Build thread - LMG 5.3 to L96 6.0 swap

[Scrappycrow]

I know it sounds crazy but the oil filters make quite a difference. The cheaper ones are very restrictive. I started looking into this because someone found a GM service bulletin about low oil pressure CEL popping up and this to be a fix. From what I have read the filter is for the LS9 vette dry sump system.

Great info! Here are a couple of BITOG discussions on the subject:

https://bobistheoilguy.com/forums/threads/5-3-6-0-gm-trucks-losing-oil-pressure-pf48e.286907/

https://bobistheoilguy.com/forums/threads/why-does-a-upf48r-filter-result-in-more-engine-oil-pressure-than-a-pf48e.336787/

BTW, note that your first pair of oil pressures is swapped (the "after" pressure is higher than the "from").

 

[petethepug]

I called Jasper yesterday and gave them that number - they told me the purchase date was July 2022!

I say hellrow to your writtle fweind from 20-22!

 

[DaveO9]

I'd you've turned tbi from the chip days. you might actually enjoy hpt ha.

I finally got around to installing EBL on a tpi car about a year ago. it was so much easier than the old days.

the scanner side of hptuners is probably worth it alone, and the more you sort out filters for the data and what pids to watch. like they have a dynamic air flow pid, it's what the ecm actually uses, some weird mix of the virtual ve table and maf. something you can't see with regular scanners. the hard part for me is the lack of good definitions of what the tables do. feels like the old obd1 days the guys used more logical names and went into details of how the tables functioned. hpt you're kinda on your own to see what's what..

I can't believe I forgot this, but I actually had a WBO2 in my burb, with an in-cab gauge to watch it. Not sure if you are familiar with square body dashes, but they had a flip down ash tray. I installed the WB gauge right inside, so I could close it up when I didn't want to see those numbers bouncing around all the time. It was pretty cool, but I don't think I ever had it wired into the inputs of the ecm, so I couldn't really track it in the logs. That was an upcoming project, but I ended up selling it before I could do it. I seem to remember a challenge with lack of an input for it, as I had everything used up.

I finally found out a way to get the oil pressure up to where I feel it's supposed to be, I thought this would be useful information to you and something you might consider to try on your engine since you have the same lower pressure at idle. I have been trying to figure this out since I built my first engine in the Sierra (5.3l LC9) and it had the similar low oil pressure after it was fully warmed up and would sit at around 16-18psi idle. Even though everything was brand new in that engine I changed the pickup oring, shimmed the M365 pump and nothing would change the idle pressure. I found this L96 cheap and thought it would be a good time to pull the 5.3l and go through it. So I took the 179k mile L96 and changed the major gaskets and seals and threw it in the truck...... Same oil pressure at idle...

I installed a dual channel oil pressure gauge, one at the front driver side of the engine (oil pump outlet) and one tee'd off of the back top engine block where the factory pressure sending unit is (after filter and oil cooler). I also tested the new dual channel gauge with a calibrated factory pressure sensor to make sure that it was accurate readings.

Using a ACDelco PF48B filter (fully warmed up oil driven over 30 minutes before readings were taken - Both days were within 2 degrees ambient temp 75ish)

@ Idle
From oil pump 35PSI
After oil cooler and filter 20PSI

@2000rpm driving
From oil pump 50PSI
After oil cooler and filter 30PSI

Using a ACDelco UPF48R filter

@ Idle
From oil pump 32PSI
After oil cooler and filter 28PSI

@2000rpm driving
From oil pump 48PSI
After oil cooler and filter 40PSI

I know it sounds crazy but the oil filters make quite a difference. The cheaper ones are very restrictive. I started looking into this because someone found a GM service bulletin about low oil pressure CEL popping up and this to be a fix. From what I have read the filter is for the LS9 vette dry sump system.

Great info! I just ordered the UPF48R for my next oil change, but now I wonder if I should have tried the 48B first. I did a little research tonight - the "e" filters have a plastic core that doesn't stand up to heat as well as the more expensive/traditional metal core filters.

