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Discussion Starter · #1 ·
Just purchased a 2006 Saab 9-7X 5.3i with 180k back in June 2022. A new ownership development is that the “Oil Pressure Low” light comes on for a few seconds upon start up. Once the engine is running, the oil pressure seems to stay in a healthy range. I did some searching and couldn’t seem to find anything with this exact issue.

The car is still under a 3 Month/3K Mile warranty from the dealership I bought it from. I already had in there once for this last week and they replaced the oil pressure sender after saying the oil pressure was reading at an acceptable level. The light is still coming on at startup right now even after the sender replacement.

I reached back out to the dealership and they are now trying to tell me that this is normal for a 5.3 with higher miles (180k). I’m not completely buying this, as it was not happening when I first bought it a couple months back. So I’ve continued to escalate it while still under warranty.

Thoughts? Should I be worried about this?

I’m also curious if anyone else has had a similar issue with their 5.3.

Video of dash at startup is below.

 

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'05 Chevy TB EXT
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A worn oil pump pressure regulator can do this - and allows too much oil to return to the pan at hot shutdown ... or it momentarily sticks and doesn't allow pressure to rise quickly ... usually not until it gets into it's correct position - on the seat holding back the pumps discharge.

What happens is that it takes a few moments to fill all the passageways and until that happen there is very little oil flow and pressure.

I have experienced this same problem in a few marine diesel application and once or twice in the old Ford Y-Block engines with their pump regulators doing the same thing.

Hopefully, I am wrong here because this is extremely hard to prove - especially to a dealer who is not want to spend labor or suffer negative cash flow.
 

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Trailblazer 2008 LTZ (4.2L) (Destroed) :(( Now Trailblazer SS (2006) AWD
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Rav is right. It could be a worn pressure regulator.
Make them do it while there is a guarantee.
Carry out an oil pressure test.
Follow specification.
(RPO LH6 VIN M)
Oil Pressure - Minimum - Hot
41 kPa (6psi) at 1,000 engine RPM
124 kPa (18psi) at 2,000 engine RPM
165 kPa at (24psi) 4,000 engine RPM

Do you have codes?
P0521 (Engine Oil Pressure Sensor Performance),
P0522 (Engine Oil Pressure Sensor Circuit Low Voltage)

Engine Oil Pressure (EOP) Sensor (5.3L & 6.0L)
(not to be confused with 4.2L Engine)
 

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Discussion Starter · #4 ·
Thanks for the advice! I’ll have to do some research into the oil pump pressure regulator replacement.

No active CEL’s, but I can scan and see if anything is hiding below the surface.

I plan to keep pestering the dealership until they stop pretending this is normal.
 

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'05 Chevy TB EXT
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I just replaced the pressure regulator on my wife's 2005 K1500 Silverado truck with a 5.3LS engine ... but it's INSIDE the pump and cannot be independently replaced --- read on >>>>

She had lost oil pressure and it's a very common problem with that engine --- and I'm not 100% sure that the 5.3s in the TBs and Voys and such are the same -- but somehow I think they are at least cousins.

Lessee --- I've got a video here somewhere .... but I just looked up the correct pump for your Saab, and it's slightly different, but the parts inside are the same and have the same function.

So - even though this video is of the 5.3LS, I have learned that YOUR 5.3L is almost an obverse version of the pump in the video .....
what you're gonna see is that the pressure regulator is integral to the pump itself and cannot be trusted if you clean or hone or lap it in because the properties on the regulator are also incumbent upon the condition of the pump housing itself.​
Here's a pix of your pump:
Bicycle part Rim Nickel Bicycle drivetrain part Auto part


.... and as you can see when you view the video, it'll be almost a mirror image of the one I changed .....​
...... therefor --- you need to change the whole piece because the regulator is in it ....​
I clipped this video so you can see the bypass-pressure regulator where I think your problem exists ....​
...... and here's another video of the insides of the pump --- just for educational purposes ...​
 

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You can also check the wiring conditions for this sensor. (although I don't think it's a wiring problem, more like a worn pump regulator)
For this
1. Turn off the ignition
2. Disconnect the negative battery cable
3. Disconnect the EOP sensor
4. Measure the resistance between the EOP sensor low reference circuit and a good ground.
If you see that the measured resistance is less than 5 ohms Inspect the EOP sensor harness connector for poor connections.
If the measured voltage is greater than 5 ohms, check the low reference circuit of the EOP sensor for a high resistance or an open.
I gave the pinout of the connector above.
 

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Discussion Starter · #8 ·
I did finally get the dealership to admit this was not a normal condition, so I dropped the Saab back off at the shop to be looked at again. Just got a call from the shop. They are leaning towards the pickup tube o-ring or the oil pump itself. They are working with the warranty company now on getting the claim approved.

