my old chevy 350 oil pressure gauge is down to about 30lbs. its has 200,0000 miles. runs sweet.why low press.?

Answer 1

That's not that bad at all. I had to change the oil pump in my 01 silverado at 205,000 miles. now at 225,000 miles, it couldn't run better. Bring it to your mechanic and have him test the pressure. The gauge could be wrong as well, and not be the pump.
I honestly wouldn't sweat it though. 30 lbs is pretty good, and if it's running great, you should be ok. Now when your valves start tapping, then you need to worry lol Good luck!

Answer 2

This seems to be a totally acceptable reading. Oil warning lights will not come on until about 10 psi. If you have 30 psi at idle I would say that's too high. At a very high rev, this might be a little low, but it is an old motor and some of the bearing clearances will be getting bigger thus lowering pressures.

Answer 3

30 pounds of oil pressure is not a low reading. This is what you would see on a new engine. The rule of thumb is 10 pounds for every 1,000 RPM's is acceptable. If it had a high pressure oil pump in it and it has fell to 30 pounds, I would say your bearings need changed, and a new oil pump is needed to get it back up to par.
Glad to help you, Good Luck!!!

Answer 4

The best way is to change to a nice pump. One that has been blueprinted. In other words, it has been gone through and all of the parts and tolerances checked to make sure they are what they are supposed to be. Don't get a high volume pump, that will just increase the amount of oil it is pushing and won't necessarily increase pressure. They quick way is to remove your current pump and replace the spring inside with a heavier spring. The quick and dirty way is to stretch the spring you have. Remember, you only need 10psi for every one thousand RPM in a smallblock, so you may not need to do anything. I worry more about pressures that don't cahnge much with RPM than I do about low pressures. My car idles at about 20psi in hot weather and never gets above 50 psi in hot weather, but it doesn't see 5,000RPM either.

Answer 5

You have Old Car Syndrome. Frequently older big block cars experience a drop in oil pressure with high miliage. At 30 lbs., your oil light probably stays on during idle rpms. There are additives you can find at your local auto parts store from various brands (STP, Lucas, etc) that when used will boost the pressure a bit to kick off that light.
The only other way is to tear it down and rebuild.

Answer 6

My 71 K20 has 217,00 miles - same motor - never been apart - oil change every 3000.I went to a straight 40 SAE weight - Even 50 sometimes- helped Greatly.NEVER used a multi weight in it.OK IF u stay outa the SNOW.Also has a 350 in it.ALSO I would check the pressure with a MANUEL Guage - NOT one with an Electrical sending unit.EVER think the guage or sending unit could b wrong ? (0mG) :-)

Answer 7

Only one person came close on this.

It is PROBABLY because your main and rod bearings are worn somewhat, and more oil passes through them than when it was new, which shows up as your lower pressure.

If it doesn't make any noise when you start it, the engine is still tight enough to run.
But if you start to hear anything like a knock when you start it you need to fix or replace something, probably bearings.

Answer 8

Oil pressure depends on a lot of factors: type of oil you are using, rpm's, engine wear, plugged screen on oil pump, outside temperature, etc. The best thing to check out first is what pressure range is normal for for your vehicle just to ease your mind. Thirty pounds sounds in normal range to me.

Answer 9

that's typical @ idle, especially great for 200,000. I've got a '97 w/ 180,000 reads 30-40lb when idle and 45-60lb@2000rpm. depends on engine temp. I use 10w-30@every 3000 mi. I have noticed if i use a higher viscosity oil(10w-40), it's slightly lower.

Answer 10

if by "old chevy" you mean like the 73-87 years I would think 30 is normal seeing is how its the center of the gauge.