 

[DaveO9]

Last Tuesday I got back from a 1500 mile roundtrip pulling my travel trailer. My oldest goes to school in the CA bay area, so we camped for three nights on the way down, and then I camped for three more nights on the way back. This was the second time I've done this trip with the trailer, but the first time was with the 5.3 so it made for a good comparison. Some quick comments on how the truck did.

General performance - great! The additional torque of the 6.0 eliminated many downshifts to 3rd going up grades, and easily allowed 5th gear on flats and even slight grades. (but I'd go to fourth as soon as I heard the exhaust note change meaning the TC unlocked). the 5.3 would not pull the trailer in 5th even on the flat, unless I was going 65 or so. But the engine swap did not produce any miracles. I was still going down to 3rd on the 6% grades and dropping speed to 50 mph.

Mileage - I kept track of every fill up and total mileage. Overall it was 10.2 mpg for the entire trip. All but 200 miles of the 1500 pulling the 4500 lbs trailer. I'm fairly pleased. I don't think I kept track as well the first time I did the trip, but pretty sure it wasn't any better, may have been a little worse. But... this is WA, OR, and CA we're talking about - my average price paid was $5.20/gallon and I spent $800+ on gas alone. Ouch. (And about 75% of those gallons were Costco fuel, too) She's a senior this year, so I'm thinking that was the last travel trailer trip down there for a while.

Engine cooling - I think I may have to upgrade to the K5L fans. I came close to the 225 mark on the gauge pulling the steepest grades, which happened to be when I experienced the highest ambients of the trip - mid to high 90s. Was watching gauge like a hawk and never got any warnings in the DIC, but it still had me nervous. I have the bigger Denso radiator that is two years old, water pump is brand new GM. Would the K5L fans help? It did cool down quick when I crested, or even if I stopped and let it idle. I know there are threads on here about the fan upgrade, just haven't had time to read through them yet. Engine cooling was fine other than those steep grades - 90% of the trip it stayed at 210.

Trans cooling - I think the highest I ever hit was 220 or just below, so I wasn't as worried about the trans this time. And the 220 was just for a few minutes at most. Normal driving in 4th or 5th (TC locked) it would stay at 200 or below.

Overall I felt it was pretty successful. Zero CELs, codes, or DIC warnings, no side of the road stoppages. Trailer did well, too, although every trip I find additional things that need to be rectified. (20 years old).

 

[Scrappycrow]

I just ordered the UPF48R for my next oil change, but now I wonder if I should have tried the 48B first. I did a little research tonight - the "e" filters have a plastic core that doesn't stand up to heat as well as the more expensive/traditional metal core filters.

Have you considered going to the PF63 size? Even with the same filter media as a PF48, you'll have less pressure drop due to the greater filter area.

FWIW I'm running Baldwin 7449.

 

[Marky Dissod]

Engine cooling - I think I may have to upgrade to the K5L fans. I came close to 225F pulling the steepest grades,
which happened to be when I experienced the highest ambients of the trip - mid to high 90s. Was watching gauge like a hawk and never got any warnings in the DIC,
but it still had me nervous. I have the bigger Denso radiator that is two years old, water pump is brand new GM. Would the K5L fans help?
It did cool down quick when I crested, or even if I stopped and let it idle. I know there are threads on here about the fan upgrade,
just haven't had time to read through them yet. Engine cooling was fine other than those steep grades - 90% of the trip it stayed at 210F.

If the gauge came close to 225F, best believe that SOME of the ATF was hotter than that; GM puts the ATF temp sensor where it's easy to put, not in the hottest spot.
Of course the K5L fans will help, just make sure the wiring is up to the task.
It would also help if you did not settle for GM OE fan temp settings.

Lastly, there is such a thing as 'Hot Mode', but GM's setting of 266F is too late to be useful ...

 

[58nate]

I can't believe I forgot this, but I actually had a WBO2 in my burb, with an in-cab gauge to watch it. Not sure if you are familiar with square body dashes, but they had a flip down ash tray. I installed the WB gauge right inside, so I could close it up when I didn't want to see those numbers bouncing around all the time. It was pretty cool, but I don't think I ever had it wired into the inputs of the ecm, so I couldn't really track it in the logs. That was an upcoming project, but I ended up selling it before I could do it. I seem to remember a challenge with lack of an input for it, as I had everything used up.