I’ve got my fingers crossed that this warranty claim is accepted, otherwise I’ll be tearing this apart myself.

Thanks again for all the helpful information so far! This will come in very handy if I end up getting my hands dirty here.
 

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That o-ring can be a problem ---- and it can cause a lot of trouble. Many people thought it would turn out to be the sole problem for me - it wasn't.

I --- OTOH --- didn't find it so on my wife's 5.3LS engine; it was supple and firm - not squashed nor malformed.

It was totally the pressure bypass/regulator.
If they opt for a new pump (they should) offer to pay the difference for a Melling High Volume pump and stay away from the stock one.
 

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Rav, I want to ask you if you have experienced a malfunction of valve 455 (Valve, oil press rlf) which is located in the oil pipe (447) and is part of the oil pan (400).
Or such a breakdown is extremely unlikely.
Font Parallel Slope Triangle Diagram
 

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I've never seen #455 unless it's a bypass in case the pickup gets clogged up and it will allow oil to at least make it into the pump without going through the pickup strainer.

Wait a minute --- even that doesn't make sense to me.

Number 455 might also be a one-way check valve to keep oil in the pickup tube --- which is quite long ...... but then again, maybe not! I'm so confused!

The real regulator is in parts number 414, 415, 416 inside the housing part number 413 ... this I KNOW fer sure!

Pinch-squeezing this picture bigger, it kinda looks like another oil pump!!!

Wot? ... and looking into the top of the block it looks like a Variable Displacement engine or one of those engines that shuts off pairs of cylinders to conserve fuel ... that's not something I'm acquainted with, and thanks be that I didn't buy one of those pieces of junk.

Strange-o, strange-o.
 

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I understand, thanks Rav.
Based on the description, the bypass is item 436 (GM P/N 25014051) Here are some pictures for better understanding.
Gas Motor vehicle Bumper Auto part Trunk


Household hardware Gas Cylinder Office equipment Nickel
 

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That's definitely a DOD oil pan and pressure bypass device for the lifters to selectively let them bleed down --- or hold them open --- of which I am not sure, as I stay away from these things like Covid!

Bumper Trunk Automotive exterior Gas Motor vehicle


That BLUE O-RING is a usual troublemaker on these engines --- mY wife's 5.3LS was OK there - but there are horror stories of it failing and grenading the whole engine.

Low oil pressure at ANY time or moment HAS to be investigated --- thoroughly!
 

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That BLUE O-RING is a usual troublemaker on these engines --- mY wife's 5.3LS was OK there - but there are horror stories of it failing and grenading the whole engine.
Low oil pressure at ANY time or moment HAS to be investigated --- thoroughly!
Yes, I know about the problem with this oring. You are right the problem of low oil pressure should be carefully investigated and what the Topic Starter dealer said that this is normal when starting the engine is complete nonsense. It should not be. I hope he publishes how this story ended.
 

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Discussion Starter · #15 ·
Yes, I know about the problem with this oring. You are right the problem of low oil pressure should be carefully investigated and what the Topic Starter dealer said that this is normal when starting the engine is complete nonsense. It should not be. I hope he publishes how this story ended.
I’m still waiting for a response back from the shop regarding the warranty claim. That being said, I do feel a lot better about where the Saab is at the moment.

I had originally taken it back to the selling dealership that provided the 3month/3K warranty with purchase. They were the ones that initially tried to say that this condition was normal for a higher mileage engine. The Saab is now at a 3rd Party repair shop that still meets the terms of the warranty. So I have a lot more faith that this will be addressed appropriately.

I will for sure report back once this situation has a resolution. Thanks again for all the detailed background on this issue! I’m very happy to have found a forum with this much knowledge on the platform.
 

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Discussion Starter · #16 ·
Just got an update from the shop. Warranty company has accepted the claim, so the oil pump replacement will be covered up to $2000. Book hours on this is 17 hours, so I’ll owe a little out of pocket in addition to the $2k. Still feeling pretty good about the outcome though.
 

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Discussion Starter · #17 ·
Saab is back in my possession after pickup tube o-ring and oil pump replacement. Engine is building oil pressure MUCH quicker now. Warranty company did end up paying out the full $2000 towards the repair bill, so I am quite happy with how things played out.

 

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Hmmmmmmmm ... that's interesting!

I know the actual oil pressure and the indicated oil pressure are not tracing each other. Whatever you see on the gauge is a pipe dream by the programmers at GM to amuse the driver --- insomuch so that it now appears to build pressure faster/higher/better t'is a conundrum.
 
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