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Oil Pressure Gauge Fluctuation


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#1 scott_8222

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Posted 25 February 2010 - 07:39 PM

I noticed on my 2000 Silverado 1500 5.3 that the oil pressure indicator on the dash is fluctuating. When accelerating the needle sits approx at the 3/4 mark and fluctuates slightly ahead and behind. What is this a sign of? What should the oil pressure be at?

#2 cerbomark

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Posted 25 February 2010 - 08:11 PM

dont know what your gauge looks like but it sounds normal to me. It will normally read a bit higher when cold and when under acceleration. Doesn t sound like anything to worry about if it s reading that high. 40 is about normal at idle. Some slightly higher and a tad lower are also normal. I m not to sure those guages are that accurate. I use it just to know I have oil pressure. Hope that helps.
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#3 brims

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Posted 25 February 2010 - 08:32 PM

Sounds right to me as well, it shouldn't stay the same pressure all the time.
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#4 JZ7109

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Posted 25 February 2010 - 10:40 PM

I noticed on my 2000 Silverado 1500 5.3 that the oil pressure indicator on the dash is fluctuating. When accelerating the needle sits approx at the 3/4 mark and fluctuates slightly ahead and behind. What is this a sign of? What should the oil pressure be at?



Sounds normal. The oil pump is driven directly from the crankshaft. The pressure will go up with engine RPM. Should be lowest at idle and go up from there. I wouldn't exactly call the oil pressure guage in the cluster accuate, just make sure it doesn't read 0. That would be a problem.

#5 USMdude

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Posted 25 February 2010 - 11:44 PM

I noticed on my 2000 Silverado 1500 5.3 that the oil pressure indicator on the dash is fluctuating. When accelerating the needle sits approx at the 3/4 mark and fluctuates slightly ahead and behind. What is this a sign of? What should the oil pressure be at?


hrm, depends on if its the 3/4 fully pressurized or 3/4 not-fully pressurized..... 40 - 60 is pretty normal thou...

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#6 swhitney2003

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Posted 26 February 2010 - 12:02 AM

I noticed on my 2000 Silverado 1500 5.3 that the oil pressure indicator on the dash is fluctuating. When accelerating the needle sits approx at the 3/4 mark and fluctuates slightly ahead and behind. What is this a sign of? What should the oil pressure be at?



Sounds normal. The oil pump is driven directly from the crankshaft. The pressure will go up with engine RPM. Should be lowest at idle and go up from there. I wouldn't exactly call the oil pressure guage in the cluster accuate, just make sure it doesn't read 0. That would be a problem.

Pegged at 80 is not good either. I had that issue, blew out one gallon of oil all over the ground after my oil filter seal let loose on my '98.
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#7 JZ7109

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Posted 26 February 2010 - 08:41 AM

I noticed on my 2000 Silverado 1500 5.3 that the oil pressure indicator on the dash is fluctuating. When accelerating the needle sits approx at the 3/4 mark and fluctuates slightly ahead and behind. What is this a sign of? What should the oil pressure be at?



Sounds normal. The oil pump is driven directly from the crankshaft. The pressure will go up with engine RPM. Should be lowest at idle and go up from there. I wouldn't exactly call the oil pressure guage in the cluster accuate, just make sure it doesn't read 0. That would be a problem.

Pegged at 80 is not good either. I had that issue, blew out one gallon of oil all over the ground after my oil filter seal let loose on my '98.



Errrrrrummm..........how'd that happen?

#8 swhitney2003

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Posted 26 February 2010 - 10:37 AM

I noticed on my 2000 Silverado 1500 5.3 that the oil pressure indicator on the dash is fluctuating. When accelerating the needle sits approx at the 3/4 mark and fluctuates slightly ahead and behind. What is this a sign of? What should the oil pressure be at?



Sounds normal. The oil pump is driven directly from the crankshaft. The pressure will go up with engine RPM. Should be lowest at idle and go up from there. I wouldn't exactly call the oil pressure guage in the cluster accuate, just make sure it doesn't read 0. That would be a problem.

Pegged at 80 is not good either. I had that issue, blew out one gallon of oil all over the ground after my oil filter seal let loose on my '98.



Errrrrrummm..........how'd that happen?

Long story short, had problems with the engine on cold starts. Lifters would slap loudly, oil pressure was high, and well... when the RPMs went too high pressure was too great and blew out the weakest link. I never did figure out what it was, sold the truck. I did several oil changes in a couple month's time. It would be perfectly fine for about 4-7 days after a fresh change then slowly start getting the lifter racket on start up. I got sick of dumping money into my '98, even though I loved it as it was a manual transmission. It was costing me just as much as paying for a new truck.
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#9 gabes2000

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Posted 19 April 2010 - 03:19 PM

I have a similar issue. At idle the pressure is constantly fluctuating between 40 and 60 rapidly (pulsing). It steadies under accelleration and returns at idle. Could this be a bad sending unit or another sympton?

#10 az'03Silverado

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Posted 19 April 2010 - 04:35 PM

If it goes WAY down at idle, like 5-10 or something, and then goes up to 40-60 on accelleration then you could have a worn pump. But if it's up at idle and goes up a few pounds when accellerating, I'd say you're fine.
The problem when it goes way up, like 80 or so, could be a clogged passage somewhere in the engine. We had an old '81 Buick Regal that had clogged push rod tubes and the oil px was way up all the time and the rockers made a ton of noise. We removed the valve covers. pulled the push rods to clean them. And all was OK after that.
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