how to diagnose 5.3 low oil pressure

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
how to diagnose 5.3 low oil pressure



when cranking her up (she has 155K miles) it runs then the low oil preasure-turn off engine came on after a few minutes.

During the stuck in mud episode (3-4 minutes of burning down the tires to get her unstuck) is when I first observed (edit 2nd time the 1st time was on her initial 200 mile trip turned out to be 2 quarts low this was about 1K miles ago so I haven’t sean this turn off engine since untill now) turn off engine checked oil it was 2 quarts low added 2 quarts so I know I have the required 6.5 quarts.



during the burn down of tires I screwed up again accidently buying the wrong oil stuff was desil engine oil maybe the extra thickness of added 2 quarts of desil oil is falsely displaying turn of engine?
I have since drained plan to refill today w/ correct 5w30 regular oil.



I haven’t driven her after crank up to see if pressure would increase. (still not sure about if the new fan clugh is tight) I let it run for about 3-4 minutes then the turn of engine comes on.

I hope I don’t have to remove the oil pump front engine cover to check relief valve or pump itself.if I have to please recommend a flywheel lock tool, last time I took a cover off I broke several screw drivers trying to lock FW.



Additionally:the radiator cross support bar was laid just in front of cowl and I lowered the hood not closed just lowered to 1st click. Is it possible this bar crusted or damage the oil pressure sensor? I know on LS1 this sensor is located at back of intake kindof tucked down.

Lastly: can the oil pan be lowered enough for oil pump pick up tubes O ring to be swapped w/out removing front diff. CV axels & suspension?

I’m not a fan of the numberless guage so I’m assuming straight up 12oclock is normal 40psi at idle 1oclock is 60 psi normal.next crank up Ill observe these needle positions.if I remember correctly the needle was point to 10 oclock.

Thanks for advice
 

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
edit: my last oil change 2K miles ago I never reset the oil counter of engine revolutions so I have been seeing the change oil display

I knew I have fresh oil so didn't pay attention to the rest oil. could the the engine think the oil is worn out?

plan to inspect the tiny oil filter under the oil pressure sensor
are these normally replaced or can they be cleaned w/ brake clean.

I never done a engine flush maybe it's time to try.

dam these F offs from gm what the hell are they thinking of .
 
Last edited:

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
plan to inspect the tiny oil filter under the oil pressure sensor
are these normally replaced or can they be cleaned w/ brake clean.
That would be my first place to look. It can be cleaned however could be damaged while getting it out with a pick. Trick is supposedly to use a proper sized bolt by screwing it into the filter and pulling.

I doubt very much your oil type and higher viscosity has anything to do with it. If anything, it should have brought it up, which is why I suspect that filter. If that doesn't fix it, I'd replace the sensor.
 

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
OK thanks Mooseman
so the flush won't clean the tiny fliter?
my hands are totally shredded would prefer to not shred skin.

it mite be easier for me to remove the manifold.for oil preasure sensor removal.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
it mite be easier for me to remove the manifold.for oil preasure sensor removal.

Not needed. It can be done using a sensor socket. It's actually easier on these trucks than on the full size for some odd reason. I've done both.

A flush might work but likely a waste of time and money. To be sure, you should check with an oil pressure tester to ensure you do have pressure. These engines do suffer from leaking and broken oil pickup tube seals.
 

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
Excellent advice as usual Mooseman

OK I leave manie on I thought the tool used is a big/deep well 27mm socket are you saying these a special tool to remove/install the oil pressure sender? I’m thinking the sender is taped to the tool then install w/out it dropping out of tool.



1.hows this look for oil pressure sensor I assume it's the sender then I see theres a switch also.

https://www.rockauto.com/en/moreinfo.php?pk=320055&cc=1433749&jsn=457

they even include the filter, or should I start off w/ just filter.

Edit: during the tear down when I redid the lifters I didn’t observe oil sludge.



I’ve never used a oil mechanical pressure tester have used a fuel pressure tester.

2.will have to remove the oil pressure sender to connect the tester?

3.do the auto stores rent this tester.



I’ve known about the oil pick up tubes Oring on my 99TA has been upgraded to a thicker blue oring, I actuelly swapped in this blue oring by just lowering the front of pan titled down.

I’m thinking the cv half shafts have to be removed from oil pan.



are you saying 8 years later GM is still building vehicals w/ known faulty Orings or will there be a blue one there.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
1.hows this look for oil pressure sensor I assume it's the sender then I see theres a switch also.

https://www.rockauto.com/en/moreinfo.php?pk=320055&cc=1433749&jsn=457

they even include the filter, or should I start off w/ just filter.

Edit: during the tear down when I redid the lifters I didn’t observe oil sludge.
Looks like a good deal with the filter too.

2.will have to remove the oil pressure sender to connect the tester?
Yes

3.do the auto stores rent this tester.
Maybe. Check it out

are you saying 8 years later GM is still building vehicals w/ known faulty Orings or will there be a blue one there.
Yup. That could be the problem I have now on my Avalanche. Don't really know until I get in there. I'm just gonna replace everything along with a high volume pump just to be safe. It does have 200k km and with 4.10 gear, it does spin faster while cruising so it might have some more wear.
 

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
rock auto pictures 2 parts however only one part #
they are faking, or I didn't click whats in the box never knew about this. I'd like to start off w/ the filter but apparently they don't sell it.
I'm not sure of what this under the oi pressure sender filter is called
I don't buy alot of parts. rock A recently sent me a thanks for 8 years and here's a 5% off coupon code out checkout.

so I emailed RA thris asking for in a nice way are you openly faking me w/ the filter included. the image w/ the filter there to a normal person clearly the image implies that the filter is included which I don't think it is included. rant over.

anyone here have a name for this devil part link would be great. thanks Guys and why is this site so slow ?

same answer either person could find the part
07 saab97x 5.3 filter under OPS.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Found a couple of numbers. Dorman 917143 and GM 12585328. It's called an Engine Oil Pressure Sensor filter. Had to find it using Google.
 

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
dorman has much bigger holes compared to gm.
which filter do you recommend/use?

according to amazom reviews 1800 for dorman to 400 for gm.

I order dorman, ac delco sender and the lisle tool.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
You'll be fine with the Dorman.
 

Sprung Monkey

Original poster
Member
Oct 12, 2017
350
Al
I started draining engine oil last friday when about 4 quarts came out the flow slowed and kindof of blurped like almost stop burp seamed like a packect of water came out then right back to flowing dirty oil.I think she takes 6.5quarts right now she has tad over 6.new el cheapo filter.I'm thinking of a few ounces of seafoam in the crank crase.

I used SF intake manifolds and infuel tank 150 miles pior to oil change. I also ave marvins mystry fuild it can go into oil for sludge reduction.

cranked her up just ideled w/ new cooling stuff no leaks so far, consistant tempts. most importantantly didn't see the dredged irritating message low oil presure turn engine off

before I back off ramps I plan to double tie wrape the shift linkage, the first time I thought it was on well it went flying 1st time so just for cya.
 

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