just wanted to hear if some of you have had an engine that was just tired and had low oil pressure and was able to run the engine for some time before another rebuild by using something in a can to boost the oil pressure to allow the engine to hang in there for alittle longer.

here is my story, just bought a suburban ,it is in great shape for the age, its a 93 4x4 suburban with 350 and over drive tranny. it runs great. very little shake from the engine, power seems to be good for the weight of the truck and still gets good gas milage for what it is and it does not smoke at all. it has 275000 highway miles on it. the oil pressure at highway speeds are 20 psi or about. and at idle (not in gear) it is lower of course and you can rev it up and the pressure goes up.

now sitting at a stop light the oil pressure falls low enough for the "check gauges" light comes on and the oil pressure is in the red. and it flickers the check light on and off at times .

im sure its just from wear in the clearances of the motor and a rebuild should be in order soon.

but i would like to buy some time and see if there is a short term solution. i dont think pouring in motor honey is the solution because that just makes the oil so much thicker and harder to flow when its cold and i think i might do more harm at start up with no oil anywhere for a few ticks of the clock.

i would like to hear some opinions on this. any maybe some short term solutions in a can i might not have heard before.

i paid 1500 cash for the truck today and i think i got a deal on it even if it means a new crate motor in a year or so.

thanks in advance

Try 20W50 weight oil.

how about running Shell Rotella Diesile(SP?) 15w-40 oil, that would be thicker then 5w-30 oil but i thing thinner then a 20-50w oil and since the rotella diesel is for heavy rigs maybe it might be good enough for a tired engine and give more protection???????


thoughts on that.

try that Lucas stuff

how about running Shell Rotella Diesile(SP?) 15w-40 oil, that would be thicker then 5w-30 oil but i thing thinner then a 20-50w oil and since the rotella diesel is for heavy rigs maybe it might be good enough for a tired engine and give more protection???????


thoughts on that.

More protection for bearing surfaces probably, but less likely to help with the oil pressure problem than 20W50.

Why not just drop the pan and toss a hi pressure pump in it?

Why not just drop the pan and toss a hi pressure pump in it?
=
A hi pressure pump will not do anything to the low speed pressure,
It is the same pump with a higher pressure relief valve spring in it.
This does nothing until you get to the pressure that opens the relief.

A Hi volume pump may help a little
I would opt for a heavier oil if it were me assuming it has thin oil in it now.

ya thicker oil seem to be the way to go. but the down side is i dont know if the last owner has been doing this. as far as i know maybe this truck has the 50 wt oil in it.

i was going to drain the oil tomorrow and change filter. i did buy a can of engine restore. it was like 9 bucks at wal-mart earlier this evening. but thought i would get on the site and see what ya all thought.

im not looking for 60 psi pressure just enough pressure to keep the oil pressure out of the red while i sit at stop light at idle and not be right next to zero oil pressure.

i worry alittle about the morning start up being cold using 50w oil. do you think i would be doing more harm then good?

15-40w oil seems to be a good in the middle of the road choice what do you think?

comments on the 50 w oil?

ya thicker oil seem to be the way to go. but the down side is i dont know if the last owner has been doing this. as far as i know maybe this truck has the 50 wt oil in it.

i was going to drain the oil tomorrow and change filter. i did buy a can of engine restore. it was like 9 bucks at wal-mart earlier this evening. but thought i would get on the site and see what ya all thought.

im not looking for 60 psi pressure just enough pressure to keep the oil pressure out of the red while i sit at stop light at idle and not be right next to zero oil pressure.

i worry alittle about the morning start up being cold using 50w oil. do you think i would be doing more harm then good?

15-40w oil seems to be a good in the middle of the road choice what do you think?

comments on the 50 w oil?
=
Hard to say but if you have excessive clearance it should not hurt a thing if you warm the engine up before you get crazy with it.
Circle a lot of track guys run it all the time with no problem, I used to run it years ago in a BB but it had pretty good clearance too..
No way to answer as you don't know what it has in it now so all this is just a guess,,:)

Are you getting your pressure reading from a mechanical guage or from the factory GM electric guage? I've seen the pressure senders in those trucks go bad and produce the same symptoms. Low pressure on the factory guage and oil light illumination at idle. On one truck, I had an Autometer mechanical guage reading 40 psi. At the same time, the factory guage in the cluster was very low and the oil light was on. Replaced the sender near the oil filter, fixed.

Check the factory sending unit. We had a 92 with a 350 and it did the same thing. Bad sending unit, bad bad thing:yes:
Also you will get the same problem when the cluster is loose on the connector pins that the instrument cluster seats into.
We pulled ours, reset the pins and all of the gauges worked flawlessly thereafter.

