Low oil pressure?

Check oil pressure with a mechanical gauge, if no pressure or low (below 10psi) turn off engine immediately.

Replace oil pump.

Recommended oil for all engines except diesel is 5W-30.

Always use recommended oil, higher viscosity oils can cause engine damage, especially main and cam bearings on cold startup.

no oil pressure indicated but oil was just changed. It is clean and level full. Engine runs quietly. What's up?

If there is no noise, then chances are the sending unit is bad. You can just replace it, or get a mechanical gauge to see if there is actually oil pressure. If there is no knocking or ticking from the engine, you have oil pressure.

Can you please tell me what else could cause the oil pressure to get low it's also making a tappin noise i change the oil pump and clean the screen. it's acting like it wants to cut off and the oil pressure is below 30 it's a 5,7L engine

If you hear a tapping noise, you need to confirm that the pressure is low. In some cases, the oil sending switch will send a bad signal to the gauge. Replace the switch, problem fixed. However, if you hear a ticking, that leads me to believe there is a problem with the oil pump.

You can rent an oil pressure gauge at most parts stores. It will be mechanical. Using that, you can see exactly what the pressure is.

Thanks alot

Let me know what you find. If there is ticking or knocking, I wouldn't drive it until we determine the problem.

I have a chevy silverado k 1500 1998 I step on the gas and the exhaust got louder I also had no oil pressure the engine died and it would not restart I stopped the vehicle I saw the oil coming of the oil pan.would this be a blown oil gasket? or a thrown rod?

if you have a hole in the oil pan you probably have thrown a rod, especially since you said there was no oil pressure. get a flashlight and look inside you should be able to see some damage.

My daughter recently purchased the subject pickup. Under load (pulling a trailer) and after getting hot, upon acceleration the engine knocks and at idle the oil pressure drops very low. Is this due to bad main bearings? If so, can they be replaced without removing the engine? Thanks

well unfortunately the oil pan needs to be removed and inspect the connecting rod bearings and the main bearings. these engines have problems with the intake manifold gaskets going bad and coolant getting into oil causing engine damage. realistically most likely nothing short of overhauling the engine is going to work if indeed there is bearing failure. also these flywheels have been known to crack where it bolts to crankshaft making a noise that appears to be engine bearings.

2 days ago on my way home from work I noticed a small minor tapping noise. I checked my oil everything was good, I was preparing to take it into the shop. Drove it home and on the way home the knocking (which sounds to me in the upper part of the engine) got worse and louder. Also as I come to a idle my oil light comes on and I notice my oil pressure is bottoming out. Is this an oil pump problem or do I have bigger issues?

it sounds as if your oil pump is going out the noise you were hearing is at this point only lifters rattling do not run the engine until you fix the pump as it will damage the engine

I just started getting low oil pressure on my truck. Literally yesterday. Truck runs fine there is a small oil leak after running it after a little while, usually four or five drips. I am curious as to what could be causing this. I have general idea. I am going to replace the pick up hose because it looks dry rotted and then I am going try a new sending unit on it.

It may be the oil filter as they can cause problems like this, but the age of truck may have a lot to do with it as well. It would not surprise me if bearings may be problem. Manually check pressure with a gauge.

im hoping it is some thing none costly the drips do seem to be coming from around the oil filter somewhere but not directly from it sometimes the oil pressure is fine for example i drove the truck all day yesterday with no drops in oil pressure

I had a low oil pressure gauge when I bought the truck a month ago. oil was crappy so I changed it with 10w-30 full synthetic with an a/c delco filter. now when I start it the oil pressure is at 40 and once it warms up it's between 30-30 while cruising and down to just above the red mark at idle. engine does not make noise oil level is perfect. could it be a worn pump that needs to be replaced, wearing bearings?

Check the oil pressure with a mechanical gauge if normal replace the oil pressue switch abnormal could be the oil pump and engine bearings.

I've been getting low oil pressure for about 2 weeks now. For the most part on the highway it is a little low, approw 25, but at an idle goes to almost 0 and the light comes on. In the morning it would take about 10 seconds to get any pressure. Changed the sensor for the gauge and checked with a mechanical gauge no help. Did an oil change and got pressure right away, and good pressure but that went away after an hour on the highway I got off the pressure went to about 2 but when I got into the gas it would go up . So I pulled the oil filter and the new oil was very dark and thin but the oil on the dipstick still looked new. Engine was running good when in the gas and was ideling OK.

When you used the mechanical pressure gauge, did it read low too? Also, when you changed the oil and got good pressure for a short time, did you also change the filter at that time? Have you tried an engine flush? I'm a little confused as to how the oil could be dirty when drained, but clean on the stick.

