I've read many of the posts on low oil pressure, but I feel that my problem is a bit different. I get the "Oil Pressure Low" warning for a few seconds on the first start in the morning. This has happened now for a couple of months. The engine is a bit "noisy" for a few seconds but then quiets down. The oil pressure then stabilizes between 40 and 50 psi. I had hoped that this would go away after an oil change. It didn't. I put in a different brand of oil filter (Fram 3506 instead of AC PF46) after making sure that the check valve worked. Can this have something to do with the DOD/AFM valve lifters? Your thoughts please. In case my profile doesn't show, it's a 2005 TB EXT with the 5.3 engine and 211000+ miles. Thanks.
Oil Pressure Low at Startup
- Thread starter wedge1
- Start date
littleblazer
Member
- Jul 6, 2014
- 9,265
Also... Having some answers to these additional questions will help with the diagnosis:
(1) Are you the original Owner of the vehicle? If not… what was the approximate mileage when you made the purchase?
(2) Historically… Do you choose Synthetic Motor Oil over Organics and what brands have you been using? (Mobil1, Syntec, Amsoil?) Type (Synthetic vs. Organic) & Viscosity (5W30?)
(3) Do you ever choose the Best Quality Oil Filters over the FRAM? (K&N, Mobil1 or Amsoil)
(4) Can you be more precise in describing the actual sounds and their locations around the engine compartment? Having somebody perform a “Cold Start to Low Idle” while you are standing in front of the engine compartment and listening will help you to be more precise.
Recently, another GMT Nation member with the same High Mileage GM 5.3L engine was complaining about a horrendous racket in his valve train upon immediate “Cold Start” and during the discussion that ensued …. some very interesting answers and simple solutions came to the fore to deal with the serious problem of having clogged and blocked oil orifices in the Valve Lifters. The best part was that the solutions were possible without involving any dramatic requirement to tear the upper engine block apart to remedy the situation.
This video post ...and contributions from other GMT Nation Members might be be just what you need to know to intervene before your own High Mileage Engine makes great trouble as time goes on. Please make sure that you possess some fair to decent mechanical skills before attempting what the Video OP suggests (He is an EXCELLENT Mechanic)… because there will be some superficial disassembly of the COP (Coil On Plug) harnesses on both banks and the removal of the Valve Covers to provide the access you will need to solve the problem. This is one of those jobs that having an extra pair of hands can really help... and save you one Helluva Big Headache:
http://gmtnation.co/forums/threads/oil-pressure-drops-tapping-engine-under-load.14755/#post-480711
(1) Are you the original Owner of the vehicle? If not… what was the approximate mileage when you made the purchase?
(2) Historically… Do you choose Synthetic Motor Oil over Organics and what brands have you been using? (Mobil1, Syntec, Amsoil?) Type (Synthetic vs. Organic) & Viscosity (5W30?)
(3) Do you ever choose the Best Quality Oil Filters over the FRAM? (K&N, Mobil1 or Amsoil)
(4) Can you be more precise in describing the actual sounds and their locations around the engine compartment? Having somebody perform a “Cold Start to Low Idle” while you are standing in front of the engine compartment and listening will help you to be more precise.
Recently, another GMT Nation member with the same High Mileage GM 5.3L engine was complaining about a horrendous racket in his valve train upon immediate “Cold Start” and during the discussion that ensued …. some very interesting answers and simple solutions came to the fore to deal with the serious problem of having clogged and blocked oil orifices in the Valve Lifters. The best part was that the solutions were possible without involving any dramatic requirement to tear the upper engine block apart to remedy the situation.
This video post ...and contributions from other GMT Nation Members might be be just what you need to know to intervene before your own High Mileage Engine makes great trouble as time goes on. Please make sure that you possess some fair to decent mechanical skills before attempting what the Video OP suggests (He is an EXCELLENT Mechanic)… because there will be some superficial disassembly of the COP (Coil On Plug) harnesses on both banks and the removal of the Valve Covers to provide the access you will need to solve the problem. This is one of those jobs that having an extra pair of hands can really help... and save you one Helluva Big Headache:
http://gmtnation.co/forums/threads/oil-pressure-drops-tapping-engine-under-load.14755/#post-480711
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AtlWrk
Member
- Dec 6, 2011
- 674
The service manual refers to five causes of engine noise on start-up for the first few seconds:
1. incorrect oil filter/faulty anti-drainback valve
2. incorrect oil viscosity
3. valve lifters clogged, worn or damaged
4. worn crankshaft thrust bearing (not sure how this factors in)
5. damaged or faulty oil filter bypass valve
Another thing to consider, especially with that many miles, is the valve lifter oil filter. Its a separate little filter that sits right below the oil pressure sensor on the top back of the engine. While I'm not sure if it being clogged would result in the exact symptoms you're seeing it is a known issue with the 5.3L/DoD system.