Had a big block that idled on 5 lbs and ran on 25 lbs at 2000 rpm with 10W-40. I changed to 4 quarts 20-50 and one quart of Lucas oil stabilizer. Idle pressure increased to 18 and running pressure at 2000 increased to 40.

If it was summer I would say go with the 20-50 but I figure Kansas can get kinda cold in Jan-Feb. The 15-40 with the Lucas would be better in the winter.

I'm for dropping the pan and rolling in a set of main and rod bearings and a HV pump.

If it's not using any oil...that will get you by for a long time.

If you don't want to do that..the HV pump for sure. Heck use a big block HV pump and really outrun all the leaks!!


JIM

you didnt mention what brand oil filter you had on it. is it orange??? Go to a NAPA gold or a Wix & see if that helps

def. switch to a filter that will flow a little better, maybe a k&n
add a can of stp, prob. wont help the press. but will protect some, and thicker oil(have you changed the oil since buying it, it might have thinner syn. in it)

I too had a bad sender unit. You might want to hook a good gauge into the oil system and see what the oil pressure is for sure before tearing things apart. With overdirve, you aren't turning very many rpm to build a lot of oil pressure anyway. I'm never over 2K rpm unless I'm on a freeway.

I've run engines like this MANY, MANY miles using no more than a can of STP/Motor Honey on top of a fresh oil and filter change!

10w40 and a can of STP and go!

BUT don't blip her cold!! AND she will probably be hard to start if it get's COLD!! (But that's what Starting Ether's for USED SPARINGLY!!!!!!!!!!)..

Been there, had ta do all this crap thriough the years daily driving my old beaters.

pdq67

thanks for the many opinions, this is great to hear all of them. the bearing and oil pump sure is out of the question at this time. if i was going to tear into that far then i would just buy a crate engine.

i did not have time to change my oil today. i spent most of my time fixing the driver seat frame which was broke and replacing speakers and cleaning the carpet. took many of the seats out to clean this thing up.

i did how ever go to oreillys and buy the rotella diesel oil 15-40 wt and bought a bottle of lucas oil treatment. went back to walmart and returned that engine restore stuff in the can. i did buy a oreilly brand oil filter so at least it is not orange.

i let the truck run today for long time and the oil never got inot the red to cause the check gauges light to come on. but if i put it in gear and idle it sure would take a drop and flicker the light on and off and sometimes stay on for a few more seconds. put it back into park and it would go out( the light) and the pressure would go back up.

i'll post the results of changing oil and adding the lucas as soon as i can do that. maybe tomorrow.

thanks dennis

I agree with the guys about the electric gauge. I just had the same problem with my daughters 4.3 in her 93 S10 195,000 miles. Check gauges light coming on, engine had a knock. I'm thinking rod bearing bad. I hook up my trusty Sun oil pressure gauge. 60 psi, electric reads 30psi. replace sending unit. Now 60 on the gauge and 60 on the factory gauge. Knock was a bad flex plate. :D

Bill

And I have done no more than dingle-berry overhauled them by just installing new rod and main bearings, rings and a valve job and that was it and got years more life outta the old beater!!

Can you say?? A $150 "SHADE-TREE" overhaul job..............

pdq67

thought i would give an update on the oil change.

put in 15-40w rotella diesel oil and one bottle of lucas oil treatment. after letting the suburban idle for a few hours while working on it the oil pressure looks like it has stabilized. it still is low but at least its not in the red anymore.

if im reading the little lines right it is showing 10-12 psi oil pressure at idle and in gear it hardly moves. that with engine totally warmed up and if i raise the rpm's up to about 3000 rpms then it reads about 15- 17psi. the needle moves very little.

the goal was to get the oil pressure up high enough so the light would not flicker on and off while idle in gear, at a light, up town or where ever

i'll get a few more things done and i will check into the sending unit ordeal and see if that helps any to raise it even more.

thanks for all the opinions.

And I have done no more than dingle-berry overhauled them by just installing new rod and main bearings, rings and a valve job and that was it and got years more life outta the old beater!!

Can you say?? A $150 "SHADE-TREE" overhaul job..............

pdq67

Did you hand lap the valves? :D
I love old school ways, today they call it "ratrod", back then it was all we could afford!!!

Bill

Put a mechanical gauge on it after you remove the sending unit. That will tell you what you really have. Then if it reads higher replace the sending unit.

I've seen the pressure relief spring wear out on the oil pump. Had one that had similar symptoms you're seeing, when I finally got around to pulling the engine, inspected the pump, and the spring was about 1/4" short to even contact the pin. It was constantly bypassing.

Wix oil filter 5160R

No, usually I just have a valve job done on my heads and am done with them..

And install new valve stem seals too like the cheap black rubber umbrella jobbers.

pdq67