2001 GMC Yukon Logo
Cole Kraus Posted on Nov 30, 2013
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Low oil pressure/ guage fluxuates but runs low

Start Yukon the pressure will read about 40. It will "tick" in motor for a little while then "smooth out" and run good. The oil guage will be under 40 and will fluxuate upward when acceleration. Not sure if screen might be dirty or pump going bad or bad sending unit or sensor.

1 Answer

Colin Stickland

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  • GMC Master 22,516 Answers
  • Posted on Nov 30, 2013
Colin Stickland
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Joined: Nov 04, 2008
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Sounds like a valve lifter or in queens english a hydraulic tappet ,Now what i used to do on the rover V8 was to add a tin of gunk brand name exterior engine cleaner and then let customer have the car back and do some miles,or as soon as the noise stopped ,then change the oil and filter and add the diesel/petrol turbo engine oil as this is detergent and then change the oil every 5/6000 miles with a oil filter every third oil change ,if no engine cleaner then try half a litre of diesel or just change the oil for one detergent type diesel engine oil you will not hurt the engine using this oil the cheaper it is the better as well .In extreme cases i give a 2 second squirt of fairy washing up liquid to the oil as well ,has to be fairy mind them cheapos are no good for this job .Stop worring about it and just do as i say

5 Related Answers

Anonymous

  • 855 Answers
  • Posted on Oct 02, 2009

SOURCE: 03 gmc envoy with 5.3 140000 miles. Oil pressure

There may be a loose wire or the gauge or sending unit may be going bad. The first thing I would do is to hook up a temporary oil pressure gauge, not using the old one at all. With this watch gauge while driving and see what readings you get. If the readings still jump around you have a pump that is getting weak and failing, If that is the case the pump should be replaced, but with high milage you may consider rebuilding the entire engine. If the readings stay normal start checking for a loose wire at gauge or sender. Then check sender, then gauge and replace as needed.

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Anonymous

  • 59 Answers
  • Posted on Mar 01, 2010

SOURCE: low oil pressure 93 GMC P/U w/350 motor w/205,000 miles gauge

While engine is running, open the cover where you add oil to engine and see if you see a good flow of oil, if good flow, could be as easy as replacing oil sending sensor. got to realize that if poor maintenance history your engine may not be building enough pressure at iddle to move your hydraulic operated valves, only when you rev it up it will pump enough to run smooth. if running engine too long, you may cause more damage to other engine components such as crankshaft and cam shaft bearings. if you can spare a few bucks, have a good mechanic check your oil pressure with a mechanical gauge. another cheap option is to replace oil pump. last resort if you love your truck as much as we do,replace engine or rebuild it. At 205,000 this is a normal symptom, other than timing chain problems, most engines don't make it that far. hope this helps!

Anonymous

  • 74 Answers
  • Posted on Mar 16, 2010

SOURCE: Oil pressure gauge reads 40 or half pressure

on general motors engines all the way down to 15lbs of oil pressure is acceptable i prefer 30 but if the 40 you have down is the lbs of pressure your in good shape brand new engines generally only have about 45lbs of pressure

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Sam Akber

  • 1149 Answers
  • Posted on Sep 13, 2011

SOURCE: oil pressure has dropped to

Better have it looked after, and yes there is a test for oil pump pressure.

A

Anonymous

  • Posted on Nov 26, 2012

SOURCE: how can you tell if the oil pressure sensor is going bad or the oil pump is going out

Put a mechanical gauge on the motor-- to confirm
oil pressure

The electrical pressure sensor can fail & are not always
exact

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