Oil Pump and Lifter Issues, or something else causing this?

KevinRum · May 11, 2022

Hello Everyone! I seem to have a compounding issue with my 2014 GMC Sierra SLT 5.3L which I have been the owner since 2016. It started about 7 weeks ago with an oil pump failure code appearing often although always had oil pressure, in fact it would fluctuate between 18psi at stop light to almost 80psi when accelerating very fast. Took 3 weeks to get into mechanic and drive it carefully during this time resetting the code each time it showed up (each leg to and from work, 28miles). After mechanic connected his master gauge, he said pressure was all over the place so recommended replacing the oil pump. Once replaced, no more error codes although my pressure still fluctuated between 18psi and now buries the needle way past 80+ psi when under high load. If the gauge went to 90 or so I felt like it would still bury it. Mechanic said high pressure better than low although in the 160K miles already driven, I have never seen it reach much over 70 psi even while pulling the camper … until the 2-stage oil pump error code. This is just the beginning folks.

Not a week passed and started getting random misfire code. Since it was rainy when this occurred, we figured it was plugs or wires. Code went away on its own while on my way to the parts store (rain cleared up and now sunny), purchased and changed them anyway. No problems for few days till it snowed Easter evening. The next morning while leaving for work, misfire cylinder 5, so I turned around and quickly installed the new coil pack. This did not fix issue. Drove to work with misfire then had it towed to the mechanic so I wouldn’t complicate the issue. Problem was a collapsed lifter, intake side. Mechanic replaced all lifters. Drove less than 100 miles and misfire cylinder 5 again! Immediately towed back to the mechanic who verified exhaust lifter (new) failure. In fact, mechanic said it was destroyed. Mechanic replaced that lifter under GM parts warrantee and in less than another 100 miles, misfire cylinder 1. Just before this latest lifter failure (so I assume) I read an old code P0451.

Q: Could the P0451 have anything to do with my lifter rash and what the heck is the mechanic missing about all these failures? I really think the large change in oil pressure, even before the new pump, is key to what might be causing the lifter failures, but the mechanic keeps dismissing it. Can anyone help me understand?

Mathew Kirsch · May 16, 2022

I really can't help you on correlating the oil pressure problem with your lifter problem, but I can tell you lifter problems are a thing on these trucks.

First one happened to me in March 2020. Lifter seized, wiped out a pushrod, I mean bent it over and snapped it like a twig. The thread on it is still here.

Happened again yesterday. 141000-ish on the odometer this time. That's why I'm here.

My oil pressure is pretty stable, 25 at idle and a bit over 40 driving.

Edited May 16, 2022 by Mathew Kirsch

newdude · May 16, 2022

On 5/11/2022 at 12:21 PM, KevinRum said:

Hello Everyone! I seem to have a compounding issue with my 2014 GMC Sierra SLT 5.3L which I have been the owner since 2016. It started about 7 weeks ago with an oil pump failure code appearing often although always had oil pressure, in fact it would fluctuate between 18psi at stop light to almost 80psi when accelerating very fast. Took 3 weeks to get into mechanic and drive it carefully during this time resetting the code each time it showed up (each leg to and from work, 28miles). After mechanic connected his master gauge, he said pressure was all over the place so recommended replacing the oil pump. Once replaced, no more error codes although my pressure still fluctuated between 18psi and now buries the needle way past 80+ psi when under high load. If the gauge went to 90 or so I felt like it would still bury it. Mechanic said high pressure better than low although in the 160K miles already driven, I have never seen it reach much over 70 psi even while pulling the camper … until the 2-stage oil pump error code. This is just the beginning folks.

Not a week passed and started getting random misfire code. Since it was rainy when this occurred, we figured it was plugs or wires. Code went away on its own while on my way to the parts store (rain cleared up and now sunny), purchased and changed them anyway. No problems for few days till it snowed Easter evening. The next morning while leaving for work, misfire cylinder 5, so I turned around and quickly installed the new coil pack. This did not fix issue. Drove to work with misfire then had it towed to the mechanic so I wouldn’t complicate the issue. Problem was a collapsed lifter, intake side. Mechanic replaced all lifters. Drove less than 100 miles and misfire cylinder 5 again! Immediately towed back to the mechanic who verified exhaust lifter (new) failure. In fact, mechanic said it was destroyed. Mechanic replaced that lifter under GM parts warrantee and in less than another 100 miles, misfire cylinder 1. Just before this latest lifter failure (so I assume) I read an old code P0451.

Q: Could the P0451 have anything to do with my lifter rash and what the heck is the mechanic missing about all these failures? I really think the large change in oil pressure, even before the new pump, is key to what might be causing the lifter failures, but the mechanic keeps dismissing it. Can anyone help me understand?

Oil pump failure is somewhat common. The pressure control solenoid fails. Make sure when they did it, they also replaced the timing chain tensioner as the tensioner as those can rub a hole in the pump.