Looks like you're on the right track.
1. incorrect oil filter/faulty anti-drainback valve
2. incorrect oil viscosity
3. valve lifters clogged, worn or damaged
4. worn crankshaft thrust bearing (not sure how this factors in)
5. damaged or faulty oil filter bypass valve
Another thing to consider, especially with that many miles, is the valve lifter oil filter. Its a separate little filter that sits right below the oil pressure sensor on the top back of the engine. While I'm not sure if it being clogged would result in the exact symptoms you're seeing it is a known issue with the 5.3L/DoD system.
Looks like you're on the right track.
Thanks for the quick responses. I'll answer in the order they are written.
The oil pressure initially goes to about 30 psi and then increases to the 40 to 50 psi range and stays there in about a minute (maybe two) and stays in that range until I shut it down.
I am the original owner of the car.
I have always used Mobil 1. When it was new, I used 5w-30 but changed to 10w-30 early on.
I have the oil changed at the dealer. They have a "Quick Lube" Franchise. They use AC filters. I changed to the Fram just to see if it made any difference. It didn't. I have the oil and filter changed when the "Oil Life" reading gets to 20%.
I opened the hood and listened while my wife started the car. The noise didn't change much as I originally thought that it did, but it did quiet down a little bit. It is a clicking noise that sounds like lifters to me from the "Good Ole Days" when hydraulic lifters were a new thing. It is not just one lifter, but several of them. It is not what I would call a tapping noise which would be louder and more pronounced.
I have always done my own wrenching until this car. I gave in to my senior citizen status and let someone else change the oil. I sometimes wonder. I will look at your video later today.
From GT, I think that I am OK on the filter and viscosity. From there on, it gets interesting. Can you give me a little more info on the valve lifter oil filter? Thanks.
The oil pressure initially goes to about 30 psi and then increases to the 40 to 50 psi range and stays there in about a minute (maybe two) and stays in that range until I shut it down.
I am the original owner of the car.
I have always used Mobil 1. When it was new, I used 5w-30 but changed to 10w-30 early on.
I have the oil changed at the dealer. They have a "Quick Lube" Franchise. They use AC filters. I changed to the Fram just to see if it made any difference. It didn't. I have the oil and filter changed when the "Oil Life" reading gets to 20%.
I opened the hood and listened while my wife started the car. The noise didn't change much as I originally thought that it did, but it did quiet down a little bit. It is a clicking noise that sounds like lifters to me from the "Good Ole Days" when hydraulic lifters were a new thing. It is not just one lifter, but several of them. It is not what I would call a tapping noise which would be louder and more pronounced.
I have always done my own wrenching until this car. I gave in to my senior citizen status and let someone else change the oil. I sometimes wonder. I will look at your video later today.
From GT, I think that I am OK on the filter and viscosity. From there on, it gets interesting. Can you give me a little more info on the valve lifter oil filter? Thanks.
Have a look at Post # 14 (The Second Video) about the Clogged Screen Issue:
http://gmtnation.co/forums/threads/oil-pressure-drops-tapping-engine-under-load.14755/#post-480711
http://gmtnation.co/forums/threads/oil-pressure-drops-tapping-engine-under-load.14755/#post-480711
Mooseman
Moderator
That is a Great Vid, @Mooseman ...! With the advent of having this Tiny Tube Screen... it occurs to me that using 10W-30 Motor Oil... even if Mobil1 is the "Oil of Choice"...is a little too high in viscosity...especially during spells of cold weather...for passing through this skinny screen thing when the Oil Change Mileage gets close to...or just past 3,000 Miles. One of the problems with the 5.3L Engine is this: Just because the people at Mobil1 know that their oil will endure close to 5,000 Miles between Oil Changes... does not make it a good idea to let the oil changes go that far when dealing with any engine that sports any "Durable, In-line Oil Galley Filter Screen" as the means for GM to solve the problem of making Hydraulic Lifters with Oiling Ports that are just too damned tiny in the first place (...think Bruce Willis, et al, John McClain's comment from "Die Hard" here..."Ten Thousand Terrorists in the World... and I've got to kill one of them with Feet Smaller than my Sister's!")
@wedge1 ....about removing the Three Torque Converter Bolts from the Flywheel as shown in the video done by "realfixesrealfast"... The reason they had to do the job as shown was because they were unable to turn the crankshaft inside the motor and rotate the Flywheel at all due to the Original Owner over-revving the engine and throwing a rod through the side of the block... locking the crankshaft solidly in place. I would not want you to think that I would advocate removing the entire body off of the SUV Chassis as the preferred way to separate the transmission from the engine under ordinary circumstances. I have used your suggested method with great success when performing the R&R of the 4L60E transmission in the TB.
