Oil Pressure - Am I paranoid?

[Joseph Garcia]

IMO, anything below 20 psi at hot idle is too low. I concur with the folks above to file a claim with Jasper now and follow their instructions.

 

[rdezs]

File a claim.

We can speculate all day long between the oil pickup tube o-ring, cam bearings, etc ... but if it's under warranty, wash your hands of it and exchange it.

 

[pbbigmac2]

Hopefully jasper will at least cover the labor difference for this one. Would be a bummer to pay for labor again and be without the car another 2 weeks.

some parts are re-used on a long block, I am not sure if the oil pump is one of them, or not the oil pan is for sure and I believe the oil pressure sensor is another and water pump and intake and the rest of the bolt on's, spark plugs should be new.
10 psi is the trigger for low oil pressure, technically 12 I would say is questionable, normally 14 is what you might see at hot idle.
at the very least when that 500 miles rolls around I would get a sample and send it out to blackstone labs or who ever you prefer.

Based on Jasper’s website, new oil pan comes with the long block. I know the oil pressure sensor is reused, but I replaced that with a GM sensor roughly 1 year/15k miles ago.

 

[pbbigmac2]

cold idle mines goes a little bit over 40...hot idle I would say in the 30s..

I have noticed the longer I go without changing the oil the lower the oil pressure gets as I drive. But soon as I change the oil and filter the oil pressure gets better... I usually go by the oil percentage to change my oil but others change every 3k

Cold idle was nearly 55psi today. Historically I change my oil every 5k on all my cars and run a blackstone every 20-25k or so.

 

[Foggy]

Cold idle was nearly 55psi today. Historically I change my oil every 5k on all my cars and run a blackstone every 20-25k or so.

Thats a really big difference to 10 psi hot...
I Think I'd at least report it to jasper....
And change the oil and filter... I once had a bad filter that was causing this issue
(on a different engine). It was a faulty filter.
Use an ACDelco or Wix filter. Do you use a magnetic drain plug ???
I do on all my cars and my customers' cars. It's a good indication if something
is really wrong.
The pressure sensor and/or sensor screen could also be an issue. they get
f'd up pretty quickly. Use a gm sensor if at all possible

 

[pbbigmac2]

Drove it into my ditch (not sure if enough) and added 2 quarts. Pressure went up a couple PSI.

Going to do the 500 mile oil/oil filter change with a AcDelco filter now and see if that changes anything.

If no change, picked up another GM oil pressure sensor just to rule that out.

Calling Jasper either way tomorrow morning

 

[pbbigmac2]

Filter used was a Napa proformer equivalent of a PF63. Would that cause any pressure changes since it’s a larger version of the pf48 filter?

 

[Foggy]

Filter used was a Napa proformer equivalent of a PF63. Would that cause any pressure changes since it’s a larger version of the pf48 filter?

No it wouldn't at all. Just gives a bit more filter area and oil capacity
I use the Wix 57045 on all the gmt 900 trucks/suvs... It's a better, longer filter
than the wix 57060 that the 'book' calls for .. Kinda like the diff between the 48 to 63

 

[swathdiver]

Mine was higher but acting like that before changing the o-ring. Oil pressure is normal at speed but low (for my liking) at idle or low rpms.

With two mechanical oil pressure sensors you can determine about where the bleed down is happening.

 

[pbbigmac2]

What are the two locations for testing oil pressure? Jasper said “obd2 scanner is inaccurate”. Took it to the shop and they removed the existing pressure sensor to hook up mechanical gauge so not possible to differentiate what the root cause is and let it cool down to be able to even work on it and said “it’s 26psi”.

They swapped in a new GM oil pressure sensor claiming that was the issue. I may purchase my own M16 to 1/8NPT tee and do my own testing cause I feel this cannot be that difficult.

 

[PG01]

Not to be the a-hole here but jasper is crap.

