timing chain cover, i picked one up from a junk yard and just havent had the time to take it all apart and clean it all and replace the gaskets and the bolt, or see what damage was done with teh bolt.

i will prolly change the timing chaing and gears while i have it apart. just cuz im already there.

im still kinda stupid towards newer vehicles and all the sensors and computer crap they put on them.
so i guess my next question would be about the oil pressure sending unit.

is it just a sensor that tells me how much oil pressure i have, kind of like the float in a gas tank tells you how much fuel you have? or does it tell the motor how much oil to send.
and also if it is bad, would that cause my lifters to knock????

i really do appreciate all the feed back ya'll are giving me. even if the majority of you are telling me to rebuild. or go short/long block route or pick a junk yard motor up.

the only problem is i dont have the money to pay a shop to do it, nor the time to do it myself currently. i have rebuilt motors before, but do to personal stuff i just aint got time. so any options ya'll may have that can put that off for a while would really help.

 

Some Rislone might quite the lifters down a little bit, maybe completely, I have known many that have used it with it with good results. It will not do no harm to your engine. Seems like it cost me a bit over $3.00 per quart.

I understand the time & especially the money portion, & having only one way to go.