@wedge1 ....about removing the Three Torque Converter Bolts from the Flywheel as shown in the video done by "realfixesrealfast"... The reason they had to do the job as shown was because they were unable to turn the crankshaft inside the motor and rotate the Flywheel at all due to the Original Owner over-revving the engine and throwing a rod through the side of the block... locking the crankshaft solidly in place. I would not want you to think that I would advocate removing the entire body off of the SUV Chassis as the preferred way to separate the transmission from the engine under ordinary circumstances. I have used your suggested method with great success when performing the R&R of the 4L60E transmission in the TB.
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C-ya
Member
- Aug 24, 2012
- 1,098
Re: the video above in @Mooseman 's post. To change the sending unit and clean the little filter, I did not disconnect any fuel lines. I had to change the sender out and about 6 months later had to change it again (part was under warranty). The second time I took it out, I pulled the screen out and checked/cleaned it.
Mooseman
Moderator
In the case of a seized engine, instead of pulling the body, I would have pulled the engine with the torque converter. Messy but manageable.
Mooseman
Moderator
C-ya
Member
- Aug 24, 2012
- 1,098
Actually pretty clean. I don't remember removing much, if anything at all, from it. Just pulled it more for curiosity's sake. The engine has some light tapping pretty much all the time. Sounds like a good ole small block to me.
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Mooseman
Moderator
Mine sounds like a sewing machine from 2500 to 3500 RPM while accelerating. Otherwise quiet and buttery smooth.
Here's how this is turning out. I took it to a mechanic yesterday. He put pressure gauges on it and ran the tests. He said that this is a normal high mileage engine. The oil pressure at idle when it is thoroughly warmed up is 25 to 30 psi. He checked the valve lifter oil filter and said that it was clean. There was no crud in it. At some point it will need a new oil pump and that will be $2500+. I need to be aware of the oil pressure to be sure that it doesn't get too low. He suggested getting rid of the Fram filter.
Mooseman
Moderator
I just thought of something regarding the oil pump. Maybe it's the bypass/pressure regulator spring that's getting weak or maybe the pickup seal is starting to leak. Here's a video that talks about it:
The shop is probably basing the estimate on actual repair instructions that say to remove the oil pan, which also requires the removal of the differential, axles and rack and pinion. It's a lot of work. I know because I've done it. This guy found a way to do it without removing the pan.
The shop is probably basing the estimate on actual repair instructions that say to remove the oil pan, which also requires the removal of the differential, axles and rack and pinion. It's a lot of work. I know because I've done it. This guy found a way to do it without removing the pan.
littleblazer
Member
- Jul 6, 2014
- 9,265
This is exactly what happened to the Sierra except the symptoms were very different. On a cold day (below 50) the engine would start and have maybe 25 psi of oil pressure. Then it would idle down and drop... and drop more... and eventually you'd get lifter noise and the low pressure light would flash and it would show maybe 5 or so psi. Once it was warmed up it never went a tick off 40. New pump new seal and cold idle pressure is in 60 range. Hot too. But pressure was lost almost all together with that problem...
DocBrown
Member
- Dec 8, 2011
- 501
Changing the oil pump on a 5.3 is a big job but $2500 seems a bit high. I'd check around if you don't want to do it yourself.
If your lifters were an issue they would have collapsed 100k miles ago.
I believe the DOD issues with the lifters are real but not as common as some believe. I can only find a few instances online where people actually had them out right fail. Most people panic and have the lifters changed before they fail. No need for that.
My Sierra started making lifter noises after starting it up sometime early last year. I switched to full synthetic oil and the noises are gone except for occasionally at startup, and then only last a few seconds. And I use a cheap generic store branded synthetic. I couldn't be happier with the results.
If your lifters were an issue they would have collapsed 100k miles ago.
I believe the DOD issues with the lifters are real but not as common as some believe. I can only find a few instances online where people actually had them out right fail. Most people panic and have the lifters changed before they fail. No need for that.
My Sierra started making lifter noises after starting it up sometime early last year. I switched to full synthetic oil and the noises are gone except for occasionally at startup, and then only last a few seconds. And I use a cheap generic store branded synthetic. I couldn't be happier with the results.
Thanks to Mooseman for posting those videos. I looked in the service manual to get a better idea of what was in there. It appears from the diagram that there is a bracket on the pickup tube about half way down its length that shares a bolt on the oil deflector a short way back into the engine. It doesn't seem that it would be possible to get the pickup tube out of the engine without removing the nut. Maybe his 6.0 is different. Did anyone else notice this?
Mooseman
Moderator
You don't take the tube out of the engine, you leave it there. That's why he said to stuff rags in the cavity to prevent shavings from falling into the engine. You grind that tab with the tube in place with the oil pump out of the way.