Oil pump doesn't necessarily = AFM lifter failures. AFM lifter failures is due to oil aeration, mis-timed AFM event due to an issue with the VLOM, lifter sticking in the bore or defective locking pin.

Cylinder 5 misfire. Cylinder 5 is NOT an AFM cylinder. If you had a misfire on that cylinder, you could have found a bad lifter, but you'd also more than likely find the cam bad. Also, if the shop did not replace the VLOM, they half did the repair as GM wants the VLOM replaced.

DTC P0451 is for Fuel Tank Pressure Sensor Performance. Nothing to do with your misfires.

Edited May 16, 2022 by newdude

KevinRum · May 18, 2022

Sorry, misfires on cylinder 6 and 1, not five. They said the VLOM was tested and met specifications, but not replaced. Not sure if I mentioned the oil pressure sensor was replaced early in these issues. Is the pressure control solenoid different than the pressure sensor and where is it located? I doubt the pressure control solenoid was changed but considering I have very high pressure, it would seem the 2-stage pump is kicking in ... but beyond my knowledge base. Also, the tensioner was not part of the parts RR list so doubt that was replaced either. Thank you for your help and input!

pokismoki · May 27, 2022

instead of using factory watered down oil try switching to 5w30 , 5w-40, 10w30, or 10w40 full synthetic and install lower temp thermostat. this might improve metal to metal lubrication and avoid siezure of lifters

the lower engine temp will also help the oil press sensor electronics live longer since it wont be getting roasted to death.

Edited May 27, 2022 by pokismoki

newdude · May 28, 2022

On 5/18/2022 at 12:49 PM, KevinRum said:

Sorry, misfires on cylinder 6 and 1, not five. They said the VLOM was tested and met specifications, but not replaced. Not sure if I mentioned the oil pressure sensor was replaced early in these issues. Is the pressure control solenoid different than the pressure sensor and where is it located? I doubt the pressure control solenoid was changed but considering I have very high pressure, it would seem the 2-stage pump is kicking in ... but beyond my knowledge base. Also, the tensioner was not part of the parts RR list so doubt that was replaced either. Thank you for your help and input!

GM's TSB (not a recall nor a special coverage) wants the VLOM replaced if the engine has been apart for lifter failure to eliminate it being a possible culprit. Says nothing about testing it, just says to replace it.

The oil pressure control solenoid is serviced only as a part of the oil pump, so if the truck sets a P06DD code for example, you'd replace the entire oil pump and out of safety, the timing chain tensioner as there is a bulletin on that rubbing through the oil pump.

Grumpy Bear · May 29, 2022

On 5/16/2022 at 2:15 PM, newdude said:

Oil pump doesn't necessarily = AFM lifter failures. AFM lifter failures is due to oil aeration, mis-timed AFM event due to an issue with the VLOM, lifter sticking in the bore or defective locking pin.

Isn't there also something about measurement of the affected lifter bore? (to loose)

newdude · May 31, 2022

On 5/29/2022 at 9:57 AM, Grumpy Bear said:

Isn't there also something about measurement of the affected lifter bore? (to loose)

I know there is this from Melling - Tech Bulletin on JB-7011 lifters for GM LS engines with AFM - Melling

Has a lifter bore spec, so if there was wear in the bore out of spec, that could be a problem.

KevinRum · June 1, 2022

Thank You newdude! That makes sense and great information. I will forward this to the mechanic as I am still waiting for it to be repaired for the third time. They now say the part or on backorder because there is a shortage in the area ... go figure!

F- GM · August 25

How much 2014 GMC Sierra Well let me see gm screwed the hell out of all of us because they know damn well they put out s***** faulty parts and we're just eating it I got 50,000 miles my oil pump apparently is going out according to this engine light that b******* code they're only recalling from Jan to Feb in 2014 and they're saying yeah we put out bad parts warranty runs out we're only recall a certain few f---k that that's b******* they know they f***** us look can somebody tell me if general motors is actually going to stand by their name and take care of their American people because that's why I buy gm let me tell you I don't run my truck hard it's a 2014 and I got 50,000 on it 1 pissed off disabled Viet Nam vet

Homewrecker007 · August 25

7 hours ago, F- GM said:

How much 2014 GMC Sierra Well let me see gm screwed the hell out of all of us because they know damn well they put out s***** faulty parts and we're just eating it I got 50,000 miles my oil pump apparently is going out according to this engine light that b******* code they're only recalling from Jan to Feb in 2014 and they're saying yeah we put out bad parts warranty runs out we're only recall a certain few f---k that that's b******* they know they f***** us look can somebody tell me if general motors is actually going to stand by their name and take care of their American people because that's why I buy gm let me tell you I don't run my truck hard it's a 2014 and I got 50,000 on it 1 pissed off disabled Viet Nam vet

You might try contacting corporate if you're dealer won't help. Not sure they will since you're out of warranty in year wise.