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2007 Av low oil pressure fixed on a 5.3L

wrpfctr7

Full Member
Joined
Jun 29, 2006
Messages
87
Location
Southwest Chicago burbs
I finally had a decent weekend of good weather, so I was able to tackle the problem of low oil pressure.  During normal driving, the oil pressure gauge would be in a range of 12-15 psi and at a stop light or at idle, it would drop down to 0 and I would get the dreaded "Low Oil Pressure" indicator and annoying chime.  I also had a bad lifter tick that was really loud and annoying.  Well after eliminating other issues (such as bad gauge, bad oil pressure switch, etc) I researched and found that my problems could be a bad O ring on the oil pickup tube inside the oil pan.  I dont have any pics of the job that I completed, but you can find various videos on YouTube that shows you how to complete the job.  However, here are a few tips that I discovered by doing the job myself.

Make sure you wear safety glasses because there is a LOT of crud under the truck that will fall into your eyes if they are not covered.

Make sure you drain the oil before starting!

If you have 4 wheel drive, many of the vids on YouTube says that you need to remove the Transfer case altogether to be able to drop the oil pan.  That is not so!  Disconnect the transfer case from the passenger side wheel (6 bolts) and the two nuts that hold the transfer case up to the frame, (right next to where you removed the 6 bolts) and lower the transfer case down slowly.  It will hang enough that you will be able to wiggle the oil pan right past it.

Make sure you remove the 4 bolts that hold the steering rack to the frame and let the rack hang down. (There is a hole in the frame where you can get to one of the bolts)

Once you get the oil pan off, take some time to clean the inside of the oil pan!  Remove the four bolts that hold the metal plate on the inside of the oil pan.  (I used some engine degreaser to remove the last bit of oil and sludge in the bottom of the pan.

Once you remove the oil pickup tube and you see that your O ring has become somewhat of a flatten out, worn, slightly stretched out O ring, that probably was your problem.  Clean the oil pickup tube, (Make sure the screen at the bottom of the tube is ok) and replace it with a new RED O ring. (GM part # 72401)  Make sure you lubricate the new O ring with a little oil and it will slip into the oil pump better.

Make sure you put some black RTV gasket sealant on the four corners of the engine block (where the oil pan seats) because there are four small gaps (one in each corner) where the four sides of the block meet up.

I bought a new oil pan gasket (GM part # 12612350) I dont know if the old one is resuable or not.

You can put a LITTLE bit of RTV on the oil pan in a couple of spots to hold the gasket in place or use some plastic zip ties to keep it in place.  I used a couple of zip ties and snipped them off when I got the oil pan in place.

Put everything back in place in reverse order!

When torquing the oil pan bolts, keep this in mind: 
The two long bolts are 106 INCH lbs which converts to 8.8333 lbs ft.
All bolts around the pan are 18 lbs ft. I started from the oil filter side and went around counter clockwise.
The two bell housing bolts are 37 lbs ft.

After completion, I added oil and started it up.  I have no more lifter tick, low oil pressure warnings or chimes. The oil pressure gauge shows about 30-35 psi at idle and goes up to just past 40 psi (about 42 psi or so) while street driving. (About 40-45 MPH)  havnt had it on the expressway yet, looking forward to noticing what the oil pressure is at highway speeds.  No leaks or anything like that.  So hopefully that solved the problem!
Btw, I have a 2007 5.3L Flex Fuel 4x4 with about 180k miles.

 
Very nice write up! (y) If I may make one minor correction (after having done the same with my 0:cool:, what you were describing as having to move the "transfer case" is actually the front differential/axle housing. The transfer case is located to the rear of the transmission, and has a u-joint and drive shaft going to the front axle, and a u-joint and drive shaft going to the rear axle.

In general, this job takes time, but is not really too difficult in my opinion. Thanks for the write up!

-Avyfanatic
 
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