Great info! I just ordered the UPF48R for my next oil change, but now I wonder if I should have tried the 48B first. I did a little research tonight - the "e" filters have a plastic core that doesn't stand up to heat as well as the more expensive/traditional metal core filters.

I've run the 48B, 48E, Bosch 3334, and Wix 57060 with the same low oil pressure. The 48R is the only filter I have tried between the two engines and 2 years of trying to get my idle pressure where it should be. I did see someone saying the Mobile 1 high performance filter was the same but it costs more than the 48R. Rockauto sells the 48R for $7.52, but you have to order several to make the shipping worth while. I'm probably going to cut them both open and get a better understanding if it's the filter media or design.

 

[DaveO9]

Have you considered going to the PF63 size? Even with the same filter media as a PF48, you'll have less pressure drop due to the greater filter area.

FWIW I'm running Baldwin 7449.

I have run the PF63 previously - I almost ordered it last night, but I want to try the UPF48R to see what it does to my oil pressure.

If the gauge came close to 225F, best believe that SOME of the ATF was hotter than that; GM puts the ATF temp sensor where it's easy to put, not in the hottest spot.
Of course the K5L fans will help, just make sure the wiring is up to the task.
It would also help if you did not settle for GM OE fan temp settings.

Lastly, there is such a thing as 'Hot Mode', but GM's setting of 266F is too late to be useful ...

It was engine temp that was kissing the 225 mark on the analog gauge - hottest trans temps were 217-219, IIRC. But I get your drift.

Regarding the bigger fans, the reason I asked is I was going 45-50 mph at this time, and was wondering if airflow from speed would be overpowering the fans at that speed anyway. Fans that move more air are big time helpful for crawling along in traffic, but maybe not as useful when slowest speed is 45 mph?? It would take less than a minute after cresting a big hill for the engine temp to start dropping back to 210-215.

 

[Marky Dissod]

Somewhere between 45MpH & 50MpH the passive headwind airflow overpowers whatever any electric fan motor can generate,
provided the baffle panels that prevent air from getting around the radiator are all in place.

Prior to GMT900, no GM ecms or pcms would leave a fan motor on at/over 49MpH.
(In fact fan motor duty cycle never exceeds 60% over 35MpH for the same reason.)

A downshift may be called for? Even if the vehicle can overcome the load and maintain speed, point is to spin H2Opump fast enough to cool the powertrain.

 

[DaveO9]

A downshift may be called for? Even if the vehicle can overcome the load and maintain speed, point is to spin H2Opump fast enough to cool the powertrain.

No, no downshift in this scenario - I was in third and it was well over 3k rpm. I'm still going to consider the fan upgrade, but it might take a backseat to other things for a while, i.e. next spring in prep for towing season. You mentioned the wiring to the fans - is it different for the K5L option?

 

[Joseph Garcia]

No, no downshift in this scenario - I was in third and it was well over 3k rpm. I'm still going to consider the fan upgrade, but it might take a backseat to other things for a while, i.e. next spring in prep for towing season. You mentioned the wiring to the fans - is it different for the K5L option?

From what I have seen, to convert to the 700 watt cooling system from the 500 watt cooling system, you only need the 2 fan motors, the 2 fan blades, and the fan shroud. The electrical connectors are the same.

 

[DaveO9]

From what I have seen, to convert to the 700 watt cooling system from the 500 watt cooling system, you only need the 2 fan motors, the 2 fan blades, and the fan shroud. The electrical connectors are the same.

Cool! (pun intended) thank you!

 

[DaveO9]

Finally pulled the trigger on HPT. OBD2 dongle and cable, along with two universal credits supposed to arrive tomorrow!

 

[kbuskill]

Finally pulled the trigger on HPT. OBD2 dongle and cable, along with two universal credits supposed to arrive tomorrow!

You won't be disappointed. Although I will say there is a TON of things you can mess with, so my suggestion is to not do too much at once and save a file for every change so you can always revert back to something that works. And don't forget to save a copy of the original tune just in case.