When the pressure drops to 0 or very low, do you hear any ticking or knocking in the engine? Finally, is this the original engine with 379K on it?

Let me know.

Joe

the mechanical gauge read 23, there is some tapping when low (the light is on) sometimes. When I changed the oil I did change the filter, and after got oil pressure right away, didn't have to wait about 10 seconds like before. It is the original motor and when the oil pressure drops to where the light comes on there is sometimes some tapping. The dirty oil was only in the filter.

Did 2 engine flushes and during the second as the engine built up temp the oil pressure did start to drop and went into the orange warning but during the start up of both flushes I had about 45 lbs of pressure and after about 10 mins on the second flush went to 5 lbs at an idle in park ( no tapping sound). As far as I can tell the oil and the filter look clean.

If you are holding 45psi at start up, then the bearing in the engine are still good. My concern is the ticking you get. That sounds like a lifter when the pressure gets too low. If you can, now that you have a new filter and oil, I would like you to use the mechanical pressure gauge again. If it read 23PSI on the mechanical one, that is good. Have you tried replacing the oil sending unit?

Here is something to think about. When metal gets hot, it expands. Because of that, the pressure should increase when it warms up and not drop. At this point, I feel you either have a bad sending unit or the pick up tube screen on the oil pump is partially plugged. The ticking has me concerned, but if really had 0 psi of pressure, you would hear rod and bearing knock too.

Check it out with the mechanical gauge, and you may want to replace the sending unit. It is a cheap part and easy to replace.

Let me know what you find.

Joe
PS: When you change the oil, always replace the filter too. With the detergent in the oil, basically it cleans the old filter and takes the dirt throughout the engine.

Engine problem
1992 Chevy Silverado V8 Four Wheel Drive Manual 174k miles
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my 92 chevy cant shake this oil pressure problem. I recently had a mishap that involved all my oil dumping through the filter port and running dry before I noticed and got stopped, resulting in afterwords when filter and fluid replaced, bearings where starved and filter plugged with metal shavings giving me low and eventually no oil pres. I put a new motor with 120k mls. on it in as replacement. this motor was supposed to be good in every way, but it runs with 15-20pds at about 180 degrees. my mechanic thinks it low. It makes me nervous. Is that normal for a '95 motor. My old one had 174k mls and it had around 35psi warm. What could be the issue, if supposedly its a good motor with good pump.

let me put it to you this way, my 94 chevy pick up with about 250k miles on runs at about 15psi hot and it has been that way for the last 100k that i can remember. gm says that as long as you have above 6 psi and there are no obvious engine problems that you are fine and i agree. hope this helps ease your mind.

I have a 1989 Silverado with a 350 engine with 183,000 miles. It usually had around 40 to 45 psi but recentlly dropped to 30psi and below. I have replaced both the pressure switch and the oil pump and I am still only getting 15 to 30 psi. Twice the pressure dropped to near 0 and the check guage light came on but went off after reving the engine. Any suggestions.

Could be the bearings are worn and the clearances are opening up.But I had the same problem on my 94 Z71 and I couldnt find a reason even after pulling the oil pan and checking the bearings an replacing the oil pump. So I use 10w40 and an oil stabilizer and it helped the pressure get back where I wanted it

I recently overhauled this engine.The oil pressure runs from 40-60 psi when cold but drops to 0-15 psi when @ operating temperature and at an idle.It's had new bearings,gaskets,oil pump etc.This engine had the same oil pressure problem before the overhaul. $2000.00 later and nothing has changed.I don't know what to do next. Any Ideas?

there are two plugs that can cause this they both deal with the main oil galley and are at the rear under the main bearing cap and behind a plug from the rear. You can use a ball bearing for the plug under main as that is what was done in later years. Also do not use a crappy oil filter I only recommend napa, Purolator, bosch wix and ac is ok. also test the pressure with a manual gauge prior to look for problems.

I'm not sure I follow what you are saying. Is there supposed to be a plug under the rear main bearing cap? Do I need to drop the bearing cap to find this plug?

yes sometimes they fall out or are loose but check with a manual gauge prior to do ing that as the gauge in tuck may be off.

when i start my truck i have oil pressure. but as the engine warms up the gauge reads 0 and then while ur drivin for a littel bit when u step on the gas it goes up. do u know what would cause this and how would i fix it. thank you very much

my 95 GMC had the same problem, ask yourself these questions, is the engine knocking, is there oil in the engine,if you have no oil you have no oil pressure if your engine is knocking you could be loosing compression and it is only a matter of time before the engine will fail to run. How ever my jeep read zero on the gauge but had oil and did not knock when i drove the gauge did move while driving come to find out it was a bad gauge. I hope this helps.