I just pick up a 2003 S-10 LS 4x4 p/u, 4.3 with 48,000 miles on it (True I did the car fax). My concern is oil pressure. I took it for a little run today about 35 miles round trip going down I-10 at posted speed 75mph. No over heating problems (Never 210 on the gauge) but my oil pressure started at around 2 ticks above 40 psi and by the time I got home it was at 40psi and when I came to a stop it drop to around 20-25psi. I have notice that the intake has been taken off and some work done (Unknown work) and the Power stearring pump replace. All the fuilds have been change and are clear what kind of oil is a unknown also...

I use to have a 2000 Blazer LT 4x4 4.3 with 106K on it and battled elect problems to the point I gave up and got rid of it...but never any oil pressure problems always ran around 50psi runnning and 35-40 at a idle and that was with 5-30 oil.

My concern is the oil pressure in the 2003 S-10, since it kept dropping while running two ticks past 40 to 40 even makes me think rod bearings.
(Have had that same problem with cars before) and its a little scary to say the least as I have a VA appoinment in Tucson, AZ 71 miles from my house one way...I plan on changing the oil and filter first since I have no idea what they use and see what happens. Other then that it appear to run out okay, I even turn the A/C on to see if that would effect the heat of the engine...good there, but when I pull the dip stick out to check the oil smoke came out of the tube the stick goes in....That spells HOT oil, but why? It was I think about a quart low...since its been change hard to see the mark on the stick...

 

*Moved the above post to a thread of it's own*

If I remember correctly, GM's requirements for oil pressure are a minimum of 8psi at idle and around 10psi for every 1000rpm past idle up to a max regulated pressure of 60psi. These pressures are for everything at operating temperature.

Your pressures do not sound too low nor would I think anything was amiss with them.

 

Thanks for the info. What about the smoke coming out of the oil dip stick when I take it out? Never seen that done and the stick is very hot.

 

PCV system is not working. Could be the overheads are plugged up with sludge, the PCV valve is inoperative, insufficient vacuum to the PCV valve, or WAAAAY too much blow by going on and the PCV system can't overcome it.

 

Who ever had the truck before me had the intake off. I can tell by the new gasket, now what they did is a I don't know also the power steering pump is a brand new one. The PCV valve looks to be new have to pop it out to really seen...If have insufficient vacuum to the PCV valve where would I look to correct it? Can the truck be trusted to go lets say 140 miles without damage to the engine?

Thanks

 

Check #1, 2 & 3 in this image. Make sure they are all clean, no sludge inside, no leaks, and vacuum is good and strong at the PCV valve with the engine at idle.





If you remove the valve from the rocker arm cover while the engine is running, you might see a faint amount of smoke coming from the PCV hole in the rocker arm cover, that's normal. If it's billowing, or blowing out, there's a problem.

 

Great will give that a go....

Thanks

 

Well, the results are in. I replace the PCV valve even though the one in it look new, also replaced most of the 7/32 hose's as they were cracked and briddle...Took it out for a run (small one) I let the truck warn up to normal heat they went out maybe a mile or two and came back shut it off pull the dip stick and the smoke came flowing out and did it for a pretty look time...Ah crap...Went up got so Sea-Foam put it in the gas, let it run at a idle for awhile took it out came back turn it off, pull the dip stick and no smoke what do ever. Going to change the oil tomorrow (Its a quart low, so figure why not) take it on another 40 mile run and see what shakes out....The Oil pressure at first was great as the engine got warmer the pressure went down but nothing to worry about and at a idle it was around 25-27lb area...Keeping my fingers crossed...Now keep in mind I did not baby it on its the test runs. It was pedal to the metal, I wanted to stress it...good thing no cops were around....hahahaha

Thanks for help.

 

Took it out again today before I change the oil and all appears to be well, there was a little smoke out of the dip stick shaft for about 2 seconds or less, but the dip stick its self felt a little tad on the hot side, not buring hot, but above what I would consider normal. Oil pressure appears to be fine running and at an idle after warm up...

Thank again for the advice.

 

Oil temp will go up when it's low. Not enough volume to be cooled through the cooler so that will give it hot spots and make the overall temp rise. you should never let it run a full quart low even if you are about to change the oil and filter.