If ever there was a visual means of understanding why this 5.3L Engine MUST have the Oil Changed Every 3,000 Miles...and why you should NEVER use Cheap Organic Oil and Cheap FRAM Oil Filters...this video is IT!
But more importantly... The OP shows how to escape from this "Oil Mung From Hell" using Straight Transmission Fluid filled up inside a Brand New Oil Filter along with an additional replacement of once quart of Motor Oil with Transmission Fluid... to Loosen and Flush Out all of the Fuel Carbon Blow-By, The Dirt and Other Organic Crap that will eventually Collect Inside the Engine, Clog the Lifters, Collapse the Oil Filter, Lower Oil pressure and Cause Performance Problems that go on and on and on... Here you go:
But more importantly... The OP shows how to escape from this "Oil Mung From Hell" using Straight Transmission Fluid filled up inside a Brand New Oil Filter along with an additional replacement of once quart of Motor Oil with Transmission Fluid... to Loosen and Flush Out all of the Fuel Carbon Blow-By, The Dirt and Other Organic Crap that will eventually Collect Inside the Engine, Clog the Lifters, Collapse the Oil Filter, Lower Oil pressure and Cause Performance Problems that go on and on and on... Here you go:
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Mooseman
Moderator
The problem there was a lack of oil changes. Doesn't matter what type of oil or oil filter (although I agree, Fram are junk), that type of goop comes from a complete lack of oil changes. But I have never seen anything that bad.
NOTE: It would ordinarily be my express choice of Chemical De-Carbonizing Agents to be using "Berryman's B-12 Chemtool"... Unfortunately.... This Stuff is so Extremely Powerful that it might eat away at the PTFE (Poly-Tetra-Flouro-Ethylene) Oil Seals on the Crankshaft from the INSIDE... and cause Oil Leaks afterwards... So Avoid Using it.
I'll bet you could thread a Rubber Stopper on a Plastic Applicator Tube just in front of a Garden Style Pump Sprayer with a Trigger Handle and then... after filling up the Plastic Compressible Hopper Container with Liquid Seafoam, you could Hand Pump up the Pressure and induce the Plastic Tube End into the Oil Drain Port, stuffing it in there with the Rubber Stopper pushed inside as a Sealing Grommet.
Then... it would just be a matter of pulling the Trigger while manoeuvring the Handle/Plastic Applicator Tube back and forth and all around down inside there to ensure a complete spray down of Seafoam of the Bottom End, the Oil Pan Pick-Up Tube ...and generally all around the inside of the lower crankcase Rotating Assembly and Oil Pan.
Afterwards... just replace the Drain Plug... Hand Tight...and let the stuff soak inside there for around 30 Minutes or so. Last but not least... after a good, long soaking period, undo the Drain Plug and watch all that crap that has been dissolved and liquefied empty out completely down into a Drain Pan. With all that Garbage removed, this process would allow that the Latest Oil Changes would not be constantly getting re-contaminated with "Gunk-N-Junk" after each change of Oil and Filter.
This idea would also work with a Hard Rubber Stopper threaded with an extra long Thin Red Plastic Tube so that the a few can of the "Foaming Flavour of Seafoam" can be sprayed around... far and wide and well up inside the Crank Case and do just as a good a job.
View attachment 76467
I'll bet you could thread a Rubber Stopper on a Plastic Applicator Tube just in front of a Garden Style Pump Sprayer with a Trigger Handle and then... after filling up the Plastic Compressible Hopper Container with Liquid Seafoam, you could Hand Pump up the Pressure and induce the Plastic Tube End into the Oil Drain Port, stuffing it in there with the Rubber Stopper pushed inside as a Sealing Grommet.
Then... it would just be a matter of pulling the Trigger while manoeuvring the Handle/Plastic Applicator Tube back and forth and all around down inside there to ensure a complete spray down of Seafoam of the Bottom End, the Oil Pan Pick-Up Tube ...and generally all around the inside of the lower crankcase Rotating Assembly and Oil Pan.
Afterwards... just replace the Drain Plug... Hand Tight...and let the stuff soak inside there for around 30 Minutes or so. Last but not least... after a good, long soaking period, undo the Drain Plug and watch all that crap that has been dissolved and liquefied empty out completely down into a Drain Pan. With all that Garbage removed, this process would allow that the Latest Oil Changes would not be constantly getting re-contaminated with "Gunk-N-Junk" after each change of Oil and Filter.
This idea would also work with a Hard Rubber Stopper threaded with an extra long Thin Red Plastic Tube so that the a few can of the "Foaming Flavour of Seafoam" can be sprayed around... far and wide and well up inside the Crank Case and do just as a good a job.
View attachment 76467
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