Ok, so last week my parents bought me a 1999 Chevy Blazer, 2WD, 2 Door with a 4.3 V6. Unfortuneately it was an as is sale.

My problem is this.
After a while of driving it around that day, I noticed the oil pressure was low, and would drop entirely when i came to a stop at a light or sign, and the lifters are knocking as well.

So me and my dad changed the oil pump and oil pan gasket as to that was the easiest route and possible fix(at least we thought so). The screen was pretty clogged so we thought we had it fixed.

I also found out that the motor may have been swapped to an older model S10 motor. The oil pan gasket for the 99 model didnt even come close to working but the guy at the parts store looked it up and found one that worked. A '93 S10 is what worked.

After it was all put back together, oil pressure is still low(right around 20-30 while driving) but it doesnt drop entirely. And the lifters are still knocking.

So now the only thing i can see to do, unless someone has a better idea, is to replace the Cam Shaft to get my oil pressure back up to something more normal. But the Cam Shafts are different for those 2 separate year models.

I know my best bet would be to get the VIN off of the motor. Can anyone give me a hint on where to look exactly on a Blazer, or if i can have a computer plugged up to it and it tell me or find it physically on the engine block.

Sorry for such a long post. Any help or advice will be greatly appreciated

 

The ID number is on a pad, on the passenger side front, where the heads bolt on directly above the water pump connection, to the block. For the Casting Number you have to be an ant or take the engine out. The casting number could be critical tho in determining the exact block your dealing with..hope this helps....

 

Why the Camshaft?
It's the camshaft bearings that would reduce pressure in the lifter area, not the cam itself.
And if the cam bearings are gone you have bigger problems.
While you had the pan off did you pull a {non-thrust} main bearing cap and plastigage it?

Here's my advice based on actual experience. Run an oil mix of mostly Mobil1 50w oil. I bought a car that had its bearings trashed by coolant. didnt realize till I changed oil and found it had been filled with axle lube.

With 10w-30 it had almost no oil pressure and sounded like the pistons were trying get out. With 50w in there it went back to about normal.

And the lifters quit tapping, part of that was they were dirty part because of low oil pressure. The mobil 1 fixed both probs.

I never did pull that pan and drove the car 50 kmile like that. Till it was wrecked

 

Rislone is the best oil additive for quitting noisy lifter.

My 92 had lifters start sticking, I changed my oil replacing 1 quart of oil with 1 quart of Rislone. In less that 300 miles they stopped sticking. Them at 350 miles I change my oil & filter once more, replacing 1/2 quart of oil with 1/2 quart of Rislone at every oil change.

30 pounds of oil pressure is OK, that is all my 92 S-10 Blazer 4.3 has ever held since I bought it brand new in early 92, except for when the sending unit messed up at about 25,000 miles & it was showing about 60 pounds of oil pressure. I might add it still holds that 30 pounds of oil pressure. I run 5W 30 Penn.

 

Rislone WILL fix the long term effect of running peensoyl.. but

The best additive for noisy lifter is an oil that doesnt allow it in the first place. And cleans everything up by itself.

I told you what I did...50w Mobil1.. it worked. Up to you. AGAIN.. nothing to lose, right? That or a rebuild.

 

50W oil may well bring the oil pressure up, but you may not get proper lubrication to all parts of you engine, if that happens your engine will fail, & you will be worse off than ever.

Just go to any reputable Chevy dealership & ask their service man about putting heavy weight oil into your engine.

 

Before diagnosing a problem you first need all information about it. I notice some try to do so without all necessary information, it just shows their lack of knowledge of engines plus they're more than likely to come to the wrong conclusion as you have with my sticking lifters.

The very same Penn 5W 30 has been run in my Blazers since I bought it new. I do not recall the actual mileage when I had lifters sticking, somewhere about 139,000.

Bt I do recall I had just has my oil change & had driven home. The next time I started it, lifters were sticking. Its quite easy to figure out the cause with this knowledge, the quick lube put the wrong oil in. What kind, never will know, of course they said we put the proper oil in.

With the lifter sticking, I killed it, went and bought 10 quarts of oil, 2 oil filters, along with 2 quarts of Rislone. Them did as I describe in a post above.

Penn 5W 30 is very good oil & does not cause engine troubles, as long as you have your oil changed properly. Any oil will cause trouble if you do not change it our properly. And if you use the wrong oil it will also lead to engine trouble, no matter how often you may have it change. And there is no need for 50W oil in any of today's engines, they are not designed for it, and likely it will cause trouble, even engine failure.

If you had asked me the necessary information needed to diagnose my sticking lifters I would have gladly given it. My post under this topic was not about diagnosing my sticking lifter, but about helping the one that started this topic without giving him information that might cause him to have even more & worse engine troubles.

 

????
{dupe delete}

 

Gimme a break!!! That would refer to an engine with normal wear. and I would agree in that case .. I told SPECIFICALLY what I did in the same circumstance.. what did YOU do when you had all pistons drumming and low oil pressure?

If you havent had the same situation, then I dont want to hear 'conventional wisdom'.
Bottom line YOUR advice is to rebuild it, right?

I'm pretty sure I have enough experience with various oils and additives over 45 years of curiosity on it to make my statements.
Your opinion may vary.. the broad consensus of those who actually have looked inside over long periods of time will bear me out.

whatever.. back to the OP. He can try it or not.

Let's see. Try filling it with Mobil1 50W.. maybe mixed 4 of those to 1 M1 5w30. And if that doesnt work, rebuild it...
Advance has 20w 50 at 9.99
May be less if you look for on-line Advance coupons.
or....

Rebuild it.

 

Maybe you should try a can of Engine Restorer from advance auto, just remember to shake well for 1 minute before pouring it into your engine, HA HA just kidding!! But seriously you could roll in new main bearings first and see what that does for your oil pressure for now, because it sounds like you are trying to hold off on a rebuild and new mains will give you more time, 1 rule of thumb is your cam bearings have half the amount of revolutions then your crank bearings. In other words if your crank has turned 3 million revolutions so far then your cam has turned 1.5 million. I have freshened up older engines by doing this to customer's request to save on parts and labor several times on gas and diesel engines.

good luck