My workplace fleet mechanics have to put them in and they dont last 10-15-20k. Opening them up they have found that although its a fresh looking motor on the outside, internals are a mess. Granted these are Ram trucks (Dodges) not GM but i cant see them being any different. It doesn’t take much to steam clean a motor, slap some stickers on it and call it rebuilt. The mechanics just recently told me jasper is blaming them for the ‘rebuilt’ engine failures and won’t warranty them unless a 3rd party of their choosing installs them. Im not talking about 2-3 engines.. these guys have done upwards of 40-60 motors on our vehicles and they just dont last. (Apparently Ram had engine isssues from 2014 up)
I would get your warranty claim in, hopefully get another engine then start looking for another motor on your own and drop it to a mechanic you trust and let them freshen it up for you.
My 2cents anyway
Good luck

 

[pbbigmac2]

Not to be the a-hole here but jasper is crap.

My workplace fleet mechanics have to put them in and they dont last 10-15-20k. Opening them up they have found that although its a fresh looking motor on the outside, internals are a mess. Granted these are Ram trucks (Dodges) not GM but i cant see them being any different. It doesn’t take much to steam clean a motor, slap some stickers on it and call it rebuilt. The mechanics just recently told me jasper is blaming them for the ‘rebuilt’ engine failures and won’t warranty them unless a 3rd party of their choosing installs them. Im not talking about 2-3 engines.. these guys have done upwards of 40-60 motors on our vehicles and they just dont last. (Apparently Ram had engine isssues from 2014 up)
I would get your warranty claim in, hopefully get another engine then start looking for another motor on your own and drop it to a mechanic you trust and let them freshen it up for you.
My 2cents anyway
Good luck

Not an a-hole, it's genuine feedback. The one thing I have heard about Jasper is that they are great with their warranty... which to be fair, is accurate in my experience. They shipped out a non-AFM engine within 48 hours of the rocker arm diagnosis. That being said, the only way to have a reputation of "great warranty" is if your product consistently does not survive for 3 years/100k miles.

 

[2006Tahoe2WD]

Drove it into my ditch (not sure if enough) and added 2 quarts. Pressure went up a couple PSI.

Going to do the 500 mile oil/oil filter change with a AcDelco filter now and see if that changes anything.

If no change, picked up another GM oil pressure sensor just to rule that out.

Calling Jasper either way tomorrow morning

An idea. Send an oil sample to Blackstone and see if your engine is eating itself. If not then you can address things in a more casual manner.

 

[pbbigmac2]

Yes, I will do my next oil change in a couple thousand miles and send it to Blackstone. Jasper effectively said that when they ran it for 15 min, it was 58 psi (effectively cold). They stated GM spec is 24psi at 1k, however there is no idle spec.

I’ll install the T this weekend and validate the pressures. The sad reality is paying the shop to drop the pan is basically the same cost as replacing another engine under warranty.

 

[2011burbLTZ]

It takes 4 psi to float the crank on these motors, but the lifters would probably need a bit more to stay pumped up. I had a similar issue that your having with a gen 3 (non AFM motor). It was a 5.3 original GM oil pump, aftermarket cam and new top end. The pan was swapped with a new Oring and GM pickup tube. At cold idle 1000rpms or even lower it had 45psi, but once it got hot the oil pressure when to 0psi which happened to me on a long trip and I didn't realize. Likely was not the oil pickup oring but the bypass in the oil pump was likely stuck open. The GM pumps had a nasty tendancy to have the pressure relief valve to get stuck and you would loose oil pressure. When the oil is cold its thick enough to still cause pressure but once it gets hot it thins out and your pressure drops as the relief is big enough to bleed all the pressure. The cure was I put in a Melling 195 HV pump (18% increase), new oring and slapped it back together. Then it had 60psi+ cold and 40psi hot at idle, touch the throttle it would go to 100psi which is the max of my pressure transducer.

I'm not sure when or if GM ever fixed the pump issue but Melling has a redesigned valve that supposedly doesn't allow that to happen anymore. My 2011 suburban with a 132k 5.3 has 35-40psi oil pressure cold, drops to 15-20psi hot idle and will go up to 30-35psi on the throttle. I would love to pull the AFM crap and do an oil pump. Honestly doing an oil pump on these motors is pretty easy but I've never had to work on them in this SUV platform.

On my Gen 3s I usually tap the oil cooler bypass above the oil filter for either another gauge or mechanical gauge fitting. You can also use the port right behind the PS pump on the driver side which is usually where I prelube my motors after a build.